阅读说明：本技术 声音处理装置、声音处理方法和程序 (Sound processing device, sound processing method, and program ) 是由 板桥徹德 林繁利 中川亨 渡边隆太郎 于 2018-10-25 设计创作，主要内容包括：声像定位处理单元41相对于从声源单元20提供的音频信号执行音频信号处理以定位再现音频的声像。控制单元46基于由姿势倾斜信息生成单元30生成并且指示收听者的收听姿势的倾斜的姿势倾斜信息来控制声像定位处理单元的音频信号处理,从而根据收听姿势的倾斜来调整声像将被定位的位置。例如,根据收听者的收听姿势的向前倾斜向上调整声像将被定位的位置,而根据收听姿势的向后倾斜向下调整声像将被定位的位置,由此声像将被定位的位置的高度被调整为恒定,而与收听姿势的向前倾斜和向后倾斜无关。因此,可以防止由于收听姿势的倾斜的变化而引起的声像的位置不自然地移动。(The sound image localization processing unit 41 performs audio signal processing with respect to the audio signal supplied from the sound source unit 20 to localize the sound image of the reproduced audio. The control unit 46 controls the audio signal processing of the sound image localization processing unit based on the posture inclination information generated by the posture inclination information generating unit 30 and indicating the inclination of the listening posture of the listener, thereby adjusting the position where the sound image is to be localized in accordance with the inclination of the listening posture. For example, the position where the sound image is to be localized is adjusted upward in accordance with the forward tilt of the listening posture of the listener, and the position where the sound image is to be localized is adjusted downward in accordance with the backward tilt of the listening posture, whereby the height of the position where the sound image is to be localized is adjusted to be constant regardless of the forward and backward tilts of the listening posture. Therefore, it is possible to prevent the position of the sound image from moving unnaturally due to a change in the inclination of the listening posture.)

1. An acoustic processing apparatus comprising:

a sound image localization processing unit that performs sound signal processing for localizing a sound image of a reproduced sound; and

a control section that controls the sound signal processing performed by the sound image localization processing section based on a tilt of a listening posture of a listener who reproduces the sound, and adjusts a localization position of the sound image according to the tilt of the listening posture.

2. The acoustic processing apparatus according to claim 1,

wherein the tilt of the listening posture is a tilt in a front-rear direction.

3. The acoustic processing apparatus according to claim 2,

wherein the control section adjusts the localization position of the sound image in the up-down direction according to the inclination of the listening posture.

4. The acoustic processing apparatus according to claim 3,

wherein the control section adjusts the localization position of the sound image in the upward direction in accordance with the inclination of the listening posture in the front direction set by the listener, and adjusts the localization position of the sound image in the downward direction in accordance with the inclination of the listening posture in the rear direction.

5. The acoustic processing apparatus according to claim 4,

wherein the control section adjusts the height of the localization position of the sound image to a fixed height regardless of the inclination of the listening posture in the front-rear direction.

6. The acoustic processing apparatus according to claim 3,

wherein the control section adjusts the localization position of the sound image in the up-down direction according to the inclination of the listening posture set by an external equipment.

7. The acoustic processing apparatus according to claim 1,

the sound image localization processing section localizes the sound image of the reproduced sound by filter processing using a transfer function of the sound from the virtual speaker to the listener, an

The control section switches the transfer function according to the tilt of the listening posture, and adjusts the localization position of the sound image.

8. The acoustic processing apparatus according to claim 1,

wherein the sound image localization processing section supplies the sound signal subjected to the sound signal processing to a speaker device provided at a predetermined position near the head of the listener.

9. The acoustic processing apparatus according to claim 8,

wherein the speaker device is provided at a headrest position on a seatback of a chair on which the listener sits.

10. The acoustic processing apparatus of claim 9, further comprising:

a tilt detection unit that detects a tilt of the seatback,

wherein the control section uses the inclination of the seatback detected by the inclination detection section as the inclination of the listening posture.

11. The acoustic processing apparatus of claim 8, further comprising:

a correction processing section that performs correction processing on the sound signal processed by the sound image localization processing section based on correction control information corresponding to a position of the head of the listener with respect to the speaker device,

wherein the sound signal subjected to the correction processing performed by the correction processing section is supplied to the speaker device.

12. An acoustic processing method, comprising:

sound signal processing for localizing a sound image of a reproduced sound is executed by a sound image localization processing section; and

controlling, by a control section, the sound signal processing performed by the sound image localization processing section based on the inclination of the listening posture of the listener who reproduces the sound, and adjusting, by the control section, the localization position of the sound image according to the inclination of the listening posture.

13. A program for causing a computer to execute sound signal processing, comprising:

performing sound signal processing for localizing a sound image of a reproduced sound; and

the sound signal processing is controlled based on the tilt of the listening posture of the listener reproducing the sound, and the localization position of the sound image is adjusted in accordance with the tilt of the listening posture.

Technical Field

The present technology relates to an acoustic processing apparatus, an acoustic processing method, and a program. The present technology makes it possible to prevent unnatural movement of the position of the sound image due to a change in the inclination of the listening posture.

Background

Conventionally, a sound whose sound image is to be successfully localized has been provided regardless of its use position. For example, according to patent document 1, for example, after performing processing of localizing a sound image of a reproduced sound at a predetermined position on a sound signal, correction processing is performed in consideration of the position of the head of a listener and the position of a speaker device mounted in a headrest.

