阅读说明：本技术 作为声音发射器的显示器的反馈控制 (Feedback control of display as sound emitter ) 是由 R·D·J·伯纳尔·卡斯蒂洛 W·海姆比格纳 D·拉马克里希南 A·G·舍夫西 柳相昱 于 2020-02-21 设计创作，主要内容包括：本公开的各方面涉及使用显示器作为声音发射器并且可以涉及包括显示器的电子设备。特别地,诸如加速度计等振动传感器物理地耦合到显示器并且感测显示器振动以提供关于表示来自显示器的实际音频输出的高精度反馈回路。该电子设备包括致动器,该致动器物理地耦合到显示器并且被配置为响应于音频信号而引起显示器的振动。该电子设备还包括振动传感器,该振动传感器物理地耦合到显示器并且被配置为输出振动传感器信号,该振动传感器信号与由于致动器而引起的显示器的振动成比例。(Aspects of the present disclosure relate to using a display as a sound emitter and may relate to an electronic device including a display. In particular, a vibration sensor, such as an accelerometer, is physically coupled to the display and senses display vibrations to provide a high precision feedback loop regarding the actual audio output from the display. The electronic device includes an actuator physically coupled to the display and configured to cause vibration of the display in response to an audio signal. The electronic device also includes a vibration sensor physically coupled to the display and configured to output a vibration sensor signal proportional to a vibration of the display due to the actuator.)

1. An electronic device, comprising:

a display;

an actuator physically coupled to the display and configured to: causing vibration of the display in response to an audio signal that is an input to the actuator and that is generated by an audio amplifier; and

a vibration sensor physically coupled to the display and configured to: the vibration of the display due to the actuator is sensed and a vibration sensor signal is output that is proportional to the vibration of the display due to the actuator.

2. The electronic device of claim 1, further comprising:

the audio amplifier operably coupled to the actuator;

a processor operatively coupled to the vibration sensor and configured to receive the vibration sensor signal as an input, the processor further operatively coupled to the audio amplifier; and

a microphone operatively coupled to the processor.

3. The electronic device defined in claim 2 wherein the processor is configured to adjust a microphone output signal output from the microphone based on the vibration sensor signal.

4. The electronic device of claim 1, wherein the vibration sensor is an accelerometer.

5. The electronic device of claim 4, wherein the accelerometer is a broadband accelerometer having a bandwidth that covers frequencies within a voice frequency range.

6. The electronic device of claim 1, further comprising:

an audio codec operatively coupled to the vibration sensor and configured to output a digital vibration sensor signal based on the vibration sensor signal; and

a processor operatively coupled to the audio codec and configured to generate a sound pressure level signal based on the digital vibration sensor signal.

7. The electronic device of claim 1, further comprising a processor operatively coupled to the vibration sensor, wherein the processor is configured to generate an echo reference signal based on the vibration sensor signal.

8. The electronic device of claim 7, wherein the echo reference signal represents an acoustic output of the display due to the vibration of the display.

9. The electronic device of claim 7, wherein the processor is configured to cancel at least a portion of an echo signal included within a microphone output signal output by a microphone of the electronic device, the processor configured to cancel the at least a portion of the echo signal based on the echo reference signal, the echo reference signal generated based on the vibration sensor signal from the vibration sensor.

10. The electronic device of claim 9, wherein the processor is configured to cancel the echo signal based further on a signal from an output of the audio amplifier, the audio amplifier operably coupled between the actuator and the processor.

11. The electronic device of claim 9, wherein the echo signal represents an acoustic output of the display due to the vibration of the display captured by the microphone.

12. The electronic device of claim 9, wherein the echo reference signal based on the vibration sensor signal comprises at least one of: harmonic distortion, or group delay, caused by the display.

13. The electronic device of claim 1, further comprising:

a processor operatively coupled to the vibration sensor and configured to receive the vibration sensor signal as an input; and

a microphone operatively coupled to the processor and configured to output a microphone output signal, the processor configured to cancel a portion of the microphone output signal based on the vibration sensor signal.

14. The electronic device of claim 13, wherein the portion of the microphone output signal that is cancelled corresponds to acoustic output from the display due to vibration of the display captured by the microphone.

15. The electronic device defined in claim 1 further comprising a processor operably coupled to the vibration sensor, wherein the processor is configured to condition an electrical audio signal provided to the audio amplifier to generate the audio signal, the processor configured to condition the electrical audio signal based on the vibration sensor signal from the vibration sensor.

16. The electronic device defined in claim 15 wherein the processor is configured to adjust a frequency response of the electrical audio signal provided to the audio amplifier based on the vibration sensor signal to provide an adjusted acoustic output from the display.

17. The electronic device of claim 15, wherein the processor is configured to:

converting the vibration sensor signal to a sound pressure level signal;

comparing the sound pressure level signal to a target sound pressure level model representing audio output characteristics of the display; and

Adjusting a frequency response of an electrical audio signal provided to the audio amplifier based on the comparison.

18. The electronic device of claim 1, wherein the vibration sensor signal differs from the audio signal at an input of the actuator based at least on a transfer function that represents the vibration of the display in response to the audio signal.

19. The electronic device of claim 1, wherein the vibration sensor signal is different from the audio signal at the input of the actuator based at least in part on a physical dimension or structural characteristic of the display.

20. The electronic device of claim 1, further comprising:

a second actuator physically coupled to a portion of the electronic device that is different from a location at which the actuator is physically coupled to the display, and configured to cause vibration of the portion in response to a second audio signal;

a second vibration sensor physically coupled to the portion of the electronic device and configured to output a second vibration sensor signal proportional to the vibration of the portion.

21. The electronic device of claim 20, further comprising a processor configured to: adjusting the second audio signal based on at least one of the vibration sensor signal or the second vibration sensor signal, or a combination thereof.

22. The electronic device of claim 1, further comprising:

an actuator array comprising the actuators, each actuator of the actuators in the array configured to: causing vibrations of different portions of the electronic device in response to respective audio signals received by the actuator; and

a vibration sensor array comprising the vibration sensors, each of the vibration sensors in the array configured to: outputting respective vibration sensor signals proportional to the vibrations of the different portions of the electronic device.

23. The electronic device defined in claim 1 wherein the vibration sensor is positioned adjacent to the actuator.

24. The electronic device defined in claim 1 wherein the audio signal represents an audio speech signal and wherein the display is configured to provide acoustic output corresponding to the audio speech signal due to the vibration of the display.

25. The electronic device of claim 1, wherein the audio signal is an amplified electrical audio signal generated by the audio amplifier based on an electrical audio signal generated by a processor.

26. An electronic device, comprising:

a display;

means for providing an acoustic output from the display due to vibration of the display based on an audio signal generated by an audio amplifier causing the vibration of the display;

means for sensing the vibration of the display, the vibration sensing means configured to output a vibration sensor signal proportional to the vibration of the display in response to the vibration of the display.

27. The electronic device of claim 26, further comprising: means for generating an echo reference signal based on the vibration sensor signal, the echo reference signal representing an acoustic output of the display due to the vibration of the display.

28. The electronic device of claim 27, further comprising: means for cancelling at least a portion of an echo signal included within a microphone output signal output by a microphone, the cancelling means configured to cancel the at least a portion of the echo signal based on the echo reference signal, the echo reference signal generated based on the vibration sensor signal from the vibration sensing device.

29. The electronic device of claim 26, further comprising: means for adjusting an electrical audio signal provided to the audio amplifier based on the vibration sensor signal.

30. A method for generating audio using a display, the method comprising:

using an actuator physically coupled to the display, vibrating the display based on an audio signal provided as an input to the actuator and generated by an audio amplifier; and

using a vibration sensor physically coupled to the display, a vibration sensor signal is generated that is proportional to a vibration of the display due to the actuator.

31. The method of claim 30, further comprising: generating an echo reference signal based on the vibration sensor signal, the echo reference signal representing an acoustic output of the display due to vibration of the display.

32. The method of claim 31, further comprising: canceling at least a portion of an echo signal included within a microphone output signal output by a microphone, wherein canceling the at least a portion of the echo signal includes canceling the at least a portion of the echo signal based on the echo reference signal, the echo reference signal generated based on the vibration sensor signal from the vibration sensor.

33. The method of claim 32, wherein the echo signal represents an acoustic output of the display captured by the microphone.

34. The method of claim 30, further comprising: canceling a portion of a microphone output signal output from a microphone based on the vibration sensor signal, the portion canceled corresponding to acoustic output from the display due to vibration of the display captured by the microphone.

35. The method of claim 30, further comprising: adjusting an electrical audio signal provided to the audio amplifier based on the vibration sensor signal from the vibration sensor.

36. The method of claim 35, wherein conditioning the electrical audio signal comprises: adjusting a frequency response of the electrical audio signal based on the vibration sensor signal from the vibration sensor.

37. The method of claim 30, wherein the vibration sensor is a broadband accelerometer having a bandwidth covering frequencies within a voice frequency range.

38. The method of claim 30, further comprising: the vibration sensor signal is converted to a sound pressure level signal and the audio signal is adjusted based on the sound pressure level signal.

39. The method of claim 38, further comprising: generating an adjusted sound pressure level signal based on comparing the sound pressure level signal to a target sound pressure level model representing audio output characteristics of the display, the method comprising adjusting the audio signal based on the adjusted sound pressure level signal.

40. An electronic device, comprising:

an actuator operatively coupled to a component of the electronic device having an externally facing surface, the actuator configured to cause vibration of the component in response to an audio signal generated by an audio amplifier; and

a vibration sensor coupled to the component and configured to: outputting a signal proportional to the vibration of the component in response to the vibration of the component by the actuator.

Technical Field

The present disclosure relates generally to a system for producing sound using a display, and in particular to a system for a feedback loop used to improve the audio output of vibrations from a display.

Background

Electronic devices include traditional computing devices such as desktop computers, notebook computers, tablet computers, smart phones, wearable devices such as smart watches, internet servers, and the like. However, electronic devices also include other types of devices with computing capabilities, such as personal voice assistants, thermostats, automotive electronics, robots, devices embedded in other machines (e.g., household appliances and industrial tools), internet of things (IoT) devices, and so forth. These various electronic devices provide information, entertainment, social interactions, security, productivity, transportation, manufacturing, and other services for human users.

These electronic devices typically include a display along with functionality for outputting audio (e.g., for voice call or audio playback functionality). In some cases, it is desirable to extend the size of the display to as large an extent as possible (e.g., to have the display cover the entire front (or other surface) of the electronic device). However, a space-consuming audio speaker may also be required to output sound to a user facing the display. It may be desirable for the system to be able to provide audio output without taking up space on the surface of the device to allow more area for the display (e.g., to allow the display to extend to all of the outer edges of the electronic device).

Disclosure of Invention

In one aspect of the present disclosure, an electronic device is provided. The electronic device includes a display. The electronic device also includes an actuator physically coupled to the display and configured to: the vibration of the display is caused in response to an audio signal that is an input to the actuator and is generated by the audio amplifier. The electronic device also includes a vibration sensor physically coupled to the display and configured to sense vibration of the display due to the actuator and output a vibration sensor signal proportional to the vibration of the display due to the actuator. In some implementations, the electronic device may further include a processor operatively coupled to the vibration sensor, wherein the processor is configured to generate the echo reference signal based on the vibration sensor signal. The echo reference signal corresponds to a representation of an acoustic output (e.g., an audio output) of the display due to vibration of the display. In some implementations, the processor may be further configured to cancel at least a portion of an echo signal included within a microphone input signal received by the microphone, wherein the processor is configured to cancel at least a portion of the echo signal based on an echo reference signal, the echo reference signal generated based on a vibration sensor signal from the vibration sensor.

In another aspect of the present disclosure, an electronic device is provided. The electronic device includes a display. The electronic device further includes: means for providing an acoustic output from the display due to the vibration of the display based on the display being caused to vibrate by an audio signal generated by the audio amplifier. The electronic device also includes means for sensing vibration of the display. The vibration sensing device is configured to output a vibration sensor signal proportional to vibration of the display in response to the vibration of the display. In some implementations, the electronic device may further include: means for generating an echo reference signal based on the vibration sensor signal. The echo reference signal corresponds to a representation of the acoustic output of the display. The electronic device may further include: means for cancelling at least a portion of an echo signal comprised within a microphone input signal received by a microphone, wherein the cancelling means is configured to cancel at least a portion of the echo signal based on an echo reference signal, the echo reference signal being generated based on a vibration sensor signal from a vibration sensing device.

In yet another aspect of the present disclosure, a method of generating audio using a display is provided. The method comprises the following steps: the display is vibrated using an actuator physically coupled to the display based on an audio signal provided as an input to the actuator and generated by an audio amplifier. The method further comprises the following steps: a vibration sensor physically coupled to the display is used to generate a vibration sensor signal. The vibration sensor signal is proportional to the vibration of the display due to the actuator. In some implementations, the method may further include generating an echo reference signal based on the vibration sensor signal, the echo reference signal corresponding to a representation of an acoustic output of the display. The method may further include canceling at least a portion of an echo signal included within a microphone input signal received by the microphone, wherein canceling at least a portion of the echo signal includes canceling at least a portion of the echo signal based on an echo reference signal, the echo reference signal generated based on a vibration sensor signal from the vibration sensor.

In yet another aspect of the disclosure, a computer-readable medium storing computer-executable code is provided. The code, when executed by a processor, causes the processor to: the display is vibrated using an actuator physically coupled to the display based on an audio signal provided as an input to the actuator. The code also causes the processor to: a vibration sensor physically coupled to the display is used to generate a vibration sensor signal. The vibration sensor signal is proportional to the vibration of the display due to the actuator. In some implementations, the code may also cause the processor to generate an echo reference signal based on the vibration sensor signal, the echo reference signal corresponding to a representation of an acoustic output of the display. The code may also cause the processor to cancel at least a portion of an echo signal included within a microphone input signal received by the microphone, wherein canceling at least a portion of the echo signal includes canceling at least a portion of the echo signal based on an echo reference signal, the echo reference signal generated based on a vibration sensor signal from the vibration sensor.

In yet another aspect of the present disclosure, an electronic device is provided. The electronic device includes an actuator operatively coupled to a component of the electronic device having an externally facing surface. The actuator is configured to cause vibration of the component in response to an audio signal generated by the audio amplifier. The electronic device also includes a vibration sensor coupled to the component and configured to output a signal proportional to vibration of the component in response to vibration of the component by the actuator.

In yet another aspect of the present disclosure, an electronic device including a display is provided. The electronic device also includes an actuator physically coupled to the display and configured to: the vibration of the display is caused in response to an audio signal provided as an input to the actuator. The electronic device also includes a vibration sensor physically coupled to the display and configured to: a vibration sensor signal proportional to vibration of the display due to the actuator is output. The electronic device also includes a processor operatively coupled to the vibration sensor. The processor is configured to adjust the audio signal based on the vibration sensor signal from the vibration sensor. In some implementations, the processor may be further configured to adjust the audio signal in response to a force applied to the display that affects vibration of the display. The processor may be configured to determine an estimate of a level of force applied to the display based on the vibration sensor signal. The processor may be configured to adjust the audio signal based on the estimate of the level of force.

In yet another aspect of the present disclosure, an electronic device including a display is provided. The electronic device further includes: means for causing vibration of the display based on the audio signal to provide an acoustic output from the display due to the vibration of the display. The electronic device also includes means for sensing vibration of the display, the vibration sensing means configured to output, in response to the vibration of the display, a vibration sensor signal proportional to the vibration of the display. The electronic device further includes: means for adjusting the audio signal based on the vibration sensor signal from the vibration sensing means. In some implementations, the adjustment device may be configured to adjust the audio signal in response to a force applied to the display that affects vibration of the display. The electronic device may further include: means for determining an estimate of a level of force applied to the display based on the vibration sensor signal. The adjustment device may be configured to adjust the audio signal based on the estimate of the level of force.

In yet another aspect of the present disclosure, a method of generating audio using a display is provided. The method comprises the following steps: the display is vibrated using an actuator physically coupled to the display based on an audio signal provided as an input to the actuator. The method further comprises the following steps: a vibration sensor physically coupled to the display is used to generate a vibration sensor signal that is proportional to the vibration of the display due to the actuator. The method also includes adjusting the audio signal based on the vibration sensor signal from the vibration sensor. In some implementations, conditioning the audio signal may include: the audio signal is adjusted in response to a force applied to the display that affects vibration of the display by the actuator. The method may further include determining an estimate of a level of force applied to the display based on the vibration sensor signal. Adjusting the audio signal may include adjusting the audio signal based on the estimate of the level of force.

In yet another aspect of the disclosure, a computer-readable medium storing computer-executable code is provided. The code, when executed by a processor, causes the processor to: the display is vibrated using an actuator physically coupled to the display based on an audio signal provided as an input to the actuator. The code also causes the processor to: a vibration sensor physically coupled to the display is used to generate a vibration sensor signal that is proportional to the vibration of the display due to the actuator. The code also causes the processor to adjust the audio signal based on the vibration sensor signal from the vibration sensor. In some implementations, conditioning the audio signal may include: the audio signal is adjusted in response to a force applied to the display that affects vibration of the display by the actuator. The code may also cause the processor to determine an estimate of a level of force applied to the display based on the vibration sensor signal. Adjusting the audio signal may include adjusting the audio signal based on the estimate of the level of force.

In yet another aspect of the present disclosure, an electronic device including a display is provided. The electronic device also includes a first actuator physically coupled to the display and configured to: the vibration of the display is caused in response to a first audio signal provided as an input to the first actuator. The electronic device also includes a vibration sensor physically coupled to the display and configured to: a vibration sensor signal proportional to vibration of the display due to the first actuator is output. The electronic device also includes a second actuator physically coupled to a portion of the electronic device that is different from a location where the first actuator is physically coupled to the display and configured to cause vibration of the portion in response to a second audio signal provided as an input to the second actuator. In some implementations, the electronic device may also include a processor configured to generate the first audio signal and the second audio signal. The processor may be configured to generate a second audio signal having a waveform that cancels vibration of the portion of the electronic device caused by vibration of the display.

In yet another aspect of the present disclosure, an electronic device including a display is provided. The electronic device further includes: first means for providing an acoustic output from the display due to the vibration of the display based on the first audio signal causing the vibration of the display. The electronic device also includes means for sensing vibration of the display, the vibration sensing means configured to output a vibration sensor signal proportional to the vibration of the display. The electronic device further includes: a second means for causing a portion of the electronic device other than the display to vibrate based on a second audio signal. In some implementations, the electronic device may further include: means for generating a second audio signal having a waveform that cancels vibration of the portion of the electronic device caused by the vibration of the display, wherein the second audio signal is generated based in part on the vibration sensor signal from the vibration sensing means.

In yet another aspect of the disclosure, a method of generating audio using a display that is part of an electronic device is provided. The method comprises the following steps: the display is vibrated using a first actuator physically coupled to the display based on a first audio signal provided as an input to the first actuator. The method further comprises the following steps: a vibration sensor physically coupled to the display is used to generate a vibration sensor signal that is proportional to the vibration of the display due to the first actuator. The method further comprises the following steps: using a second actuator physically coupled to a portion of the electronic device other than the display, vibrating the portion of the electronic device based on a second audio signal provided as an input to the second actuator. In some implementations, the method may further include generating a second audio signal having a waveform that cancels vibration of the portion of the electronic device due to vibration of the display.

In yet another aspect of the disclosure, a computer-readable medium storing computer-executable code is provided. The code, when executed by the processor, causes the processor to vibrate the display using a first actuator physically coupled to the display based on a first audio signal provided as an input to the first actuator. The code also causes the processor to generate a vibration sensor signal using a vibration sensor physically coupled to the display, the vibration sensor signal proportional to vibration of the display due to the first actuator. The code also causes the processor to vibrate a portion of the electronic device different from the display based on a second audio signal provided as input to a second actuator using the second actuator physically coupled to the portion of the electronic device. In some implementations, the code may also cause the processor to generate a second audio signal having a waveform that causes the vibration of the portion of the electronic device caused by the vibration of the display to cancel.

Drawings

FIG. 1 is a diagram of an environment including an electronic device with a display and an audio system.

Fig. 2 is a block diagram of an example of an audio system for using a display as an audio transmitter of an electronic device.

Fig. 3A and 3B are block diagrams of examples for an audio system using a display as an audio emitter, the audio system including a vibration sensor, according to certain aspects of the present disclosure.

Fig. 4A is a block diagram of an example of an audio system corresponding to the audio system of fig. 3, showing other functional elements or components of the processor.

Fig. 4B is a block diagram of the audio system of fig. 4A showing other examples of functional elements or components of the processor.

Fig. 5A is a graph illustrating a comparison between a vibration sensor signal from a vibration sensor and a measured sound pressure level signal across a frequency range for different sound intensity levels.

Fig. 5B is a diagram illustrating a representation of an audio signal across frequencies based on different forces applied to a display.

Fig. 6 is a graph showing changes in Q-factor of an electromechanical system including a display and an actuator as a result of different external forces applied to the display.

Fig. 7 is a block diagram of an example of an audio system using a display as an audio transmitter including a vibration sensor and echo cancellation according to certain aspects of the present disclosure.

Fig. 8A is a block diagram of an example of an audio system using a display as an audio emitter, including a vibration sensor and sound leakage cancellation, according to certain aspects of the present disclosure.

Fig. 8B is a block diagram of the audio system of fig. 8A showing other examples of functional elements or components of the processor.

Fig. 8C is a block diagram of another example of an audio system using a display as an audio emitter, the audio system including two vibration sensors, according to certain aspects of the present disclosure.

Fig. 8D is a block diagram of the audio system of fig. 8C showing other examples of functional elements or components of the processor.

Fig. 9 shows an example of the audio system of fig. 8C, but with the back panel replaced with a second display.

Fig. 10 shows an example of an audio system similar to that of fig. 3A, but with the display replaced with a generic component.

Fig. 11 is a flowchart illustrating an example of a method for generating audio using the display with reference to fig. 4A and 4B.

FIG. 12 is a flow chart illustrating another example of a method for generating audio using a display.

FIG. 13 is a flow chart illustrating another example of a method for generating audio using a display that is part of an electronic device.

FIG. 14 is a flow chart illustrating an example of a method for processing a vibration sensor signal from a vibration sensor.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary implementations and is not intended to represent the only implementations in which the present invention may be practiced. The term "exemplary" as used throughout this specification means "serving as an example, instance, or illustration," and should not necessarily be construed as preferred or advantageous over other exemplary implementations. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary implementations. In some cases, some devices are shown in block diagram form. Common drawing elements in the following figures may be identified with the same reference numerals.

Aspects of the present disclosure relate to using a display as a sound emitter, for example, for making phone calls on an electronic device such as a smartphone. In certain aspects, systems that use a display as a sound emitter are referred to as display-receiver (DaR) systems, which are intended to replace dynamic receivers (e.g., speakers) that play sound (or for other audio playback) in a handset mode call. Replacing the speaker and enabling the display to be a sound emitter allows the entire front or other surface of the electronic device to be used as a display. Thus, no acoustic port on the front of the electronic device is required, leaving more room for the display. This is an ideal design feature for electronic devices. Furthermore, for smaller electronic devices, it may be desirable to use space for purposes other than acoustic ports. In one aspect, the DaR system is an electromechanical system that generates sound by applying vibrations at the back of the display. In certain aspects, the vibration of the display is of the following type: that is, sound waves are generated in the air based on audible vibrations (e.g., acoustic output), and the vibrations of the display may or may not be physically felt by the user when the user touches the electronic device. However, producing sound through a display can present challenges in maintaining audio output quality. Aspects of the present disclosure relate to providing accurate feedback of audio output of a display to improve overall audio quality. While certain aspects of the present disclosure relate to outputting sound using a display, it should be understood that the principles described herein may also be applied to other components of an electronic device (e.g., other surfaces or externally facing components of a housing) that may be caused to vibrate to produce an audio output.

For example, an element or any portion of an element or any combination of elements described herein may be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, Graphics Processing Units (GPUs), Central Processing Units (CPUs), application processors, Digital Signal Processors (DSPs), Reduced Instruction Set Computing (RISC) processors, systems on chip (socs), baseband processors, Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in the processing system may execute software. Software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software components, applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referring to software, firmware, middleware, microcode, hardware description languages, or otherwise.

Thus, in one or more example embodiments, the described functions or circuitry blocks may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer readable media includes computer storage media. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise Random Access Memory (RAM), Read Only Memory (ROM), electrically erasable programmable ROM (eeprom), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the above types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer. In some aspects, components described with circuitry may be implemented by hardware, software, or any combination thereof.

Fig. 1 is a diagram of an environment 100 including an electronic device 102 having a display 120 and an audio system 122. In the environment 100, an electronic device 102 communicates with a base station 104 over a wireless link 106. As shown, the electronic device 102 is depicted as a smartphone. However, the electronic device 102 may be implemented as any suitable computing device or other electronic device, such as a cellular base station, a broadband router, an access point, a cellular or mobile phone, a gaming device, a navigation device, a media device, a laptop computer, a desktop computer, a tablet computer, a server computer, a Network Attached Storage (NAS) device, a smart appliance, a vehicle-based communication system, an internet of things (IoT) device, a sensor or security device, an asset tracker, and so forth.

The base station 104 communicates with the electronic device 102 via a wireless link 106, which wireless link 106 may be implemented as any suitable type of wireless link. Although depicted as a base station tower of a cellular radio network, base station 104 may represent or be implemented as another device, such as a satellite, a terrestrial broadcast tower, an access point, a peer device, a meshA network node, a fiber optic line, another electronic device substantially as described above, or the like. Thus, the electronic device 102 may communicate with the base station 104 or another device via a wired connection, a wireless connection, or a combination thereof. The wireless link 106 may include a downlink for data or control information transmitted from the base station 104 to the electronic device 102 and an uplink for other data or control information transmitted from the electronic device 102 to the base station 104. The wireless link 106 may be implemented using any suitable communication protocol or standard, such as third generation partnership project long term evolution (3GPP LTE, 3GPP NR 5G), IEEE 802.11, IEEE 802.16, Bluetooth ^TMAnd the like.

The electronic device 102 includes a processor 108 and a memory 110. The memory 110 may be or form part of a computer-readable storage medium. The processor 108 may include any type of processor, such as an application processor or a multi-core processor, configured to execute processor-executable instructions (e.g., code) stored by the memory 110. Memory 110 may include any suitable type of data storage media, such as volatile memory (e.g., Random Access Memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., a disk or tape), and so forth. In the context of the present disclosure, the memory 110 is implemented to store the instructions 112, data 114, and other information of the electronic device 102, and thus when configured as a computer-readable storage medium or portion thereof, the memory 110 does not include a transitory propagating signal or carrier wave. In the examples below, although the processor 108 may be depicted without the memory 110, it should be understood that in each of the examples below, the processor may include a memory, such as the memory 110 of fig. 1, that may be used to store the instructions 112, data 114, and other information in a manner that performs a portion or all of any function or operation as indicated by the functional blocks or circuitry blocks.