Reference list

Patent document

Patent document 1: japanese patent application laid-open No. 2003-111200

Disclosure of Invention

Technical problem

Meanwhile, for example, in the case where the listener is seated on the reclining seat and a sound source (such as a speaker device) is disposed in front of the reclining seat, the position of the sound image is a fixed position regardless of the tilt of the reclining seat. However, in the case where the speaker device mounted in the headrest of the recumbent seat outputs the reproduced sound described in patent document 1, the position of the sound image of the reproduced sound moves unnaturally in the up-down direction according to the inclination angle of the recumbent seat. For example, when the reclining angle of the recumbent seat is increased, the position of the sound image reproducing the sound moves toward the zenith direction.

Therefore, an object of the present technology is to provide an acoustic processing apparatus, an acoustic processing method, and a program that make it possible to prevent unnatural movement of the position of a sound image due to a change in the front-rear direction of the inclination of a listening posture.

Solution to the problem

According to a first aspect of the present technology, an acoustic processing apparatus includes:

a sound image localization processing unit that performs sound signal processing for localizing a sound image of a reproduced sound; and

a control section that controls the sound signal processing performed by the sound image localization processing section based on the inclination of the listening posture of the listener who reproduces the sound, and adjusts the localization position of the sound image according to the inclination of the listening posture.

According to the present technology, the sound image localization processing section performs sound signal processing for localizing the sound image of the reproduced sound by filter processing using a transfer function of sound from the virtual speaker regarding localization of the sound image to the listener reproducing the sound. The control section controls the sound signal processing performed by the sound image localization processing section based on the inclination in the front-rear direction of the listening posture of the listener, and adjusts the localization position of the sound image in accordance with the inclination of the listening posture. For example, the control section performs control in such a manner that the localization position of the sound image is adjusted in the up-down direction in accordance with the inclination of the listening posture, the localization position of the sound image is adjusted in the upward direction in accordance with the inclination of the listening posture set by the listener in the front direction, the localization position of the sound image is adjusted in the downward direction in accordance with the inclination in the rear direction, and the height of the localization position of the sound image is adjusted to a fixed height regardless of the inclination of the listening posture in the front-rear direction. In addition, the control section may adjust the localization position of the sound image in the up-down direction according to the inclination of the listening posture set by the external equipment.

The sound image localization processing section supplies the sound signal subjected to the sound signal processing to the speaker device provided at a predetermined position near the head of the listener (such as a headrest position on a seatback of a chair on which the listener is seated). In addition, the acoustic processing apparatus further includes a tilt detection section that detects a tilt of the seat back, and the control section uses the tilt of the seat back detected by the tilt detection section as the tilt of the listening posture. In addition, the acoustic processing apparatus further includes a correction processing section that performs correction processing on the sound signal processed by the sound image localization processing section based on correction control information corresponding to a position of the head of the listener with respect to the speaker device. The sound signal subjected to the correction processing performed by the correction processing section may be supplied to the speaker device.

According to a second aspect of the present technology, an acoustic processing method includes:

performing, by a sound image localization processing section, sound signal processing for localizing a sound image of a reproduced sound at a predetermined position; and

the sound signal processing performed by the sound image localization processing section is controlled by the control section based on the inclination of the listening posture of the listener who reproduces the sound, and the position of the sound image is adjusted by the control section according to the inclination of the listening posture.

According to a third aspect of the present technology, a program for causing a computer to execute sound signal processing includes:

performing sound signal processing for localizing a sound image of a reproduced sound at a predetermined position; and

the sound signal processing is controlled based on the inclination of the listening posture of a listener reproducing sound, and the position of the sound image is adjusted in accordance with the inclination of the listening posture.

Note that the program of the present technology is a program that can be provided using a storage medium and a communication medium (for example, a storage medium such as an optical disk, a magnetic disk, a semiconductor memory, or a communication medium such as a network) provided to a general-purpose computer that can execute various program codes in a computer-readable form. By providing such a program in a computer-readable form, processing corresponding to the program is executed on a computer.

Advantageous effects of the invention

According to the present technology, sound signal processing for localizing a sound image of a reproduced sound is performed, the sound signal processing is controlled based on the inclination of the listening posture of a listener reproducing the sound, and the localization position of the sound image is adjusted according to the inclination of the listening posture. This makes it possible to prevent the position of the sound image from moving unnaturally in the up-down direction due to the inclination of the posture of the listener in the front-rear direction. Note that the effects described in this specification are merely examples, and are not limiting. There may be additional effects.

Drawings

Fig. 1 is a diagram showing an example of the configuration of an acoustic system.

Fig. 2 is a diagram showing an example of the arrangement of a speaker device.

Fig. 3 is a diagram showing an example of the configuration of the first embodiment of the acoustic processing section.

Fig. 4 is a diagram for describing the principle of sound image localization processing.

Fig. 5 is a diagram showing an example of a case of switching between a plurality of heights of real channel speakers.

Fig. 6 is a flowchart showing the operation of the acoustic processing section.

Fig. 7 is a diagram showing an example of the position of the sound image of the reproduced sound and the inclination of the posture of the listener in the front-rear direction.

Fig. 8 is a diagram showing an example of the configuration of the second embodiment of the acoustic processing section.

Fig. 9 is a diagram for describing the principle of sound image localization processing.

Detailed Description

Embodiments for implementing the present technology will be described below. Note that the description will be given in the following order.

1. Configuration of an acoustic system

2. First embodiment

3. Second embodiment

4. Other embodiments

<1. configuration of Acoustic System >

Hereinafter, with reference to the drawings, a configuration of an acoustic system using an acoustic processing apparatus according to the present technology will be described. Fig. 1 shows an example of the configuration of an acoustic system. The acoustic system 10 includes a sound source unit 20, a posture inclination information generating unit 30, an acoustic processing unit 40, and a speaker device 50. The acoustic processing section 40 corresponds to an acoustic processing apparatus according to the present technology.