The electronic device 102 may also include input/output ports 116(I/O ports 116). The electronic device 102 also includes a display 120. The I/O ports 116 enable exchange or interaction of data with other devices, networks, or users or device components. The I/O ports 116 can include a serial port (e.g., a Universal Serial Bus (USB) port), a parallel port, an audio port, an Infrared (IR) port, a camera or other sensor port, and so forth. The display 120 may be implemented as a screen or projection that presents graphics of the electronic device 102, such as a user interface associated with an operating system, program, or application. Alternatively or additionally, the display 120 may be implemented as a displayport or virtual interface through which graphical content of the electronic device 102 is communicated or presented.

The electronic device 102 may also include a Signal Processor (SP)118 (e.g., such as a Digital Signal Processor (DSP)). The signal processor 118 functions similarly to a processor, and the signal processor 118 can execute instructions and/or process information in conjunction with the memory 110. In some aspects, the processor 108 may be a signal processor 118. In other aspects, the processor 108 may include a signal processor 118.

For communication purposes, the electronic device 102 also includes a modem 136, a wireless transceiver 138, and an antenna (not shown). The wireless transceiver 138 provides connectivity to a corresponding network and other electronic devices connected to the wireless transceiver 138 using Radio Frequency (RF) wireless signals. Additionally or alternatively, the electronic device 102 may include a wired transceiver, such as an ethernet or fiber optic interface, for communicating over a personal or local network, an intranet, or the internet. The wireless transceiver 138 may facilitate communication over any suitable type of wireless network, such as a wireless Local Area Network (LAN) (WLAN), a peer-to-peer (P2P) network, a mesh network, a cellular network, a Wireless Wide Area Network (WWAN), a navigation network (e.g., north american Global Positioning System (GPS) or another Global Navigation Satellite System (GNSS)), and/or a Wireless Personal Area Network (WPAN). In the context of the example environment 100, the wireless transceiver 138 enables the electronic device 102 to communicate with the base station 104 and a network to which the wireless transceiver is connected. However, the wireless transceiver 138 may enable the electronic device 102 to communicate with other devices or using alternative wireless networks.

The modem 136, such as a baseband modem, may be implemented as a system on a chip (SoC) that provides a digital communication interface for data, voice, messaging, and other applications of the electronic device 102. The modem 136 may also include baseband circuitry for performing high-speed sampling processes, which may include: analog-to-digital conversion (ADC), digital-to-analog conversion (DAC), gain correction, skew correction, frequency conversion, and the like. The modem 136 may also include logic to perform phase/quadrature (I/Q) operations, such as synthesis, encoding, modulation, demodulation, and decoding. Alternatively, the ADC or DAC operation may be performed by a separate component or another illustrated component, such as the wireless transceiver 138 shown.

The electronic device 102 also includes an audio system 122, the audio system 122 may be operably coupled to the display 120 and include: a component configured to vibrate the display 120 to produce an audio output (e.g., for a phone call or audio playback). The audio system 122 may be coupled to one or more of the signal processor 118 or the processor 108 and may include an audio amplifier 124, the audio amplifier 124 configured to receive one or more electrical audio signals and output an amplified electrical audio signal. The audio system 122 may include an actuator 126, the actuator 126 operatively coupled to the audio amplifier 124 and configured to receive the amplified electrical audio signal. In the present disclosure, although the actuator 126 is generally operatively coupled to the audio amplifier 124 and receives the amplified audio signal from the audio amplifier 124, the signal input to the actuator 126 may be referred to herein as an audio signal or an amplified audio signal (i.e., the actuator 126 is configured to receive some type of audio signal). Furthermore, an audio signal typically represents an electrical representation of an information signal intended to carry some type of audio content, such as voice information, and is not itself audible (e.g., an audio signal is a signal that is ultimately converted to an audible signal but may not be audible prior to conversion). The actuator 126 may be physically coupled to the display 120 and configured to vibrate the display 120 according to the audio signal content. In one aspect, the physical coupling may indicate that the actuator 126 is attached to the display 120 or at least physically coupled in a manner that causes the display 120 to vibrate. Based on the audio signal, the vibration of the actuator 126 and the physical coupling of the actuator 126 with the display 120 causes the display 120 to vibrate in a manner that produces sound (e.g., an acoustic output). As described above, in certain aspects, the vibration of the display 120 is of a type that generates sound waves in the air based on audible vibrations, and the user touching the electronic device 102 including the display 120 may or may not actually feel the vibration. The audio system 122 also includes a vibration sensor 130, the vibration sensor 130 configured to sense vibrations of the display and provide a vibration sensor signal accurately representative of the vibrations of the display 120 to provide feedback, as will be described further below. The audio system 122 also includes a microphone 132. The audio system 122 may also include an audio processor 134 (e.g., an audio codec) having hardware and/or other components configured to process inputs from the vibration sensor 130 and other audio components and provide converted digital or other signals to the processor 108 or signal processor 118 for further audio processing.

Fig. 2 is a block diagram of an example of an audio system 222 for using the display 220 as an audio emitter for the electronic device 102 (fig. 1). The audio system 222 includes a display 220. The display 220 is shown with multiple layers that together make up the display 220 to provide an example of how the multiple components/layers can be combined to form the display 220. The audio system 222 includes a processor 208 similar to the processor 108 described with reference to fig. 1. The processor 208 may include or be configured as a DSP. The processor 208 may also include other audio hardware processing components, such as an audio codec, for receiving input signals from audio-related I/O components and converting them into a form for processing by the processor 208. The audio system 222 also includes an audio amplifier 224, the audio amplifier 224 being operatively coupled to the processor 208 and configured to receive from the processor 208 an electrical audio signal to be output as an audio output. The audio amplifier 224 is configured to amplify and/or condition the electrical audio signal for provision to the audio output component. The audio amplifier 224 may also provide feedback to the processor 208, indicated by the double arrow regarding the connection between the processor 208 and the audio amplifier 224. There may be a feedback line from the output of the audio amplifier 224 to allow sensing of the amplified audio output from the audio amplifier 224, as shown by the dashed line. The feedback may be provided as a feedback signal to the audio amplifier 224 and/or the processor 208 for further conditioning the electrical audio signal.

The audio system 222 also includes an actuator 226 (e.g., a vibration actuator), the actuator 226 being operatively coupled to the audio amplifier 224 and configured to receive the amplified audio signal as an input audio signal. The actuator 226 is physically coupled to the display 220 (e.g., the back of the display 220) and is configured to cause the display 220 to vibrate according to the amplified audio signal from the audio amplifier 224. In one aspect, the physical coupling may indicate that the actuator 226 is attached to, or at least contacts, one or more components of the display 220 as follows: the vibration of the actuator 226 is transferred to one or more components of the display 220 to cause the display 220 to vibrate according to the amplified audio signal. In one aspect, the actuator 226 is an example of a means for causing the display 220 to vibrate.

As described above, in some aspects, other components or surfaces of the electronic device 102 can be coupled to the actuator 226 in addition to the display 220 to produce sound. However, the use of the display 220 may be common in view of the orientation of the display 220 relative to the user in most use cases, and the desire to expand the display area replacing other audio ports. The actuator 226 may include one or more of the following elements: the display 220 is caused to vibrate in response to an audio signal based on the mechanical coupling between the actuator 226 and one or more components of the display 220 (e.g., the actuator 226 receives as input an audio signal, where the audio signal is an amplified audio signal generated by the audio amplifier 224 based on an electrical audio signal from the processor 208). For example, the actuator 226 may have a mass (e.g., a metal plate or other resonator having a mass) configured to vibrate in accordance with an incoming electrical audio signal. The vibration of the mass of the actuator 226 is transferred to the display 220 based on the physical coupling of the actuator 226 to the display 220 and thereby causes the display 220 to vibrate. This may be in contrast to other sound emitters (e.g., cones or other membranes) that vibrate an element to cause vibration of air, rather than vibrating a physical component such as the display 220. The vibration of the display 220 is based on the audio signal, so the display 220 emits a sound (e.g., speech) in accordance with the audio signal (e.g., provided by the audio amplifier 224). The display 220 may thus be used to provide sound for voice calls or other audio playback. In certain aspects, the audio signal from the audio amplifier represents an audio speech signal, and the display 220 is configured to provide an acoustic output corresponding to the audio signal due to vibration of the display 220 due to the actuator 226. Other audible outputs besides audio speech signals are also contemplated.

As described above, it may be valuable to be able to generate a signal representative of the audio output of the audio system 222 in order to create a feedback loop for improving the quality of the audio output. In some systems using other types of audio transmitters (e.g., typical speakers), it may be difficult to obtain an accurate reference signal representative of the audio output of the audio system 222. Additional microphones may be provided to capture audio output. But in addition to capturing the output from the audio system 222, the additional microphones also pick up other background noise and other distortions. This background noise reduces the accuracy of the signal provided by the additional microphone, which itself is intended as an accurate representation of the audio output of the audio system 222. A feedback signal from the output of the audio amplifier 224 (and the input of the actuator 226) may also be used. However, the signal at the output of the audio amplifier 224 cannot include: the signal content resulting from the unique characteristics of the audio transmitter used, as well as various other distortions that may occur in the audio system 222 and affect the audio transmitter. Thus, the output of the audio amplifier 224 may not be a sufficiently accurate representation of the actual audio output of the audio emitter.

In particular, when using the display 220 as an audio transmitter, the particular physical characteristics of the display 220, and the manner in which the display 220 vibrates to generate an audio output, may cause the signal at the output of the audio amplifier 224 to be different from the signal representing the actual acoustic output (e.g., audio output) from the display 220 (e.g., the display 220 has a unique and different audio transfer function). In this case, the signal at the output of the audio amplifier 224 may not be accurate enough as a reference for quality feedback on the audio output of the display 220.

Fig. 3A is a block diagram of an example of an audio system 322 for using a display 320 as an audio emitter, the audio system 322 including a vibration sensor 330, according to certain aspects of the present disclosure. The audio system 322 includes a processor 308, an audio amplifier 324, and an actuator 326, which are configured similarly to that described above with respect to fig. 1 and 2. The audio system 322 also includes a vibration sensor 330. The vibration sensor 330 is physically coupled (e.g., mechanically coupled or attached) to the display 320 and is configured to sense vibrations of the display 320 due to the actuator 326 and output a vibration sensor signal proportional to the vibrations of the display 320 in response to the vibrations of the display 320 by the actuator 326. In one aspect, the physical coupling may indicate that the vibration sensor 330 is attached to or at least in mechanical contact with one or more components of the display 320. Because the vibration sensor 330 directly senses the vibration of the display 320 (e.g., vibrates with the display), the vibration sensor signal may be an accurate representation of the vibration of the display 320 in response to the audio signal. The vibration sensor signal is used in a feedback loop to provide further audio processing benefits and/or to improve the audio signal provided by the processor 308 (e.g., the vibration sensor signal captures the audio system output, which is then fed back to the processor 308 to generate an electrical audio signal to be output by the display 320, and the processor 308 may adjust the electrical audio signal input to the audio amplifier 324 based on the vibration sensor signal representing the audio or acoustic output of the audio system 322). The vibration sensor 330 is configured with a sensitivity that allows the vibration sensor signal to accurately represent the vibration of the display 320 over at least the speech spectrum (or a wider audio spectrum).

In one aspect, the vibration sensor 330 may be implemented as or include an accelerometer. Fig. 3B is a block diagram illustrating the accelerometer 330a as the vibration sensor 330 of fig. 3A. In certain aspects, the accelerometer 330a is a broadband accelerometer. For example, the accelerometer 330a may be a broadband accelerometer 330a having a bandwidth that spans at least frequencies within the voice range (e.g., up to 7kHz or more). The bandwidth of the accelerometer 330a used as the vibration sensor 330 may be significantly wider than accelerometers used for other purposes (e.g., device orientation sensors in the electronic device 102). Accelerometer 330a senses acceleration based on the vibration of display 320. In certain aspects, the accelerometer output may be an acceleration signal, also described more generally herein as a vibration sensor signal described herein for various types of vibration sensors. In certain aspects, the vibration sensor 330 (and accelerometer 330a) may be configured as a device for sensing vibrations of the display 320. Other sensors besides accelerometers may also be used or contemplated. For example, another type of piezoelectric sensor (e.g., ceramic piezoelectric sensor, etc.) or proximity probe may also be used.

Referring more generally to fig. 3A and 3B, the vibration sensor 330 (or accelerometer 330a) may be configured to convert the vibrations into an electrical vibration sensor signal that represents the vibrations of the display 320 (e.g., and corresponding to an audio frequency range) caused by the actuator 326. As one example, the vibration sensor 330, such as the accelerometer 330a, may employ piezoelectric properties or a spring/mass type element to generate an electrical vibration sensor signal. As described above, the vibration sensor 330 may be broadband compared to other vibration sensors used for other purposes (e.g., device orientation sensors, etc.). In this sense, the vibration sensor 330 may be configured and have a sensitivity to sense the following vibrations of the display 320: the vibrations have a frequency within a particular frequency range corresponding to the audio output (e.g., configured to sense vibrations within a large audio range, such as at least the speech range between 20Hz to 7kHz (with possibly a larger range)). The vibration sensor signal output may represent vibrations in this frequency range (e.g., in a large audio frequency range, such as in the voice range, for example) and have a sensitivity sufficient to provide information over the entire range to represent the audio output due to the particular physical vibration characteristics of the display 320.

The vibration sensor signal output from the vibration sensor 330 accurately represents a particular vibration of the display 320 (and a corresponding acoustic output (e.g., audio output) from the display 320). The vibration sensor signal may be used as an accurate reference signal provided to the processor 308. The processor 308 is configured to perform additional audio processing and/or conditioning of the electrical audio signal provided to the audio amplifier 324 based on the vibration sensor signal to improve the audio output or calibrate the audio output. In one example, the processor 308 is configured to adjust the audio signal provided to the actuator 326 (e.g., via the audio amplifier 324) based on the vibration sensor signal from the vibration sensor 330. In one example, the processor 308 is configured to adjust the audio signal to adjust or compensate for particular vibrations of the display 320 due to particular physical characteristics of the display 320 to better match the desired output. There are many ways of adjusting the audio signal. For example, the processor 308 may be configured to adjust the frequency response of the generated audio signal to be provided to the actuator 326 to provide an adjusted acoustic output from the display 320 due to vibration of the display 320 by the actuator 326. Alternatively or additionally, the magnitude level of the audio signal may be adjusted (e.g., may be frequency dependent) by the processor 308. In one aspect, because of the presence of the feedback loop, the audio signal represents a continuous signal that is continuously updated over time, such that there may be some negligible time period between: the audio signal is provided to the actuator 326 and when an update to the audio signal occurs based on the vibration sensor signal. In any case, the audio signal provided to the actuator 326 over a period of time is described herein as an audio signal that is adjusted based on the vibration sensor signal over the period of time. In one aspect, a method may include receiving a vibration sensor signal from a vibration sensor 330. The method may also include adjusting the audio signal provided to the actuator 326 based on the vibration sensor signal. Descriptions of various methods and/or operations are described in more detail below.

In certain aspects, the vibration sensor 330 may be positioned relative to the actuator 326 in an area where the magnitude of vibration of the display 320 is high. In one aspect, the vibration sensor 330 may be located close to the actuator 326 because the vibration of the display 320 may be higher in areas closer to the actuator 326. For example, with respect to proximity, in some cases, actuator 326 may be positioned on display 320 near where a user may be listening to the phone with their ear upright. In this case, the vibration sensor 330 may also be located in this area of the display 320. The vibration of the display 320 may be stronger in this area and increase the sensitivity of the output of the vibration sensor 330. However, it should be understood that the vibration sensor 330 may be positioned in other locations relative to the actuator 326 based on other factors (e.g., placement of other components, unique physical characteristics of the display that result in variations in vibration intensity, circuit board design considerations, wiring, etc.). For larger or complex systems, multiple vibration sensors may be provided, the outputs of which are combined into a single vibration sensor signal or used independently as different reference signals.

Fig. 4A is a block diagram of an example of an audio system 422 corresponding to the audio system 322 of fig. 3A, illustrating additional functional elements or components of the processor 408. In particular, the processor 408 may include a signal processor 418 (or in some cases, the processor 408 may correspond to the signal processor 418). The signal processor 418 is configured to provide an electrical audio signal to the actuator 426 (e.g., via the audio amplifier 424). The processor 408 also includes an audio codec 434 (e.g., corresponding to the audio processor 134 of fig. 1), which audio codec 434 may include one or more components configured to process inputs from one or more audio I/O devices (speakers, microphones, sensors, etc.) and provide them to the signal processor 418. The audio codec 434 may include, for example, an analog-to-digital converter circuit 435(ADC 435), the ADC 435 configured to receive the vibration sensor signal from the vibration sensor 430 and provide a digital output (e.g., a digital vibration sensor signal) to the signal processor 418 based on the analog signal provided by the vibration sensor 430. Although not shown, the processor 408 and/or the audio codec 434 may include interfaces (e.g., buses and other hardware) for formatting and transmitting digital signals between: between the ADC 435 or other elements of the audio codec 434 and the signal processor 418. Although the audio codec 434 is shown as part of the processor 408, it may be implemented with aspects of the processor 408, or it may be implemented as a separate chip. In addition, the vibration sensor 430 may have a digital output. Thus, ADC 435 may be optional or non-existent in certain implementations. This applies to the entire disclosure herein, where although ADC 435 is shown, if vibration sensor 430 or other device has a digital output, ADC 435 may not be present. Similarly, the signal processor 418 may be a discrete processor or may be part of the processor 408 (e.g., a different component, but integrated as a system on a chip). The signal processor 418 may perform additional processing on the vibration sensor signal provided to the signal processor 418 via the ADC 435. Additional processing may be used to correlate the vibration sensor signal with information about the audio output of the display 420 that is predetermined during testing or simulation. The correlation may be used to generate a corresponding audio signal based on the vibration sensor signal that is accurately indicative of the audio output of the display 420 and may be in a signal form that is more compatible with processing of the audio signal.

Fig. 4B is a block diagram of the audio system 422 of fig. 4A illustrating other examples of functional elements or components of the processor 408. In particular, the signal processor 418 includes additional functional elements or components to illustrate the following examples of processing circuitry and/or operations: where the vibration sensor signal from the vibration sensor 430 is processed and used in a feedback loop to adjust the electrical audio signal provided to the audio amplifier 424. While shown as a component of the signal processor 418, it is to be understood that one or more components may also be implemented in the audio codec 434 or generally in the processor 408. Although each block of the signal processor 418 is described as circuitry of the signal processor 418, it should be understood that the circuitry may represent any combination of hardware and/or software. In general, the processor 408 may be configured to perform the functions defined by each of the circuitry blocks.

The signal processor 418 includes acceleration-to-Sound Pressure Level (SPL) signal conversion circuitry 448 operably coupled to an output from the ADC 435. The acceleration-to-Sound Pressure Level (SPL) signal conversion circuitry 448 is configured to convert the vibration sensor signal (e.g., corresponding to a digital vibration sensor signal after conversion by the ADC 435 in some implementations) to a SPL signal. Based on predetermined information regarding how the measured SPL signal differs from the vibration sensor signal, the signal processor 418 applies a correlation function (or performs another correlation process) to the vibration sensor signal. The generated SPL signal more closely represents the audio signal as measured by the audio measurement device (e.g., determined in the sound chamber) and thus the audio signal is adjusted to correspond to an audio signal of a type similar to that provided to the actuator 426 (or at least more compatible or similar to the audio signal processed by the audio system 422).

For example, fig. 5A is a graph 550 illustrating a comparison between a vibration sensor signal from the vibration sensor 430 and a measured sound pressure level signal over a range of frequencies for different sound intensity levels (e.g., different volume levels). Dashed lines 552a and 552b represent acceleration frequency responses measured by the vibration sensor 430 for two different sound intensities (e.g., volume levels). Solid lines 554a and 554b show the respective frequency responses of the Sound Pressure Level (SPL) signals for two different sound intensities, as measured by the microphones in the sound chambers from the display 420. As shown, there is a high correlation between the vibration sensor signal response and the SPL signal response. Furthermore, the relationship is substantially linear. Based on information about the correlation between the vibration sensor signal response and the SPL signal response, a function or other information can be defined that is used to adjust the vibration sensor signal during operation to better match the corresponding SPL signal it represents. Accordingly, the processor 408 may be configured to convert the vibration sensor signal to an SPL signal (as shown by the acceleration-to-SPL signal conversion circuitry 448). In particular, the vibration sensor signal may be used to generate a corresponding SPL signal corresponding to the audio signal based on predetermined information regarding how different levels and/or different frequencies of the vibration sensor signal relate to the corresponding SPL signal.

The converted SPL signal is provided to SPL signal comparator circuitry 444, the SPL signal comparator circuitry 444 configured to compare the converted SPL signal to a target SPL model 446 (e.g., stored in a memory (not shown in fig. 4B, but shown in memory 110 of fig. 1)). The target SPL model 446 includes predetermined information for different frequencies/volumes that indicates desired sound output characteristics of the audio signal based on specific physical characteristics of the display 420. For example, the audio signal may be adjusted during testing to achieve high quality sound output from the display 220 (based on characteristics unique to the display 220). This test and/or simulation information may be used to generate a target SPL model 446, with the target SPL model 446 being stored and providing information about: how to adjust the converted SPL signal to better match the audio signal corresponding to the content desired to be output by the display 220. In one aspect, the processor 408 is configured to compare the SPL signal to a target SPL model 446 (as shown by SPL signal comparator circuitry 444) that represents audio output characteristics of the display 420. Providing an adjusted SPL signal that is adjusted for display sound characteristics based on operation of the SPL signal comparator circuitry 444.

The adjusted SPL signal is provided to frequency response correction circuitry 442, and the frequency response correction circuitry 442 is configured to receive the desired audio signal and to adjust the audio signal provided to the actuator 426 (e.g., via the audio amplifier 424) based on the desired audio signal and the adjusted SPL signal from the SPL signal comparator circuitry 444. The adjusted SPL signal represents a feedback signal or reference signal that represents the actual output of the display 420. This information may be used to compare to a desired input audio signal (e.g., generated based on incoming audio content from other external sources, such as from the other end of a voice call) to adjust the audio signal provided to the actuator 426 (e.g., via the audio amplifier 424) to improve sound quality. The frequency response correction circuitry 442 may be configured to adjust the input audio signal content at different frequencies based on distortion (as sensed in the adjusted SPL signal based on the vibration sensor signal) or other frequency-dependent characteristic. For example, the adjusted SPL signal may be used by the frequency response correction circuitry 442 to adjust the input audio signal across a frequency range to improve the final output (e.g., adjust the volume of certain frequencies, correct for harmonic distortion as indicated in the adjusted SPL signal, or correct for other distortion occurring in the adjusted SPL signal). Accordingly, in one aspect, the processor 408 may be configured to adjust the frequency response of the audio signal provided to the actuator 426 (e.g., via the audio amplifier 424) based on the comparison of the SPL signal to the target SPL model 446 (i.e., based on the adjusted SPL signal). Other examples of adjustments are provided below.

In some aspects, the adjusted SPL signal from SPL signal comparator circuitry 444 may be provided for some other audio processing function, such as for echo cancellation, instead of or in addition to being provided to frequency response correction circuitry 442, as described further below, to improve the overall audio system 422. Further, the processor 408 may be configured to adjust the audio signal provided to the actuator 426 (via the audio amplifier 424) based on any of the outputs of the elements shown in fig. 4B. For example, the processor 408 may adjust the audio signal directly based on the vibration sensor signal received from the ADC 435 without further processing or adjusting the audio signal based on the intermediate signal. In addition to the functions described with reference to fig. 4B, processor 408 may also perform other processing of the vibration sensor signal to further process the vibration sensor signal and derive therefrom audio characteristics of display 420.

As shown in graph 550, there is a high correlation between the measured SPL level and the measured vibration sensor signal output from the vibration sensor 430. This indicates that the vibration sensor signal may represent a high quality reference signal for use by the processor 408 in the feedback loop.

In addition, harmonic distortion (e.g., total harmonic distortion, THD) present in the audio signal provided to the actuator 426 or due to vibration of the display 420 may also be represented in the vibration sensor signal. In other words, the vibration sensor 430 captures the level of harmonic distortion present in the vibration of the display 420. In practice, the correlation between the measured THD and the THD in the vibration sensor signal may correlate well in the speech frequency range (e.g., up to about 4 kHz). The presence of THD in the vibration sensor signal may further provide a more accurate feedback signal for use by the processor 408 in a feedback loop.

There may also be delays (e.g., group delays) corresponding to the following times: the audio signal is output from the audio amplifier 424 to the display 420 to actually vibrate and produce sound. Because the vibration sensor 430 captures vibrations as the display 420 vibrates, the vibration sensor 430 also includes a delay in the vibration sensor signal. This may be further useful in providing an accurate feedback signal that allows the processor 408 to determine a delay and/or compensate for the delay during processing of the input audio signal based on the vibration sensor signal.

Furthermore, there may be some structural elements or other physical aspects of the electronic device 102 that interfere with or at least affect the vibration of the display 420. For example, there may be screws or other elements in contact with display 420 that slightly affect or alter the vibration of display 420. This type of distortion may be referred to as friction and buzz distortion. The vibration sensor 430 also captures friction and buzz distortion in the vibration sensor signal, as any effect on the vibration of the display 420 may also thereby affect the vibration of the vibration sensor 430. This may be further useful in providing an accurate feedback signal that allows the processor 408 to adjust the audio signal used to cause the display 420 to vibrate to generate an improved acoustic output from the display 420 (e.g., by providing the audio signal to the actuator via the audio amplifier in a manner that causes friction and buzz distortion to cancel when the display 420 vibrates).

Because the vibration sensor 430 may capture various distortion information, the vibration sensor 430 may provide a high-precision reference signal that accurately represents the actual audio output of the display 420 (e.g., as compared to the audio signal provided as input to the actuator 426). In one aspect, the vibration sensor signal differs from the audio signal at the input of the actuator 426 based at least on a transfer function that represents the vibration of the display in response to the audio signal. In another aspect, the vibration sensor signal is different from the audio signal at the input of the actuator 426 based at least in part on the physical dimensions or structural characteristics of the display 420. And the vibration sensor 430 may include distortion in common with distortion included in sound output by the display 420.