The sound source unit 20 has at least one of a recording medium reproduction function and a signal reception function. The recording medium reproduction function is a function of outputting a sound signal to the outside. The sound signal is obtained by reproducing content stored in a recording medium (such as a hard disk device or a memory device, for example) fixed to the sound source part 20 or a recording medium (such as a disk-shaped recording medium or a memory device, for example) detachably attached to the sound source part 20. The signal receiving function is a function of outputting a sound signal of a content obtained by receiving a radio wave or a sound signal of a content received via a network to the outside. The sound source unit 20 outputs a sound signal to the acoustic processing unit 40, and outputs the sound signal by using a recording medium reproduction function or a signal reception function.

The posture-tilt-information generating section 30 generates posture tilt information indicating the tilt of the listening posture of the listener, and outputs the generated posture tilt information to the acoustic processing section 40. The posture-inclination-information generating section 30 includes an inclination detecting section configured such that a position detecting sensor, an inclination sensor, and the like are installed in, for example, a recumbent seat in which a listener sits. The position detection sensor indicates a tilted position of the seat back. The tilt sensor detects a tilt angle of the seat back. The posture inclination information generating section 30 generates posture inclination information indicating an inclination of the posture in the front-rear direction while using the inclination of the seatback detected by the inclination detecting section as the inclination of the posture of the listener in the front-rear direction. In addition, in the case where the exterior equipment controls the tilt of the seatback of the recumbent seat, the posture tilt information generation section 30 may use control information for controlling the tilt of the seatback as the posture tilt information. In addition, in the case of a seat in which the seat back is integrated with the seating surface at a predetermined angle, the posture inclination information generation section 30 may use, as the posture inclination information, the result of detecting the inclination of the seat back or control information for inclining the whole of the reclining seat to incline the seat back in a similar manner. In addition, the posture-inclination-information generating section 30 may also recognize an object by using an image capturing the listener, detect the inclination of the posture of the head of the listener in the front-rear direction based on the recognition result, and generate posture inclination information. In addition, as the information indicating the inclination of the listening posture of the listener, a detection result obtained by mounting a pressure sensor in the seatback of the recumbent seat may also be used. In this case, the inclination angle or the inclined position of the recumbent seat or the sitting posture of the listener may be detected or estimated from the output result of the pressure sensor.

The acoustic processing unit 40 performs a process of adjusting the localization position of the sound image of the reproduced sound on the sound signal supplied from the sound source unit 20 based on the posture inclination information generated by the posture inclination information generating unit 30, and outputs the processed sound signal to the speaker device 50. Note that details of the acoustic processing section 40 will be described later.

The speaker device 50 is disposed at a predetermined position near the head of the listener. The speaker device 50 includes, for example, a left channel speaker SPL and a right channel speaker SPR, although they are not shown. Each of the left channel speaker SPL and the right channel speaker SPR may include a single speaker, which may be a so-called hi-fi speaker including a super tweeter or a woofer and making it possible to output high-quality sound.

Fig. 2 shows an example of the arrangement of the speaker device. The speaker device 50 is provided at a headrest position on a seat back 61 of the seat 60. The headrest position is a position near the head of the listener LS. In addition, the left channel speaker SPL of the speaker apparatus 50 is disposed on the left side of the head. The right channel speaker SPR of the speaker apparatus 50 is disposed on the right side of the head. The left channel speaker SPL outputs reproduced sound based on the left channel sound signal supplied from the acoustic processing section 40. In addition, the right channel speaker SPR outputs reproduced sound based on the right channel sound signal supplied from the acoustic processing section 40.

<2 > first embodiment

Next, a first embodiment of the acoustic processing section will be described. Note that, according to the first embodiment, a case will be described in which the recumbent seat is an automobile seat, the head of the occupant is supported by a headrest, and the headrest includes a speaker device. In this case, a listener (an occupant of the automobile) sitting in the recumbent seat hears the reproduced sound output from the left channel speaker SPL and the right channel speaker SPR located diagonally behind the head of the listener.

The acoustic processing portion according to the first embodiment moves the position of the sound image of the sound reproduced by the speaker mounted in the headrest to the position of the sound image of the sound reproduced by the virtual speaker, and thereby eliminates the feeling of strangeness and discomfort generated when the reproduced sound is heard from a position near the rear of the head of the listener or a position behind the ears of the listener. In addition, the localization position of the sound image of the reproduced sound is adjusted to a desired position based on the inclination of the posture of the listener in the front-rear direction. It is assumed that the sound signal output from the sound source unit 20 to the acoustic processing unit 40 is a binaural signal.

Fig. 3 shows an example of the configuration of the first embodiment of the acoustic processing section. The acoustic processing section 40 includes a sound image localization processing section 41, a correction processing section 44, and a control section 46.

The sound image localization processing unit 41 performs sound signal processing for localizing the sound image of the reproduced sound. Specifically, the sound image localization processing section 41 performs processing of localizing the sound image of the reproduced sound output from the left channel speaker SPL and the right channel speaker SPR at the position of the sound image of the sound reproduced by the virtual left channel speaker VSPL and the virtual right channel speaker VSPR.

The correction processing section 44 performs correction processing on the sound signal output from the sound image localization processing section 41 as if the sound signal was accurately output from the virtual left channel speaker VSPL and the virtual right channel speaker VSPR. This makes it possible to eliminate the feeling of strangeness and discomfort generated when the reproduced sound is heard from a position near the back of the head of the listener or a position behind the ears of the listener, and this allows the listener to hear the sound as a natural sound.