External force feedback loop

Referring to fig. 4A and 4B, the display 420 may be subjected to various external forces during operation. For example, a user's ear, hand, or other object pressing on display 420 may apply pressure (e.g., force) to display 420. At the time of the phone call, the user may place the phone (e.g., electronic device 102) on their ear to apply a force in the range of 2N to 8N. These forces may affect the vibration of the display 420, thereby changing the audio response of the audio system 422 and affecting the manner in which sound is generated by the display 420. In one aspect, the acoustic resistance may increase when a force is applied to the display 420. It may therefore be desirable to determine and/or estimate the amount of force applied to display 420 in order to adjust the audio signal to potentially improve audio quality or compensate for the force applied to display 420. There is no effect on the sound output due to the force at the output of the audio amplifier 424, so a more accurate reference signal is required.

As shown in fig. 4A and 4B, vibration sensor 430 is configured to form part of a feedback loop that provides a vibration sensor signal representative of the vibration of display 420, and may be used to estimate the amount of force applied to display 420 (e.g., an estimate of the amount of force applied to display 420 by something other than actuator 426). In one aspect, the processor 408 is configured to compare how the vibration pattern changes based on analyzing the vibration sensor signal from the vibration sensor 430, and to adjust the audio signal provided to the actuator 426 (e.g., via the audio amplifier 424) based on how the pattern changes. More generally, the processor 408 is configured to adjust the audio signal based on the vibration sensor signal from the vibration sensor 430. In one aspect, the processor 408 is an example of a means for adjusting an audio signal based on a vibration sensor signal. The processor 408 may be configured to adjust the audio signal in response to a force applied to the display 420 that affects the vibration of the display 420. In one aspect, the processor 408 is configured to determine an estimate of the level of force applied to the display 420 based on the vibration sensor signal from the vibration sensor 430. The processor 408 is then configured to adjust an audio signal (a force applied by something other than the actuator 426) applied to the actuator 426 (e.g., via the audio amplifier 424) based on the estimate of the level of the force. In some aspects, the processor 408 is an example of a means for determining an estimate of the level of force.

In one aspect, if a force is applied to the display 420 (effectively suppressing vibration and thus sound output), the processor 408 may be configured to enhance the audio signal as a result. For example, the processor 408 may be configured to increase the size (e.g., intensity level) of the audio signal based on the estimate of the level of force. In some aspects, increasing the size (or decreasing the size) may correspond to increasing (or decreasing) the volume level of the audio signal. In some scenarios, the processor 408 may also reduce the amplitude (e.g., magnitude) of the audio signal in response to estimating the level of force (e.g., when the force is removed or, for example, the ears may be close enough to more easily hear the audio output, thus possibly requiring balancing or lowering the volume).

The influence of the force may be frequency dependent, with some frequencies of the audio output being more influenced by the force than others. Thus, the processor 408 may be configured to estimate the force across different frequencies. Based on this information, the processor 408 may be configured to adjust the amplitude or other characteristics of the audio signal for different frequencies to improve audio quality.

To estimate the force, the processor 408 may be configured to compare the vibration sensor signal to an expected reference signal (e.g., a signal representative of no applied force) and determine an estimate of the level of force based on the comparison (e.g., compare to a threshold and determine the level of force based on a relative magnitude difference from the threshold). Based on the difference between the vibration sensor signal and the expected reference signal, the processor 408 is configured to adjust the audio signal applied to the actuator 426 (e.g., via the audio amplifier 424) based on the comparison.

Processor 408 may estimate the force over a certain period of time, such as 10 samples per second (as but one example), and adjust the output as the force is applied or removed.

Fig. 5B is a diagram 500 illustrating a representation of an audio signal across frequencies based on different forces applied to the display 420. The y-axis represents the amplitude of the signal across different frequencies (x-axis). Similar to the curve 550 of fig. 5A, the dashed line represents the amplitude of the vibration sensor signal from the vibration sensor 430 at different frequencies, while the solid line represents the corresponding SPL signal measurement output. Each set of lines in graph 500 (e.g., where one set is a dashed and solid line pair) may represent a different force. Graph 500 shows the response to a 5N force applied to display 420 for two different volume levels (e.g., the top line at one volume level and the bottom line at different volume levels) compared to a force not applied to display 420. As shown, the amplitude varies based on force, and some frequencies are affected more than others. The processor 408 is configured to estimate the level of force based on the vibration sensor signal and adjust the audio output when generating an audio signal for application to the display 420 by the actuator 426 to compensate for or otherwise account for the force. This enables a high sound quality in different scenarios and environments, e.g. and when making voice calls.

Further, a point may be reached where there is sufficient force such that the display 420 may be difficult to vibrate (e.g., a saturation condition). This situation may be frequency dependent, where for certain forces at particular frequencies, the ability of display 420 to vibrate at those frequencies may be diminished. For example, a protective case/cover may be added to the electronic device, which may affect how the display 420 vibrates. The force from the shell or otherwise may be estimated by the processor 408 based on the vibration sensor signal from the vibration sensor 430, and the processor 408 is configured to adjust the audio signal based on the information about the force and how it changes due to the force frequency response.

The processor 408 may be configured to estimate the force level using any of the elements of the signal processor 418 described with reference to fig. 4B. For example, the processor 408 may be configured to determine an estimate of the level of force directly based on the vibration sensor signal from the ADC 435, or may determine an estimate of the level of force based on the SPL signal provided by the acceleration to the SPL signal conversion circuitry 448 or the adjusted SPL signal provided by the SPL signal comparator circuitry 444.

It should be understood that estimating the force level may be one of many examples of how the audio system 422 improves the audio signal that drives and vibrates the display 420. Indeed, the vibration sensor signal may be used in a variety of ways to condition the audio signal. In this case, typically, the vibration sensor signal is dynamically used in real-time to continuously provide information about how the display 420 is sounding and to allow the processor 408 to continuously (or at least periodically) adjust the audio signal based on this information to improve the quality of the sound output and/or to adjust desired audio output characteristics. Thus, the volume level, frequency response characteristics, and other audio parameters may be adjusted based on the reference vibration sensor signal. For example, distortion present in the audio output of the display 420 may be sensed via the vibration sensor signal and then compensated for, such that the adjusted audio signal provided to the actuator 426 causes vibration of the display 420 in a manner that reduces the distortion. Thus, the processor 408 is configured to adjust the audio signal based on the vibration sensor signal from the vibration sensor 430 as part of a closed loop feedback system. In some aspects, the vibration sensor signal may also be provided to an audio amplifier 424. In this case, the audio amplifier 424 adjusts the output of the audio amplifier 424 based on the vibration sensor signal from the vibration sensor 430. In various aspects, in such implementations, the audio amplifier 424 may receive the vibration sensor signal from the vibration sensor 430 or the vibration sensor signal as a digital signal from the audio codec 434. This may replace or supplement the conditioning of the electrical audio signal provided as input to the audio amplifier 424 by the processor 408. Thus, in addition to the dashed line showing the feedback path from the output of the audio amplifier 424 to the audio amplifier 424, there may be another optional connection between the vibration sensor 430 (or from the audio codec 434) to provide a vibration sensor signal (or in digital form) to the audio amplifier 424 other than the signal processor 418.

In one aspect, a method may include estimating a force level applied to the display 420 based on a vibration sensor signal from the vibration sensor 430. The method may further include adjusting the audio signal applied to the actuator 426 based on the estimated force level.

Q factor tracking

The resonant frequency Q-factor value of the electromechanical system including the actuator 426 and the display 420 may also be affected by an external force (e.g., pressure) applied to the display 420 (e.g., due to a user's hand or a user's ear). Electromechanical systems may have a high Q factor, enabling the generation of vibrations with sufficient intensity to achieve better sound quality and the ability to achieve sufficient volume. A high Q factor results in a large offset value at the resonant frequency (where the offset indicates the degree of amplitude of the physical motion of the mass within the actuator 426). The change in the Q factor may be indicative of a change in the shift value around resonance. Tracking the Q factor may allow for preventing excessive excursions to prevent damage to the actuator or allow the processor 408 to adjust the audio signal applied to the actuator 426 based on changes in the Q factor.

The vibration sensor signal from the vibration sensor 430 may be used to determine an estimate of the change in Q-factor of the electromechanical system including the actuator 426 and the display 420 due to the external force. Due to the high Q factor, and because electromechanical systems may typically have a single or dominant resonant frequency, the frequency range of the signal to be analyzed to determine the Q factor may be narrow (e.g., relative to the frequency range of the entire audio signal).

FIG. 6 is a graph 600 illustrating the change in Q-factor of an electromechanical system including actuator 426 and display 420 due to different external forces applied to display 420. Each line represents an audio signal with a different force applied to the display 420. The region identified by the arrows in the figure shows the region around the resonant frequency of the system (e.g., as an example, a peak centered at 190 Hz). In this region, the "sharpness" of the peak at the resonant frequency may correspond to the Q factor, while sharper peaks correspond to higher Q factors. As shown, the Q factor changes significantly with different force levels applied to the display 420. The processor 408 may be configured to determine the estimated Q-factor by analyzing the vibration sensor signal near the resonant frequency of the electromechanical system and estimating the Q-factor. The processor 408 may be configured to determine a change in the Q-factor based on the vibration sensor signal (based on the estimated Q-factor) and adjust the audio signal provided to the actuator 426 (e.g., via the audio amplifier 424) based on the change in the Q-factor. Because the resonant frequency is centered on a smaller range, the processor 408 may be configured to evaluate the vibration sensor signal over a range of frequencies that includes the resonant frequency of the electromechanical system. The frequency range may be smaller than a speech frequency range of the audio signal. In this case, the processor 408 may be configured to determine the change in the quality factor based on an evaluation of a narrower frequency range around the resonant frequency.

Processor 408 may determine the Q factor using the following equation (where Fs represents the resonant frequency, Mms represents the moving mass, Cms represents the compliance, Rms represents the mechanical resistance, and Qms represents the mechanical Q factor of the actuator at the resonant frequency):

however, the processor 408 may use other equations or operations to determine an estimate of the Q factor or track how the Q factor changes.

In certain aspects, to measure Q factor values, the vibration sensor 430 (e.g., an accelerometer) may have a reduced bandwidth (e.g., analyze the signal over a smaller frequency range near resonance) in this case compared to certain other implementations. Thus, in some aspects, a lower cost vibration sensor 430 may be used for this Q-factor technique.

The variation in the Q factor may provide a more course estimate of the external force level (than estimating the force level over the entire audio spectrum). In addition, there may be other uses for detecting the force applied to the display 420 (either based on the Q-factor method or based on analyzing the full spectrum). For example, additionally, processor 408 may use information from vibration sensor 430 to detect a force to perform proximity detection and then trigger a different device action (e.g., turn off display 420 when a force is detected during a call, or alternatively turn on display 420 when a force is detected to be removed, or activate a speakerphone if a force is removed). Accordingly, the processor 408 may be configured to perform an action or change an electronic device display setting (or other electronic device setting) based on the vibration sensor signal. Information from vibration sensor 430 can be used to identify the Q factor and to adjust the deflection control block (deflection again refers to the amount of mass movement in actuator 426 that causes actuator 426 to vibrate display 420). This may allow to reduce the risk of excessive offset or to avoid reducing unwanted offsets. Furthermore, having accurate offset information may allow the processor 408 to improve sound quality and increase loudness.

In one aspect, a method may include estimating a Q factor value of the actuator 426 based on a vibration sensor signal from the vibration sensor 430. The method may further include adjusting the audio signal applied to the actuator 426 based on the estimated Q factor value.

Echo cancellation

In many audio systems, in addition to capturing sound from the user's voice as desired, the microphone may capture/sense sound from a speaker of the electronic device 102, including a microphone that produces an echo path. For example, at one end of a telephone conversation, the sound of someone speaking on a first device is output by a speaker of a second device. This audio is picked up by a microphone at the second device and then unintentionally transmitted back to a speaker at the first device, resulting in an echo path. To address this issue, a reference signal (e.g., echo reference) is required to allow for cancellation or suppression of the echo signal received by the microphone, the reference signal being limited to sound intended to be output by the speaker at the second device.

Fig. 7 is a block diagram of an example of an audio system 722 using a display 720 as an audio emitter, the audio system 722 including a vibration sensor 730 and echo cancellation according to certain aspects of the present disclosure. The audio system 722 of fig. 7 includes the elements of the audio system 422 of fig. 4A, and also includes a microphone 732. The audio codec 734 includes an ADC 735b (except for ADC 735a, which corresponds to ADC 435 of fig. 4A). The ADC 735b is operatively coupled to the microphone 732 and provides a digital representation of the microphone signal received via the microphone 732 to the signal processor 718 (e.g., the processor 708). As described above with respect to fig. 4, if the output from the microphone 732 is digital, the ADC 735b may not be present. The audio codec 734 may be configured to further process signals received via the microphone 732.

As shown in fig. 7, sound emitted by the display 720 may be received by a voice microphone 732 (although in fact in most cases the microphone 732 is intended to capture other externally generated sound, such as the user's voice). As described above, because the microphone 732 may transmit content it receives to the user at the other end of the call, an echo (e.g., echo path) of what the user said may be received at the other end of the call. As such, it is desirable that the echo signals received by the voice microphone 732 be cancelled (or at least substantially suppressed). As described above, the transfer function based on the vibration of the display 720 may be quite different from the output of the audio amplifier 724, resulting in the actual display audio output signal being different from the output signal of the audio amplifier 724. Thus, the output signal of the audio amplifier 724 may not be a sufficiently accurate representation of the display acoustic output used to cancel the echo signal from the signal captured by the microphone 732.

The audio system 722 includes a vibration sensor 730 that provides a vibration sensor signal that accurately represents the acoustic output of the display 720 due to vibration of the display 720 by the actuator 726, as described above. The vibration sensor signal provides an accurate echo reference at least in part because the vibration sensor 730 is able to account for a transfer function that represents the vibration of the display 720 and the actuator 726. The echo reference signal is used to cancel the echo signal received via the microphone 732.

To provide echo cancellation, the processor 708 is configured to generate an echo reference signal based on the vibration sensor signal from the vibration sensor 730. The echo reference signal corresponds to: a representation of an acoustic output (e.g., an audio output) resulting from vibration of the display 720 due to vibration of the display. As described herein, the acoustic output from the display 720 may be different from the audio signal from the audio amplifier 724 input to the actuator 726 based on the unique physical characteristics of the display. The processor 708 is configured to cancel or suppress at least a portion of an echo signal included within the microphone input signal received at the microphone 732. The processor 708 is configured to cancel or suppress at least a portion of the echo signal based on an echo reference signal, which is generated based on the vibration sensor signal from the vibration sensor 730. The echo signals represent the acoustic output (e.g., audio output) of the display 720 captured by the microphone 732. Echo cancellation may be activated during a voice call or other playback mode to cancel echo. In one aspect, the processor 708 may be an example of a means for generating an echo reference signal and a means for canceling at least a portion of the echo signal. The signal output from the audio amplifier 724 may also be used in conjunction with the vibration sensor signal as part of echo cancellation. In this case, the processor 708 is configured to cancel the echo signal also based on the signal from the output of the audio amplifier 724. Further, more generally, the processor 708 may be configured to: the microphone output signal output from the microphone 732 is adjusted based on the vibration sensor signal (e.g., to remove or suppress from the microphone output signal any signal content included in the microphone output signal due to the capture of sound output by the microphone 732).

Although not shown, processor 708 and signal processor 718 may include one or more components shown in fig. 4B to process the vibration sensor signals for echo cancellation or other purposes. Accordingly, to generate the echo reference signal from the vibration sensor signal, the processor 408 may be configured to perform any of the functions described above with respect to the elements of the signal processor 418 of fig. 4B (e.g., SPL signal conversion, etc.). However, in some cases, the output from the frequency response correction circuitry 442, or from other circuitry, may be used by the processor 708 to cancel echo signals within the microphone input signal for echo cancellation purposes, rather than to adjust the audio signal provided to the actuator 726 (e.g., via the audio amplifier 724). More generally, note that for echo cancellation purposes, in some implementations, it may not be necessary to adjust the audio signal provided to the actuator 726 (e.g., via the audio amplifier 724) based on the vibration sensor signal. The processor 708 may be configured to cancel echo signals in the microphone output signal captured by the microphone 732 for echo cancellation purposes, although the audio signal input to the actuator 726 may be conditioned for other purposes. The modified microphone output signal is then transmitted to another remote device (echo cancelled) via transceiver 138 (fig. 1). Accordingly, the processor 708 may include circuitry or functionality configured to cancel echo signals and otherwise process microphone output signals for transmission or for other uses of the microphone input signals (e.g., voice assistant, etc.). It should be noted, however, that the adjustment of the audio signal provided to the actuator 726 based on the vibration sensor signal and echo cancellation for tonal purposes may be performed in accordance with implementations described herein.

As described with reference to fig. 7, the use of the vibration sensor 730 may be particularly advantageous for echo cancellation in the audio system 722. In particular, the entire display 720 vibrates and produces sound. Due to the size of the display 720, the microphone 732 may always be close to vibrating (such as at the opposite end of the device as compared to when using a microphone 732 that is relatively far from the speaker), regardless of the location of the microphone 732. Thus, when using the display 720 as a sound emitter, the distance between the display 720 and the microphone 732 is small, allowing sound to attenuate before reaching the microphone 732. Thus, it may be desirable to generate a more accurate echo reference signal (e.g., by vibration sensor 730). In addition, as described above with reference to fig. 4A and 4B, the vibration sensor 730 may be able to accurately capture harmonic distortion, group delay, friction, and hum distortion, among others. This is particularly valuable during echo cancellation, since at least some of the distortion captured by vibration sensor 730 may also be captured by microphone 732 when microphone 732 captures sound emitted by display 720. For example, the microphones 732 may have a group delay, as described above. Because the vibration sensor signal also includes a group delay, it may be easier to align the echo signal in the microphone signal with an echo reference signal generated from the vibration sensor signal for cancellation purposes. Also, harmonic distortion or friction and buzz distortion captured by the vibration sensor 730 may be matched to the distortion captured by the microphone 732 and used for cancellation purposes. Thus, the echo reference signal based on the vibration sensor signal may include harmonic distortion, group delay, friction and buzz distortion, etc. (which may correspond to similar distortion, group delay, etc. also picked up by the microphone 732).

Further, some systems may use additional microphones to receive and generate representations of the echo signals. However, any such microphone may pick up background noise or other unwanted audio content, and therefore such content includes more signal content than echo and will not be a clean reference signal. Using a reference signal from such an additional microphone, which may include background noise, may result in canceling echo signals that are not merely in the microphone output signal, thereby cutting off portions of the intended signal to be transmitted. In contrast, vibration sensor 730 generates a signal with reference to the vibration of display 720 and does not pick up other background noise (as other external audio noise is typically not sufficient to vibrate display 720). This results in a strong and clean echo reference signal from the vibration sensor 730. As described above, the vibration sensor 730 is broadband in that it can represent vibrations within an audio range (e.g., for speech) to allow for the generation of a reference signal. It should be understood that in some cases, other sensors (e.g., microphones) may be used to generate a portion of the echo reference signal, thereby combining the vibration sensor signal with other inputs (including the output from the audio amplifier) to generate the echo reference signal.

In some aspects, the vibration sensor 730 is located slightly separate from the actuator 726 (i.e., not physically coupled to the actuator 726) such that the vibration sensor signal represents the vibration of the display 720 (due to the unique transfer function of the display 720 as compared to the actuator 726 alone). However, as described above, the vibration sensor 730 may be located in the same vicinity as the actuator 726, so that the vibrations are not overly attenuated when they reach the vibration sensor 730.

In one aspect, a method may include receiving a vibration sensor signal from a vibration sensor 730 physically coupled to a display 720. The method may further include generating an echo reference signal based on the vibration sensor signal. The method may also include receiving a microphone audio signal from a microphone 732. The method may further include canceling the echo signal from the microphone audio signal based on the echo reference signal.

Multi-surface acoustic emission

Referring to fig. 4A and 4B, because the display 420 is mechanically coupled to the back plate and other portions of the phone, the back plate and other portions of the electronic device may be subject to vibration in response to vibration of the display 420 by the actuator 426. The vibration of the back plate may cause the back plate or the side plates to emit sound. This may be undesirable because other users may be able to hear sound from the back panel when approaching a voice call, or generally do not want sound emitted by parts other than the display 420.

Fig. 8A is a block diagram of an example of an audio system 822a using a display 820 as an audio emitter, the audio system 822a including a vibration sensor 830a, according to certain aspects of the present disclosure. Audio system 822a shows a backplane 850 with some mechanical coupling to display 820. The backplate 850 may thus vibrate in response to the vibration of the display 820 by the first actuator 826a, resulting in sound being emitted from the backplate 850. To prevent sound from being emitted from the backplate 850, the audio system 822a may counteract vibrations of the backplate 850. The audio system 822a includes elements as described with reference to fig. 4A, including a first actuator 826a (corresponding to actuator 426), a first audio amplifier 824A (corresponding to audio amplifier 424), and a vibration sensor 830 (corresponding to vibration sensor 430). The audio system 822a also includes a processor 808, which processor 808 may have a signal processor 818 and an audio codec 834, similar to that described above (with ADC835 a).

The audio system 822a also includes a second actuator 826b physically coupled to the backplate 850. Although shown as a backplate 850, it should be understood that the backplate 850 may be representative of any other surface or component having mechanical coupling to the display 820 that vibrates in response to vibration of the display 820 by the first actuator 826a (e.g., the second actuator 826b may be physically coupled to a portion of the electronic device that is in a different location than the first actuator 826a is physically coupled). The audio system 822a also includes a second audio amplifier 824b, the second audio amplifier 824b operatively coupled to a second actuator 826b and configured to: the second audio signal is amplified (e.g., a second amplified electrical audio signal is provided) and provided as an input to the second actuator 826 b. The second audio amplifier 824b is also operatively coupled to the processor 808 and configured to amplify and/or condition an electrical audio signal from the processor 808 (e.g., from the signal processor 818). The second audio amplifier 824b may also provide feedback to the processor 808, indicated by the double arrow on the connection between the processor 808 and the second audio amplifier 824b, the dashed line showing the feedback path that may be provided to the processor 808: from the output of the second audio amplifier 824b to the second audio amplifier 824 b. For example, there may be a feedback line from the output of the second audio amplifier 824b to allow sensing of the amplified audio output from the second audio amplifier 824 b. The feedback may be provided to the processor 808 in a feedback signal to further condition the second electrical audio signal. In some implementations, the circuitry may be shared between the first audio amplifier 824a and the second audio amplifier 824b, or they may form a signal audio amplifier circuit configured to provide a first audio signal to be provided to the first actuator 826a and a second audio signal to be provided to the second actuator 826 b.

A second actuator 826b may be provided to vibrate the backplate 850 in a manner that cancels the vibrations caused by the display 820. More generally, the processor 808 is configured to provide an audio signal to the actuator 826b (e.g., via the second audio amplifier 824b) based on the vibration sensor signal from the vibration sensor 830. In one aspect, the processor 808 is configured to generate a second audio signal that is provided to the actuator 826b (e.g., via the second audio amplifier 824b), wherein the second audio signal is generated to have a waveform that cancels the vibration of the backplate 850 caused by the vibration of the display 820. In one aspect, the second audio signal sensor 830 is generated based in part on a vibration sensor signal from vibrations.

In one aspect, the processor 808 applies the second audio signal to the second actuator 826b at the same amplitude and frequency as the displacement sensed by the vibration sensor signal from the vibration sensor 830, but with a 180 degree phase relative to the vibration sensor signal. More generally, the processor 808 is configured to generate a second audio signal having a waveform that is out of phase with a signal generated based on the vibration sensor signal. Eliminating the vibrations in the backplate 850 reduces the vibrations of the backplate 850 and reduces any leakage sound or may generally prevent the backplate 850 from emitting sound (or at least substantially dampen sound).

Fig. 8B is a block diagram of the audio system 822a of fig. 8A, showing other examples of functional elements or components of the processor 808. In particular, the audio system 822B of fig. 8B includes additional components similar to those described with reference to fig. 4B that are shown as part of the signal processor 818. In particular, signal processor 818 of fig. 8B includes acceleration-to-SPL signal conversion circuitry 848, SPL signal comparator circuitry 844, target display SPL model 846, and frequency response correction circuitry 842, which may operate similarly with respect to the corresponding circuitry described with reference to fig. 4B. The resulting signal output by the frequency response correction circuitry 842 may correspond to an audio signal provided to the actuator 826a (via the first audio amplifier 824a) for vibrating the display 820 after correcting various distortions and the like using a feedback path based on the vibration sensor signal as described above.

The output of the frequency response correction circuitry 842 may also be provided to response and phase adjustment circuitry 852, the response and phase adjustment circuitry 852 being configured to apply a signal to the actuator 826b (e.g., via the second audio amplifier 824b) to cause vibration of the backplate 850 via the second actuator 826 b. The response and phase adjustment circuitry 852 receives the audio signal from the frequency response correction circuitry 842 and is configured to adjust the phase of the second audio signal (e.g., relative to the phase of the audio signal from the frequency response correction circuitry 842) to cause the second actuator 826b to vibrate the backplate 850 to cancel vibrations in the backplate 850 that would otherwise be caused by the vibration of the display 820. In some aspects, the response and phase adjustment circuitry 852 is configured to adjust the phase of the second audio signal to be out of phase with the input audio signal from the frequency response correction circuitry 842 such that the vibrations of the backplate 850 result in a net cancellation (or substantial cancellation or significant suppression).

The backplate 850 may have certain characteristics that cause the backplate 850 to output sound in a unique manner and distinct from the display 820. Thus, a target backplane SPL model 854 can be provided in memory, similar to the target display SPL model 446 described with reference to fig. 4B, the target backplane SPL model 854 representing audio characteristics unique to the backplane 850. 4B. The response and phase adjustment circuitry 852 may be configured to receive an input from the target backplate SPL model 854 and adjust the second audio signal based on the target backplate SPL model 854 to generate a second audio signal for vibrating the backplate 850. The second audio signal is adjusted to provide better cancellation, such as for the audio characteristics of the backplate 850. Similar to that described with reference to fig. 4B, one or more of the components shown in the signal processor 818 may instead be implemented or included in the audio codec 834. At least a portion of the processor 808 may include one or more components of the signal processor 818 or the audio codec 834.