The control section 46 controls the sound signal processing performed by the sound image localization processing section 41 based on the inclination of the listening posture of the listener who reproduces the sound, and adjusts the localization position of the sound image in accordance with the inclination of the listening posture. For example, the control portion 46 adjusts the localization position of the sound image of the reproduced sound in the up-down direction according to the inclination of the listening posture, and controls the localization position so that the position of the sound image of the reproduced sound does not move unnaturally in the up-down direction even when the inclination angle of the seatback of the recumbent seat is changed.

Next, details of respective portions of the acoustic processing apparatus according to the first embodiment will be described. First, before describing the sound image localization processing part 41, the principle of the sound image localization processing will be described. Fig. 4 is a diagram for describing the principle of the sound image localization process.

As shown in fig. 4, it is assumed that the position of the virtual head DH is the position of a listener in a predetermined reproduction sound field. An actual left channel speaker (hereinafter, referred to as a "real left channel speaker") RSPL and an actual right channel speaker (hereinafter, referred to as a "real right channel speaker") RSLR are provided at a left virtual speaker position and a right virtual speaker position (positions assumed as positions of speakers) to be localized with respect to a sound image of a listener at a position of the virtual head DH.

Next, the two ear portions of the virtual head DH collect sounds output from the real left channel speaker RSPL and the real right channel speaker RSPR, and transfer functions (HRTFs) are measured in advance. The transfer function (HRTF) represents how the sound output from the real left channel speaker RSPL and the real right channel speaker RSPR changes when the sound reaches both ear portions of the assumed head DH.

As shown in fig. 4, according to the first embodiment, M11 is a transfer function of sound from a real left channel speaker RSPL to the left ear of a virtual head DH, and M12 is a transfer function of sound from a real left channel speaker RSPL to the right ear of a virtual head DH. In a similar manner, M21 is the transfer function of sound from the real right channel speaker RSPR to the left ear of the virtual head DH, and M22 is the transfer function of sound from the real right channel speaker RSPR to the right ear of the virtual head DH.

In this case, the sound signals of the sound output from the left channel speaker SPL and the right channel speaker SPR of the headrest located near the ears of the listener are processed by using the previously measured transfer functions described above with reference to fig. 4. Subsequently, the left channel speaker SPL and the right channel speaker SPR output the reproduced sound of the processed sound signal.

This makes it possible to localize sound images of reproduced sounds output from the left channel speaker SPL and the right channel speaker SPR, so that the listener feels as if the reproduced sounds output from the left channel speaker SPL and the right channel speaker SPR are output from the positions of the virtual left channel speaker VSPL located at the position of the real left channel speaker RSPL and the virtual right channel speaker VSPR located at the position of the real right channel speaker RSPR.

In addition, by changing the heights of the real channel speakers, transfer functions M11, M12, M21, and M22 are generated with respect to the respective heights. Fig. 5 shows an example of a case of switching between a plurality of heights of real channel speakers. The transfer functions M11, M12, M21, and M22 are measured in advance with respect to the respective heights while changing the heights of the real left channel speaker RSPL and the real right channel speaker RSPR to the heights of the positions PS-L, PS-M and PS-H.

Note that, here, the virtual head DH has been used to measure a transfer function (HRTF). However, the present technology is not limited thereto. The transfer function of sound can also be measured when a person is actually sitting in the reproduced sound field for measuring the transfer function and a microphone is placed near his/her ear.

The sound image localization processing part 41 shown in fig. 3 performs a filtering process by using the previously measured transfer function. The sound image localization processing section 41 includes four filters 411, 412, 413, and 414 and two adders 415 and 416.

The filter 411 is a filter that processes the left channel sound signal supplied from the sound source section 20 by using the transfer function M11, and supplies the processed sound signal to the adder 415 for the left channel. In addition, the filter 412 is a filter that processes the left channel sound signal supplied from the sound source section 20 by using the transfer function M12, and supplies the processed sound signal to the adder 416 for the right channel.

In addition, the filter 413 is a filter that processes the right channel sound signal supplied from the sound source section 20 by using the transfer function M21, and supplies the processed sound signal to the adder 415 for the left channel. In addition, the filter 414 is a filter that processes the right channel sound signal supplied from the sound source section 20 by using the transfer function M22, and supplies the processed sound signal to the adder 416 for the right channel.

The adder 415 adds the sound signals supplied from the filter 411 and the filter 413. The adder 416 adds the sound signals supplied from the filter 412 and the filter 414.

This makes it possible to localize the sound image in such a manner that the virtual left channel speaker VSPL outputs the sound of the sound signal output from the adder 415 for the left channel and the virtual right channel speaker VSPR outputs the sound of the sound signal output from the adder 416 for the right channel.

The correction processing section 44 performs correction processing on the sound signal output from the sound image localization processing section 41, and localizes the sound output from the left channel speaker SPL and the right channel speaker SPR as if the sound were accurately output from the virtual left channel speaker VSPL and the virtual right channel speaker VSPR.

The correction processing unit 44 is an acoustic filter to which an auditory transmission system (transaural system) is applied. The auditory transmission system is a technique that can achieve an effect similar to that of a binaural system even in the case of using speakers. A binaural system is a method of accurately reproducing sound by using headphones.

With reference to the example shown in fig. 3, an auditory transmission system will be described. The auditory transmission system cancels the influence of the transfer functions G11, G12, G21, and G22 of the sounds output from the left channel speaker SPL and the right channel speaker SPR to the respective left and right ears of the listener from the sounds output from the respective speakers.