Fig. 8C is a block diagram of another example of an audio system 822C using a display 820 as an audio emitter, the audio system 822C including two vibration sensors 830a and 830b for sound leakage cancellation, according to certain aspects of the present disclosure. The audio system 822c includes the elements of the audio system 822a of fig. 8A, and further includes a second vibration sensor 830b, the second vibration sensor 830b physically coupled to the backplate 850 and configured to output a second vibration sensor signal representative of the vibration of the backplate 850. The second vibration sensor 830b may be configured to provide a second vibration sensor signal to a second ADC 835b of the audio codec 834. The second ADC 835b may be configured to provide a digital signal representative of the second vibration sensor signal to the processor 808. It may be beneficial to obtain additional information about how the backplate 850 vibrates in particular. In particular, the audio system 822a of fig. 8A may estimate the vibration of the backplate 850 based on knowledge of the audio signal provided to vibrate the display 820 and also based on information about how the backplate 850 vibrates during one or more tests (e.g., stored in the target backplate SPL model 854, as described with reference to fig. 8B). However, in some implementations, a second vibration sensor 830b may be included to determine how specifically the backplate 850 vibrates during operation based on the varying degree of mechanical coupling between the devices to the display 820. The unique vibration pattern of the backplate 850 may be sensed by the second vibration sensor 830b to more accurately determine a specific vibration signal at the backplate 850, thereby enabling the elimination of vibrations of the backplate 850.

The processor 808 is configured to: the second vibration sensor signal from the second vibration sensor 830b as part of the feedback loop is used to generate an audio signal to provide to the actuator 826b (e.g., via the second audio amplifier 824b), which causes vibration of the backplate 850 via the second actuator 826b, which cancels the vibration of the backplate 850. More generally, the processor 808 is configured to adjust the second audio signal provided to the actuator 826b based on the second vibration sensor signal from the second vibration sensor 830b (e.g., via the second audio amplifier 824 b). Further, the processor 808 may be configured to adjust the second audio signal based on a combination of the vibration sensor signal from the first vibration sensor 830a and the second vibration sensor signal from the second vibration sensor 830b (e.g., adjust a frequency response, a magnitude, etc. of the second audio signal).

Fig. 8D is a block diagram of the audio system 822C of fig. 8C. Other examples of functional elements or components of the processor 808 are shown. The audio system 822D of fig. 8D includes the elements of the audio system 822B of fig. 8B, along with the second vibration sensor 830B (and second ADC835B) of fig. 8C. The signal processor 818 (labeled without a box to avoid visual confusion) of the audio system 822d includes additional components for processing the second vibration sensor signal. In addition to the components described with respect to the audio system 822B of fig. 8B (shown as acceleration-to-SPL signal conversion 848a, SPL signal comparator circuitry 844a, and target display SPL model 846a), the signal processor 818 of fig. 8D includes acceleration-to-SPL signal conversion circuitry 848B, the acceleration-to-SPL signal conversion circuitry 848B configured to convert the second vibration sensor signal to a second SPL signal based on similar correlations as described above with respect to the corresponding circuitry of fig. 4B. The second SPL signal from acceleration to SPL signal conversion circuitry 848b is provided to SPL signal comparator circuitry 844 b. Similar to that described with reference to the corresponding blocks of fig. 4B, the SPL signal comparator circuitry 844B is configured to compare the second SPL signal to the target backplate SPL model 854 to generate an adjusted second SPL signal that is adjusted based on the audio output characteristics of the backplate 850. The adjusted second SPL signal is provided to response and phase adjustment circuitry 852. In addition to the adjusted second SPL signal, which represents the audio signal output from backplane 850, response and phase adjustment circuitry 852 also receives the audio signal generated for display 820 (e.g., as output by frequency response correction circuitry 842). The response and phase adjustment circuitry 852 is configured to generate an adjusted second audio signal (e.g., out of phase) based on both the audio signal from the frequency response correction circuitry 842 and the adjusted second SPL signal. In one aspect, the second audio signal is generated to have a waveform that cancels vibrations of the backplate 850 due to mechanical coupling with the display 820.

In some cases, there may be more than one display, or indeed it may be desirable to emit sound from the backplate 850 (or other portion of the electronic device). Thus, rather than canceling sound, the audio system 822d can be configured to simply provide sound via two displays or align audio output using feedback from the vibration sensors 830a and 830 b. For example, the processor 808 may be configured to provide a second audio signal to the actuator 826b (e.g., via the second audio amplifier 824b) that is in phase with a signal based on the first vibration sensor signal of the first vibration sensor 830a physically coupled to the display 820. In another aspect, the processor 808 may be configured to provide a second audio signal to the actuator 826b (e.g., via a second audio amplifier 824b) that aligns the vibrations of each of the display 820 and the other component with one another. As another example, because the displays may have different physical characteristics, they may have different audio responses (different transfer functions). Thus, it may be useful to use the vibration sensors 830a and 830b to provide feedback, and then the processor 808 may adjust the audio signals of both actuators 826a and 826b to compensate or adjust the different audio responses to improve overall sound quality (or allow for structural additions to the sound). Fig. 9 shows an example of the audio system 822C of fig. 8C, but with the back panel replaced with a second display 920 b. The audio system 922 of fig. 9 includes the elements of fig. 8C (including the second vibration sensor 930b), but includes the first display 920a and the second display 920 b. In other implementations, the second display 920b may be a backplane or other panel or externally facing surface. Any of the blocks or components in fig. 8A, 8B, 8C, and 8D may be used in the audio system 922 of fig. 9. In the case of the audio system 922 of fig. 9, however, the processor 908 is configured to provide a second audio signal to the actuator 926b via the second audio amplifier in a manner that intentionally generates sound via the second display 920b based on vibration of the second display 920b by the second actuator 926 b. Further, each of the first vibration sensor signal from the first vibration sensor 930a and the second vibration sensor signal from the second vibration sensor 930b may be used by the processor 908 as feedback signals for adjusting one or more of a first audio signal to be applied to the first actuator 926a via the first audio amplifier 924a and a second audio signal to be applied to the second actuator 926b via the second audio amplifier 924 b.

In one aspect, a method may include generating a vibration sensor signal representing vibration of a component (e.g., the backplate 850) mechanically coupled to the display 820 that vibrates in response to the first actuator 826 a. The method may include vibrating the component based on the vibration sensor signal to cancel vibration of the component caused by mechanical coupling to the display 820.

Fig. 10 shows an example of an audio system 1022 similar to fig. 3A, but with the display replaced with a generic component. Thus, other components may replace the display and emit sound. By way of example, any externally facing surface or component may be selected as the sound emitter based on the principles described herein.

In general, an audio system may include an array of actuators, where each actuator is configured to cause vibration of a different portion of an electronic device in response to a respective audio signal. The audio system in this case may further comprise an array of vibration sensors, wherein each vibration sensor is configured to output a respective vibration sensor signal proportional to the vibration of a different part of the electronic device.

Example operations

Fig. 11 is a flow diagram illustrating an example of a method 1100 for generating audio using the display 420 with reference to fig. 4A and 4B. The method 1100 is described in terms of a set of blocks that specify operations that can be performed. However, the operations are not necessarily limited to the order shown in FIG. 11 or described herein, and the operations may be performed in an alternate order or in a fully or partially overlapping manner. Moreover, more, fewer, and/or different operations may be implemented to perform the method 1100 or alternative methods. At block 1102, the method 1100 includes: the display 420 is vibrated using an actuator 426 that is physically coupled to the display 520 based on an audio signal provided as an input to the actuator 426 and generated by an audio amplifier. At block 1104, the method includes: the vibration sensor signal is generated using a vibration sensor 430 physically coupled to the display 420. The vibration sensor signal is proportional to the vibration of the display 420 that is generated in response to the vibration of the display 420 by the actuator 426.

In one aspect, at block 1106, the method 1100 may further include adjusting an audio signal provided to the actuator 426 based on the vibration sensor signal from the vibration sensor 430.

When used in the context of adjusting a force applied to the display 420, adjusting the audio signal as depicted in block 1106 may include: the audio signal 420 is adjusted in response to a force applied to the display 420 that affects the vibration of the display by the actuator 426. In this case, the operations of block 1106 may include determining an estimate of the level of force applied to the display 420 based on the vibration sensor signal as depicted in block 1108. The method 1100 may then further include adjusting the audio signal based on the estimate of the level of force as depicted in block 1110. Determining the estimate of the level of force may include comparing the vibration sensor signal to an expected signal and determining an estimate of the level of force applied to the display 420 based on the comparison. The method may further include increasing the magnitude of the audio signal based on the estimate of the level of force. One or more operations as described with reference to method 1100 may be performed using processor 408.

In some aspects, method 1100 may further include determining a change in a quality factor (Q-factor) of an electromechanical system including display 420 and actuator 426 based on the vibration sensor signal, and adjusting the audio signal based on the change in the Q-factor.

FIG. 12 is a flow chart illustrating another example of a method 1200 for generating audio using the display 420. At block 1202, the method includes vibrating the display 420 using an actuator 426 physically coupled to the display 420 based on an audio signal provided as input to the actuator 426. At block 1204, the method 1200 further includes generating a vibration sensor signal using the vibration sensor 430 physically coupled to the display 420, the vibration sensor signal proportional to a vibration of the display 420 produced in response to the vibration of the display 420 by the actuator 426.

Referring to fig. 7, when used for echo cancellation, at block 1206, the method 1200 may include generating an echo reference signal based on the vibration sensor signal, the echo reference signal corresponding to a representation of an acoustic output of the display 720 based on the vibration sensor signal. At block 1208, the method 1200 may also include canceling at least a portion of an echo signal included within a microphone input signal received by the microphone 732. Canceling at least a portion of the echo signal may include canceling the echo signal based on an echo reference signal, which is generated based on a vibration sensor signal from the vibration sensor 730. One or more operations described with reference to method 1200 may be performed using processor 708. More generally, the method 1200 may include canceling a portion of a microphone output signal from a microphone 732 of the electronic device based on the vibration sensor signal, the portion canceled corresponding to acoustic output from the display 720 due to vibration of the display captured by the microphone 732.

FIG. 13 is a flow diagram illustrating another example of a method 1300 for generating audio using a display 820 (FIG. 8A) that is part of an electronic device. Method 1300 is described with reference to fig. 8A. At block 1302, the method 1300 includes vibrating the display 820 using a first actuator 826a physically coupled to the display 820 based on a first audio signal provided as an input to the first actuator 826 a. At block 1304, the method 1300 includes generating a vibration sensor signal using a vibration sensor 830 physically coupled to the display 820, the vibration sensor signal proportional to a vibration of the display 820 produced in response to a vibration of the display 820 by the first actuator 826 a. At block 1306, the method 1300 includes vibrating a portion of the electronic device other than the display 820 (e.g., a back panel or a side panel) using a second actuator 826b physically coupled to the portion of the electronic device based on a second audio signal provided as input to the second actuator 826 b.

In some aspects, when used in the context of sound leakage cancellation, at block 1308, the method 1300 may include generating a second audio signal having a waveform that cancels vibration of the portion of the electronic device caused by vibration of the display 820. In certain aspects, the second audio signal may be generated based in part on the vibration sensor signal from the vibration sensor 830. In some aspects, the processor 808 is configured to generate a second audio signal. When generating the second audio signal, the method 1300 may include generating the second audio signal having a waveform that is out of phase with a signal based on the vibration sensor signal of the vibration sensor 830 physically coupled to the display 820.

Fig. 14 is a flow chart illustrating an example of a method 1400 for processing a vibration sensor signal from the vibration sensor 430. The method 1400 is described with reference to the audio system 422 of fig. 4B and provides an example of a portion of the vibration sensor signal processing. However, it should be understood that other processing and conditioning of the vibration sensor signal may be performed in addition to the processing described with reference to method 1400 of FIG. 14. The method 1400 may be used to generate an audio reference signal for a feedback loop for calibrating or improving an audio signal provided to the display 420 via the actuator 426 for echo cancellation, for sound leakage cancellation, and so on. The processor 408 (which may be the signal processor 418 in some implementations) may be configured to perform any of the operations of the method 1400. At block 1402, the method 1400 includes converting the vibration sensor signal to a sound pressure level signal. As mentioned above, the conversion may be based on predetermined information regarding the correlation between the vibration sensor signal and the measured sound pressure level signal. In some aspects, a linear function may be applied to the vibration sensor signal to generate a sound pressure level signal. At block 1404, the method 1400 further includes comparing the sound pressure level signal to a target sound pressure level model 446 representing audio output characteristics of the display and providing an adjusted sound pressure level signal. At block 1406, the method 1400 further includes adjusting a frequency response of the audio signal provided to the actuator 426 based on the adjusted sound pressure level signal.

The various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. The apparatus may include various hardware and/or software components and/or modules including, but not limited to, a circuit, an Application Specific Integrated Circuit (ASIC), or a processor.

Generally, where there are operations illustrated in the figures, those operations may have corresponding means plus function elements with like numerals.

Other examples of implementations of the present disclosure are defined as follows:

1. an electronic device includes a display and an actuator physically coupled to the display and configured to cause vibration of the display in response to an audio signal provided as an input to the actuator. The electronic device also includes a vibration sensor physically coupled to the display and configured to output a vibration sensor signal proportional to the vibration of the display due to the actuator. The electronic device also includes a processor operatively coupled to the vibration sensor, wherein the processor is configured to adjust the audio signal based on the vibration sensor signal from the vibration sensor.