In other words, the correction processing section 44 eliminates the influence of the transfer function from the sound to be output from the left channel speaker SPL and the right channel speaker SPR in the reproduction sound field. This makes it possible to accurately localize the sound images of the sounds output from the left channel speaker SPL and the right channel speaker SPR at positions corresponding to the virtual speaker positions. In order to cancel the influence of the transfer functions of the sounds from the left channel speaker SPL and the right channel speaker SPR to the left and right ears of the listener, for example, the correction processing section 44 includes filters 441, 442, 443, and 444 and adders 445 and 446 for processing the sound signals in accordance with the inverse function of the transfer functions of the sounds from the right channel speaker SPR to the left and right ears of the listener.

Note that when the shape or material of the headrest, the mounting position of the speaker device, the performance or characteristics of the speakers, or the like is changed, the transfer functions of the sounds from the left channel speaker SPL and the right channel speaker SPR of the headrest to the left and right ears of the listener are changed. In other words, it can be said that different transfer functions are prepared for different shapes of headrests including speaker devices. Therefore, from the transfer function measured by using the headrest to be used, coefficient data for eliminating the influence of the transfer function that would occur if sound were heard by using the headrest is set in advance, and the coefficient data is stored. Note that the coefficient data may be stored in a storage medium, or may be stored in the correction processing section 44 or the control section 46.

As described above, each of the respective filters 441, 442, 443, and 444 of the correction processing section 44 performs the correction processing by using coefficient data set in advance in accordance with the shape or material of the headrest, the mounting position of the speaker device, the performance or characteristics of the speaker, and the like.

The sound signal output from the adder 415 for the left channel of the sound image localization processing section 41 is supplied to the filter 441 for the left channel and the filter 442 for the right channel of the correction processing section 44. The sound signal output from the adder 416 for the right channel of the sound image localization processing section 41 is supplied to the filter 443 for the left channel and the filter 444 for the right channel of the correction processing section 44.

Each of the respective filters 441, 442, 443, and 444 performs a filtering process on the sound signal supplied to each filter for eliminating the influence of the transfer function of the sound to the ear of the listener. The transfer function is measured by using a headrest including a left channel speaker SPL and a right channel speaker SPR.

Note that each filter of the correction processing section 44 eliminates the influence of the transfer function G11, G12, G21, or G22 in the reproduction sound field by processing the sound signal using the inverse function of the transfer function G11, G12, G21, or G22 shown in fig. 3.

The output of filter 441 is provided to adder 445 for the left channel. The output of the filter 442 is provided to an adder 446 for the right channel. In a similar manner, the output of the filter 443 is provided to an adder 445 for the left channel. The output of the filter 444 is provided to an adder 446 for the right channel.

The adders 445 and 446 add the supplied sound signals. The adder 445 outputs the added sound signal to the left channel speaker SPL. The adder 446 outputs the added sound signal to the right channel speaker SPR. This makes it possible to cancel the influence of the transfer function corresponding to the current position of the head of the listener in the reproduction sound field from the sounds output from the left channel speaker SPL and the right channel speaker SPR of the headrest. In addition, this makes it possible to localize the sound image of the sound as if the sound was accurately output from the virtual left channel speaker VSPL and the virtual right channel speaker VSPR.

The control section 46 controls the sound image localization processing section 41 based on the posture inclination information of the listener. Specifically, for example, in the case where the reclining angle of the seat back of the recumbent seat is increased, the control section 46 switches between the transfer functions M11, M12, M13, and M14 of the filters 411, 412, 413, and 414 of the sound image localization processing section 41 based on the posture tilt information, and prevents the position of the sound image that reproduces sound from moving in the upward direction.

Fig. 6 is a flowchart illustrating an operation of the acoustic processing section. In step ST1, the acoustic processing unit 40 starts acquiring posture tilt information. The acoustic processing section 40 starts acquiring the posture inclination information from the posture inclination information generating section 30, and proceeds to step ST 2. Note that, in a case where it is impossible to acquire the posture inclination information from the posture inclination information generating section 30, the acoustic processing section 40 sets the posture of the listener to the preset posture.

In step ST2, the acoustic processing section 40 sets a transfer function. The acoustic processing section 40 sets transfer functions corresponding to the inclinations of the postures of the listener in the front-rear direction for the filters 411 to 414 based on the posture inclination information acquired in step ST1, and proceeds to step ST 3.

In step ST3, the acoustic processing section 40 performs a filtering process. The acoustic processing section 40 performs a filtering process on the sound signal output from the sound source section 20 by using the set transfer function, and proceeds to step ST 4.

In step ST4, the acoustic processing section 40 determines whether the posture has changed. The acoustic processing section 40 determines whether the tilt of the posture of the listener in the front-rear direction has changed based on the posture tilt information output from the posture tilt information generating section 30. In a case where it is determined that the posture has not changed, the acoustic processing section 40 returns to step ST3 and continues to perform the filtering process. Alternatively, in a case where a posture change is detected, the acoustic processing section 40 proceeds to step ST 5.

In step ST5, the acoustic processing section 40 changes the transfer function. The acoustic processing section 40 changes the transfer function in accordance with the inclination of the posture of the listener in the front-rear direction indicated by the posture inclination information acquired from the posture inclination information generating section 30, returns to step ST3, and performs the filtering process by using the changed transfer function.

Note that, as shown in fig. 5, in the case where the transfer functions were previously measured with respect to the respective heights of the multiple levels of the real left channel speaker RSPL and the real right channel speaker RSPR, the measured transfer functions are associated with the angular ranges of the inclinations of the postures of the listener in the front-rear direction. Here, in the case where the inclination of the changed posture exceeds the angular range of the inclination of the posture corresponding to the transfer function set in step ST4, the acoustic processing section 40 proceeds to step ST5, and changes the set transfer function to the transfer function corresponding to the inclination of the changed posture.