2. The electronic device of example 1, wherein the processor is configured to adjust the audio signal in response to a force applied to the display that affects the vibration of the display.

3. The electronic device of example 2, wherein the processor is configured to determine an estimate of the level of force applied to the display based on the vibration sensor signal.

4. The electronic device of example 3, wherein the processor is configured to adjust the audio signal based on the estimate of the level of the force.

5. The electronic device of example 3, wherein the processor is configured to compare the vibration sensor signal to an expected reference signal and determine the estimate of the level of the force applied to the display based on the comparison.

6. The electronic device of example 3, wherein the processor is configured to increase the magnitude of the audio signal based on the estimate of the level of the force.

7. The electronic device of example 1, wherein the processor is configured to determine a change in a quality factor (Q-factor) of an electromechanical system including the display and the actuator based on the vibration sensor signal, the processor further configured to adjust the audio signal based on the change in the Q-factor.

8. The electronic device of example 7, wherein the processor is configured to evaluate the vibration sensor signal over a frequency range including a resonant frequency of the electromechanical system, wherein the frequency range is smaller than a speech frequency range of the audio signal, the processor being configured to determine the change in the quality factor based on the evaluation over the frequency range.

9. The electronic device of example 1, wherein the vibration sensor is an accelerometer.

10. The electronic device of example 9, wherein the accelerometer is a broadband accelerometer having a bandwidth that covers frequencies within a voice frequency range.

11. The electronic device of example 1, further comprising an audio codec operatively coupled to the vibration sensor and configured to output a digital vibration sensor signal to the processor based on the vibration sensor signal provided by the vibration sensor.

12. The electronic device of example 1, wherein the processor is configured to adjust a frequency response of the audio signal provided to the actuator via an audio amplifier based on the vibration sensor signal to provide an adjusted acoustic output from the display.

13. The electronic device of example 1, wherein the vibration sensor signal is different from the audio signal at the input of the actuator based at least in part on a physical size or structural characteristic of the display.

14. The electronic device of example 1, further comprising a second actuator physically coupled to a portion of the electronic device that is different from a location at which the actuator is physically coupled to the display and configured to cause vibration of the portion in response to a second audio signal provided as an input to the second actuator. The electronic device also includes a second vibration sensor physically coupled to the portion of the electronic device and configured to output a second vibration sensor signal proportional to the vibration of the portion. The processor is configured to adjust the second audio signal based on the second vibration sensor signal.

15. The electronic device of example 1, wherein the processor is configured to convert the vibration sensor signal to a sound pressure level signal, compare the sound pressure level signal to a target sound pressure level model representing audio output characteristics of the display, and adjust a frequency response of the audio signal based on the comparison.

16. The electronic device of example 1, wherein the processor comprises: acceleration-to-sound pressure level signal conversion circuitry operably coupled to an output from the vibration sensor, the acceleration-to-sound pressure level signal conversion circuitry configured to convert the vibration sensor signal to a sound pressure level signal. The processor further comprises: sound pressure level signal comparator circuitry operably coupled to the acceleration to sound pressure level signal conversion circuitry, the sound pressure level signal comparator circuitry configured to: the sound pressure level signal is compared to a target sound pressure level model representing audio output characteristics of the display and an adjusted sound pressure level signal is provided. The processor further comprises: frequency response correction circuitry operably coupled to the sound pressure level signal comparator circuitry and configured to receive a desired audio signal, the frequency response correction circuitry configured to: adjust the audio signal provided to the actuator based on the desired audio signal and the adjusted sound pressure level signal from the sound pressure level signal comparator circuitry, the frequency response correction circuitry configured to provide the audio signal to the actuator via an audio amplifier.

17. The electronic device of example 1, wherein the audio signal is an amplified electrical audio signal generated by an audio amplifier based on an electrical audio signal generated by the processor.

18. An electronic device includes a display. The electronic device further includes: means for causing vibration of the display based on an audio signal to provide an acoustic output from the display due to the vibration of the display. The electronic device further comprises means for sensing the vibration of the display, the vibration sensing means being configured to: outputting a vibration sensor signal proportional to the vibration of the display due to the vibration inducing device. The electronic device further includes: means for adjusting the audio signal based on the vibration sensor signal from the vibration sensing device.

19. The electronic device of example 18, wherein the adjustment device is configured to adjust the audio signal in response to a force applied to the display that affects the vibration of the display.

20. The electronic device of example 19, further comprising: means for determining an estimate of the level of force applied to the display based on the vibration sensor signal, wherein the adjusting means is configured to adjust the audio signal based on the estimate of the level of the force.

21. A method for generating audio using a display, the method comprising: vibrating the display using an actuator physically coupled to the display based on an audio signal provided as an input to the actuator. The method further comprises the following steps: generating a vibration sensor signal using a vibration sensor physically coupled to the display, the vibration sensor signal proportional to a vibration of the display due to the actuator. The method further comprises the following steps: adjusting the audio signal based on the vibration sensor signal from the vibration sensor.

22. The method of example 21, wherein conditioning the audio signal comprises: adjusting the audio signal in response to a force applied to the display that affects the vibration of the display by the actuator.

23. The method of example 22, further comprising: determining an estimate of a level of the force applied to the display by something other than the actuator based on the vibration sensor signal.

24. The method of example 23, wherein adjusting the audio signal comprises adjusting the audio signal based on the estimate of the level of the force.

25. The method of example 23, wherein determining the estimate of the level of the force comprises: comparing the vibration sensor signal to an expected signal and determining the estimate of the level of the force applied to the display based on the comparison.

26. The method of example 23, wherein adjusting the audio signal comprises increasing an intensity level of the audio signal based on the estimate of the level of the force.

27. The method of example 21, further comprising determining a change in a quality factor (Q-factor) of an electromechanical system including the display and the actuator based on the vibration sensor signal, wherein adjusting the audio signal comprises adjusting the audio signal based on the change in the Q-factor.

28. The method of example 21, wherein the vibration sensor is a broadband accelerometer having a bandwidth covering frequencies within a voice frequency range.

29. The method of example 21, wherein adjusting the audio signal includes adjusting a frequency response of the audio signal provided to the actuator based on the vibration sensor signal.

30. The method of example 21, further comprising converting the vibration sensor signal to a sound pressure level signal and comparing the sound pressure level signal to a target sound pressure level model representative of audio output characteristics of the display and providing an adjusted sound pressure level signal, wherein adjusting the audio signal comprises adjusting a frequency response of the audio signal based on the adjusted sound pressure level signal.

31. An electronic device includes a display and a first actuator physically coupled to the display and configured to cause vibration of the display in response to a first audio signal provided as an input to the first actuator. The electronic device also includes a vibration sensor physically coupled to the display and configured to output a vibration sensor signal proportional to vibration of the display due to the first actuator. The electronic device also includes a second actuator physically coupled to a portion of the electronic device and configured to cause vibration of the portion in response to a second audio signal provided as an input to the second actuator, the portion being different from a location at which the first actuator is physically coupled to the display.

32. The electronic device of example 31, further comprising a processor configured to generate the first audio signal and the second audio signal.

33. The electronic device of example 32, wherein the processor is configured to generate the second audio signal having a waveform that cancels the vibration of the portion of the electronic device caused by the vibration of the display mechanically coupled to the portion of the electronic device.

34. The electronic device of example 33, wherein the second audio signal is generated based in part on the vibration sensor signal from the vibration sensor.

35. The electronic device of example 32, wherein the processor is configured to generate the second audio signal having a waveform that is out of phase with another signal that is based on the vibration sensor signal of the vibration sensor physically coupled to the display.

36. The electronic device of example 32, wherein the second audio signal provided by the processor to the second actuator is in phase with another signal based on the vibration sensor signal of the vibration sensor physically coupled to the display.

37. The electronic device of example 32, wherein the second audio signal provided by the processor to the second actuator has a waveform that aligns vibrations of each of the display and the portion of the electronic device with each other.

38. The electronic device of example 31, further comprising a second vibration sensor physically coupled to the portion of the electronic device and configured to output a second vibration sensor signal proportional to the vibration of the portion.

39. The electronic device of example 38, further comprising a processor configured to adjust the second audio signal based on the second vibration sensor signal.

40. The electronic device of example 38, further comprising a processor configured to adjust the second audio signal based on at least one of the vibration sensor signal or the second vibration sensor signal, or a combination thereof.

41. The electronic device of example 40, wherein the processor is configured to generate the second audio signal having a waveform that cancels the vibration of the portion of the electronic device caused by the vibration of the display mechanically coupled to the portion of the electronic device.

42. The electronic device of example 31, wherein the portion of the electronic device comprises a back panel or a side panel of the electronic device.

43. The electronic device of example 31, wherein the portion of the electronic device comprises a second display.

44. The electronic device of example 31, wherein the vibration sensor is an accelerometer.

45. The electronic device of example 31, wherein the first audio signal is a first amplified electrical audio signal generated by a first audio amplifier based on a first electrical audio signal generated by a processor, wherein the second audio signal is a second amplified electrical audio signal generated by a second audio amplifier based on a second electrical audio signal generated by the processor.

46. The electronic device of example 31, further comprising a processor configured to: converting the vibration sensor signal to a sound pressure level signal; comparing the sound pressure level signal to a first target sound pressure level model representing audio output characteristics of the display to provide an adjusted sound pressure level signal; adjusting a frequency response of the first audio signal based on the adjusted sound pressure level signal; and adjusting the second audio signal based on the first audio signal.

47. The electronic device of example 46, wherein the processor is further configured to adjust the second audio signal based on a second target sound pressure level model representing audio output characteristics of the portion of the electronic device.

48. The electronic device of example 46, further comprising a second vibration sensor physically coupled to the portion of the electronic device and configured to output a second vibration sensor signal proportional to the vibration of the portion, wherein the processor is further configured to: converting the second vibration sensor signal to a second pressure level signal; comparing the second sound pressure level signal to a second target sound pressure level model representing audio output characteristics of the portion of the electronic device to provide a second adjusted sound pressure level signal; and adjusting the second audio signal based on the first audio signal and the second adjusted sound pressure level signal.

49. An electronic device comprising a display and a first means for causing vibration of the display based on a first audio signal to provide acoustic output from the display due to the vibration of the display. The electronic device also includes means for sensing the vibration of the display, the vibration sensing means configured to output a vibration sensor signal proportional to the vibration of the display. The electronic device also includes a second means for causing a vibration of a portion of the electronic device other than the display based on a second audio signal.

50. The electronic device of example 49, further comprising: means for generating the second audio signal having a waveform that cancels the vibration of the portion of the electronic device caused by the vibration of the display mechanically coupled to the portion of the electronic device, wherein the second audio signal is generated based in part on the vibration sensor signal from the vibration sensing means.

51. The electronic device of example 49, further comprising a second means for sensing vibration of the portion of the electronic device, wherein the second vibration sensing means is configured to output a second vibration sensor signal proportional to the vibration of the portion of the electronic device.

52. A method for generating audio using a display that is part of an electronic device, the method comprising: vibrating the display using a first actuator physically coupled to the display based on a first audio signal provided as an input to the first actuator. The method further comprises the following steps: generating a vibration sensor signal using a vibration sensor physically coupled to the display, the vibration sensor signal being proportional to a vibration of the display in response to the vibration of the display by the first actuator. The method further comprises the following steps: vibrating a portion of the electronic device using a second actuator physically coupled to the portion of the electronic device different from the display based on a second audio signal provided as an input to the second actuator.

53. The method of example 52, further comprising generating the second audio signal having a waveform that cancels the vibration of the portion of the electronic device caused by the vibration of the display mechanically coupled to the portion of the electronic device.

54. The method of example 53, wherein the second audio signal is generated based in part on the vibration sensor signal from the vibration sensor.

55. The method of example 52, further comprising generating the second audio signal having a waveform that is out of phase with a signal based on the vibration sensor signal of the vibration sensor physically coupled to the display.

56. The method of example 52, wherein the second audio signal is in phase with another signal based on the vibration sensor signal of the vibration sensor.

57. The method of example 52, further comprising: generating a second vibration sensor signal using a second vibration sensor physically coupled to the portion of the electronic device, the second vibration sensor signal proportional to the vibration of the portion.

58. The method of example 57, further comprising adjusting the second audio signal based on the second vibration sensor signal.

59. The method of example 52, further comprising: the method includes converting the vibration sensor signal to a sound pressure level signal, comparing the sound pressure level signal to a first target sound pressure level model representing audio output characteristics of the display to provide an adjusted sound pressure level signal, adjusting a frequency response of the first audio signal based on the adjusted sound pressure level signal, and adjusting the second audio signal based on the first audio signal.

60. The method of example 59, further comprising: adjusting the second audio signal based on a second target sound pressure level model representing audio output characteristics of the portion of the electronic device.

As used herein, the term "determining" encompasses a variety of actions. For example, "determining" may include calculating (computing), processing, exporting, investigating, looking up (e.g., looking up in a table, a database or another data structure), confirming, etc. Further, "determining" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Further, "determining" may include resolving, selecting, establishing, and the like.

As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to encompass: a. b, c, ab, ac, bc, and abc, and any combination of a plurality of the above elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other order of a, b, and c).

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an ASIC, a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a sequence of specific steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

The functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in hardware, an example hardware configuration may include a processing system in the wireless node. The processing system may be implemented with a bus architecture. The buses may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including the processor, the machine-readable medium, and the bus interface. A bus interface may be used to connect a network adapter or the like to the processing system via the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like.

It is to be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.