As described above, according to the first embodiment, in the case where the left channel speaker SPL and the right channel speaker SPR of the headrest output the reproduction sound based on the 2ch sound signal output from the sound source section 20, the listener can hear the reproduction sound as if the reproduction sound were output from the virtual left channel speaker VSL and the virtual right channel speaker VSR. Therefore, although the listener actually hears the sounds output from the left channel speaker SPL and the right channel speaker SPR located diagonally behind the head of the listener, the listener hears the sounds as if the sounds were output from the front of the listener. This makes it possible to prevent the listener from feeling strangeness or discomfort as if the reproduced sound output from the left channel speaker SPL and the right channel speaker SPR were stuck to the rear side of the listener, and this allows the listener to hear the sound well.

In addition, even when the angle of the seatback of the seat is changed, it is possible to prevent the position of the sound image of the reproduced sound from moving unnaturally in the up-down direction according to the changed angle of the seatback (corresponding to the inclination of the posture of the listener in the front-rear direction). Fig. 7 shows an example of the position of the sound image of the reproduced sound and the inclination of the posture of the listener in the front-rear direction. For example, when the angle of the seat back 61 of the seat 60 is the angle shown in fig. 7(b), the localization position of the sound image of the reproduced sound is the positions of the virtual left channel speaker VSPL and the virtual right channel speaker VSPR which are disposed at the position PS-M in front of the listener LS. Here, the control section 46 adjusts the localization position of the sound image in the upward direction in accordance with the inclination in the front direction of the listening posture set by the listener, and adjusts the localization position of the sound image in the downward direction in accordance with the inclination in the rear direction. For example, when the seatback 61 is placed upright as shown in fig. 7(a) and the transfer function is fixed as described in the conventional art, the localization positions of the sound image of the reproduced sound are the positions of the virtual left channel speaker VSPL and the virtual right channel speaker VSPR that are disposed at the position PS-L in front of the listener LS. However, according to the present technology, the transfer function is changed in accordance with the inclination of the posture of the listener in the front-rear direction, and this makes it possible to set the localization position of the sound image that reproduces sound to the positions of the virtual left channel speaker VSPL and the virtual right channel speaker VSPR that are disposed at the position PS-M in front of the listener LS. In addition, when the seatback 61 is tilted as shown in fig. 7(c) and the transfer function is fixed as described in the conventional art, the localization position of the sound image of the reproduced sound is the positions of the virtual left channel speaker VSPL and the virtual right channel speaker VSPR that are disposed at the position PS-H in front of the listener LS. However, according to the present technology, the transfer function is changed in accordance with the inclination of the posture of the listener in the front-rear direction, and this makes it possible to set the localization position of the sound image that reproduces sound to the positions of the virtual left channel speaker VSPL and the virtual right channel speaker VSPR that are disposed at the position PS-M in front of the listener LS. Therefore, by adjusting the height of the localization position of the sound image to a fixed height regardless of the inclination of the listening posture in the front-rear direction, it is possible to prevent the position of the sound image of the reproduced sound from moving unnaturally in the up-down direction in accordance with the change in the inclination of the posture of the listening posture in the front-rear direction.

<3 > second embodiment

Next, a case where the sound source section 20 outputs multi-channel sound signals of two or more channels will be described. Fig. 8 is a diagram showing an example of the configuration of the second embodiment of the acoustic processing section. The sound image localization processing part 42 of the acoustic processing part 40 according to the second embodiment localizes the sound image of the sound output from the speaker based on a principle similar to that of the sound image localization processing part 41 according to the first embodiment. However, the second embodiment is different from the first embodiment in that the sound images of the sounds output from the left channel speaker SPL and the right channel speaker SPR installed in the headrest are localized as if the sound images were output from the five virtual speakers VSP1 to VSP5 indicated by dotted lines as shown in fig. 8.

Fig. 9 is a diagram for describing the principle of sound image localization processing performed by the acoustic processing section according to the second embodiment shown in fig. 8. As shown in fig. 9, it is assumed that the position of the virtual head DH is the position of a listener in a predetermined reproduction sound field. The real speakers RSP1 to RSP5 are actually provided at the positions of the virtual speakers (assumed as the positions of the speaker positions) for localizing the sound image with respect to the listener at the position of the virtual head DH. In addition, transfer functions (HRTFs) of sounds output from the respective real speakers RSP1 to RSP5 to each of the left and right ears of the virtual head DH are measured in advance.

As shown in fig. 9, according to the second embodiment, N11 is a transfer function of sound from the real speaker RSP1 to the left ear of the virtual head DH, and N12 is a transfer function of sound from the real speaker RSP1 to the right ear of the virtual head DH. In addition, N21 is a transfer function of sound from the real speaker RSP2 to the left ear of the virtual head DH, and N22 is a transfer function of sound from the real speaker RSP2 to the right ear of the virtual head DH.

In a similar manner, N31 is the transfer function of sound from the real speaker RSP3 to the left ear of the virtual head DH, and N32 is the transfer function of sound from the real speaker RSP3 to the right ear of the virtual head DH. N41 is a transfer function of sound from the real speaker RSP4 to the left ear of the virtual head DH, and N42 is a transfer function of sound from the real speaker RSP4 to the right ear of the virtual head DH. In addition, N51 is a transfer function of sound from the real speaker RSP5 to the left ear of the virtual head DH, and N52 is a transfer function of sound from the real speaker RSP5 to the right ear of the virtual head DH.

In addition, while moving the positions of the virtual speakers VSP-1 to VSP-5 in the up-down direction in a similar manner to the first embodiment, the transfer functions N11, N12, N21, N22, N31, N32, N41, N42, N51, and N52 are measured in advance with respect to a plurality of different positions.

The acoustic processing section 40 performs correction processing for eliminating the influence of a transfer function in a reproduction sound field by processing, for example, a 5-channel sound signal output from the sound source section 20 using a corresponding transfer function that has been previously measured, outputs the processed sound signal to the speaker device 50, and outputs a reproduction sound from the left channel speaker SPL and the right channel speaker SPR of the speaker device 50 mounted in the headrest.

The sound image localization processing part 42 shown in fig. 8 performs a filtering process by using the previously measured transfer function. The sound image localization processing section 42 includes 10 filters 421 to 430 and two adders 431 and 432.

The filter 421 is a filter that processes the first channel sound signal supplied from the sound source section 20 by using the transfer function N11, and supplies the processed sound signal to the adder 431 for the left channel. In addition, the filter 422 is a filter that processes the first-channel sound signal supplied from the sound source section 20 by using the transfer function N12, and supplies the processed sound signal to the adder 432 for the right channel.

The filter 423 is a filter that processes the second channel sound signal supplied from the sound source part 20 by using the transfer function N11, and supplies the processed sound signal to the adder 431 for the left channel. In addition, the filter 424 is a filter that processes the second channel sound signal supplied from the sound source portion 20 by using the transfer function N12, and supplies the processed sound signal to the adder 432 for the right channel.

The filter 425 is a filter that processes the third channel sound signal supplied from the sound source section 20 by using the transfer function N11, and supplies the processed sound signal to the adder 431 for the left channel. In addition, the filter 426 is a filter that processes the third channel sound signal supplied from the sound source section 20 by using the transfer function N12, and supplies the processed sound signal to the adder 432 for the right channel.

The filter 427 is a filter that processes the fourth channel sound signal supplied from the sound source section 20 by using the transfer function N11, and supplies the processed sound signal to the adder 431 for the left channel. In addition, the filter 422 is a filter that processes the fourth channel sound signal supplied from the sound source part 20 by using the transfer function N12, and supplies the processed sound signal to the adder 432 for the right channel.

The filter 429 is a filter that processes the fifth channel sound signal supplied from the sound source section 20 by using the transfer function N11, and supplies the processed sound signal to the adder 431 for the left channel. In addition, the filter 430 is a filter that processes the fifth channel sound signal supplied from the sound source part 20 by using the transfer function N12, and supplies the processed sound signal to the adder 432 for the right channel.

The adder 431 adds the sound signals supplied from the filters 421, 423, 425, 427, and 429. The adder 432 adds the sound signals supplied from the filters 422, 424, 426, 428, and 430.

This makes it possible to localize the sound image such that the virtual speakers VSP1 to VSP5 output the sound of the sound signal output from the adder 431 for the left channel and the sound of the sound signal output from the adder 432 for the right channel.

The correction processing section 44 according to the second embodiment is configured in a manner similar to that of the first embodiment. The correction processing section 44 performs correction processing on the sound signal output from the sound image localization processing section 42, and localizes the sound output from the left channel speaker SPL and the right channel speaker SPR as if the sound were accurately output from the virtual speakers VSP1 to VSP 5.

The control section 46 controls the sound image localization processing section 42 based on the posture inclination information of the listener. Specifically, for example, in the case where the inclination angle of the seatback of the recumbent seat is increased, the transfer functions N11, N12, N21, N22, N31, N32, N41, N42, N51, and N52 of the filters 421 to 430 of the sound image localization processing section 42 are switched based on the posture inclination information, and the position of the sound image that reproduces sound is prevented from moving in the upward direction.

As described above, according to the second embodiment, in the case where the left channel speaker SPL and the right channel speaker SPR of the headrest output reproduced sound based on the multi-channel sound signal output from the sound source section 20, the listener can hear the reproduced sound as if the reproduced sound were output from the virtual speakers VSP1 to the position of VSP-5. Therefore, in a manner similar to the first embodiment, although the listener hears the sounds output from the left channel speaker SPL and the right channel speaker SPR located diagonally behind the head of the listener, the listener hears the sounds as if the sounds were output from the front of the listener. This makes it possible to prevent the listener from feeling strangeness or discomfort as if the reproduced sound output from the left channel speaker SPL and the right channel speaker SPR were stuck to the rear side of the listener, and this allows the listener to hear the sound well. In addition, it is possible to prevent the position of the sound image of the reproduced sound from moving unnaturally in the up-down direction according to the change in the inclination of the posture of the listener in the front-rear direction.

<4 > other embodiments

In the first and second embodiments, the case has been described in which the recumbent seat is a car seat, the speaker device is mounted in a headrest provided on the top of the seat back, and the acoustic processing section 40 includes the sound image localization processing section 41(42) and the correction processing section 44. However, it is also possible to integrate the sound image localization processing part 41 with the correction processing part 44, and execute a filter process in which the process executed by the sound image localization processing part 41 and the process executed by the correction processing part 44 are combined. In addition, it is sufficient that the speaker device is mounted at a predetermined position near the head of the listener, and the predetermined position is not limited to the headrest.

In addition, it is sufficient that the acoustic processing section prevents the position of the sound image of the reproduced sound from moving unnaturally in the up-down direction in accordance with a change in the inclination of the posture of the listener in the front-rear direction. The acoustic processing section does not necessarily include a correction processing section.

In addition, the seat in which the speaker device is mounted is not limited to the car seat. For example, as described above, it is also possible to mount the speaker device in a reclining seat provided in an airplane, a train, or the like. In addition, as described above, it is also possible to mount the speaker device in a seat for an amusement facility or the like that is built in an amusement park and that carries a rider, so that the inclination of the posture of the rider in the front-rear direction is changed. In addition, as described above, it is possible to mount not only the speaker device in the seat provided in the moving object but also the speaker device in the seat provided at a fixed position. For example, the speaker device may be installed in a reclining seat in a place of rest or in a massage chair having a reclining function.

In addition, it is possible to prevent the localization position of the sound image of the reproduced sound from moving unnaturally in the up-down direction by adjusting the localization position according to the change in the inclination of the posture of the listener in the front-rear direction. In addition, it is also possible to provide a dynamic sense of realism by controlling the direction and amount of movement of the localization position of the sound image of the reproduced sound in accordance with the change in the inclination of the posture. For example, in the case where the external device automatically tilts the seat in the front-rear direction in accordance with the reproduction of the video, the control section 46 adjusts the localization position of the sound image in the up-down direction in accordance with the tilt of the listening posture set by the external device. Here, an example of adjusting the localization position of the sound image in the up-down direction according to the inclination of the listening posture set by the external apparatus will be described. In the case of automatically tilting the seat in the front-rear direction according to video reproduction by using a control signal from an external equipment, the posture tilt information generating section 30 uses the control signal from the external equipment as the posture tilt information, and the control section 46 moves the localization position of the sound image more in the moving direction of the position of the sound image of the reproduced sound corresponding to the tilt of the seat based on the posture tilt information. When the localization position of the sound image of the reproduced sound is moved as described above, for example, a quick turn behavior or the like in a scene in which the listener follows an enemy plane can be dynamically reproduced by using a simulated video of an air battle or the like between aircraft. In addition, for example, in the case where the seat is automatically inclined in the front direction in accordance with reproduction of a simulated video of a falling scene or the like, the falling behavior or the like can be dynamically reproduced by moving the localization position of the sound image in the direction opposite to the moving direction of the position of the sound image of the reproduced sound corresponding to the inclination of the seat.

The series of processes described in this specification may be executed by hardware, software, or a combination configuration thereof. In the case where the series of processes is executed by software, a program in which the processing order is recorded may be installed into a memory in a computer incorporated into dedicated hardware to thereby execute the program, or may be installed into a general-purpose computer capable of executing various types of processes to thereby execute the program.

For example, the program may be recorded in advance in a hard disk, a Solid State Drive (SSD), or a Read Only Memory (ROM) serving as a recording medium. Alternatively, the program may be temporarily or permanently stored (recorded) in a removable recording medium such as a flexible disk, a compact disc-read only memory (CD-ROM), a magneto-optical (MO) disk, a Digital Versatile Disc (DVD), a blu-ray disc (BD) (registered trademark), a magnetic disk, or a semiconductor memory. Such a removable recording medium may be provided as so-called package software.

In addition to being installed into the computer from the above-described removable recording medium, the program may be transferred from the download site to the computer in a wired or wireless manner via a network such as a Local Area Network (LAN) or the internet. The computer can receive the program transferred in this manner and install the program into a recording medium such as a hard disk contained therein.

It should be noted that the effects described in this specification are merely examples and are by no means limited thereto, and additional effects not described herein may be provided. In addition, the present technology should not be construed as being limited to the embodiments of the technology described above. The embodiments of the technology described above disclose the present technology by way of example, and it is apparent that those skilled in the art can modify or replace the embodiments without departing from the subject matter of the present technology. That is, the claims should be considered in order to determine the subject matter of the present technology.

In addition, the acoustic processing apparatus according to the present technology can also be configured as follows.

(1) An acoustic processing apparatus comprising:

a sound image localization processing unit that performs sound signal processing for localizing a sound image of a reproduced sound; and

a control section that controls the sound signal processing performed by the sound image localization processing section based on the inclination of the listening posture of the listener who reproduces the sound, and adjusts the localization position of the sound image according to the inclination of the listening posture.

(2) The acoustic processing apparatus according to (1),

wherein the tilt of the listening posture is a tilt in the front-rear direction.

(3) The acoustic processing apparatus according to (2),

wherein the control section adjusts the localization position of the sound image in the up-down direction according to the inclination of the listening posture.

(4) The acoustic processing apparatus according to (3),

wherein the control section adjusts the localization position of the sound image in the upward direction in accordance with an inclination in the front direction of the listening posture set by the listener, and adjusts the localization position of the sound image in the downward direction in accordance with an inclination in the rear direction.

(5) The acoustic processing apparatus according to (4),

wherein the control section adjusts the height of the localization position of the sound image to a fixed height regardless of the inclination of the listening posture in the front-rear direction.

(6) The acoustic processing apparatus according to (3),

wherein the control section adjusts the localization position of the sound image in the up-down direction according to the inclination of the listening posture set by the external equipment.

(7) The acoustic processing apparatus according to any one of (1) to (6),

the sound image localization processing section localizes the sound image of the reproduced sound by filter processing using a transfer function of the sound from the virtual speaker to the listener, an

The control section switches the transfer function according to the inclination of the listening posture, and adjusts the localization position of the sound image.

(8) The acoustic processing apparatus according to any one of (1) to (7),

wherein the sound image localization processing section supplies the sound signal subjected to the sound signal processing to the speaker device provided at a predetermined position near the head of the listener.

(9) The acoustic processing apparatus according to (8),

wherein the speaker device is provided at a headrest position on a seatback of a chair on which a listener sits.

(10) The acoustic processing apparatus according to (9), further comprising:

a tilt detection unit that detects a tilt of the seat back,

wherein the control section uses the inclination of the seatback detected by the inclination detection section as the inclination of the listening posture.

(11) The acoustic processing apparatus according to any one of (8) to (10), further comprising:

a correction processing section that performs correction processing on the sound signal processed by the sound image localization processing section based on correction control information corresponding to a position of the head of the listener with respect to the speaker device,

wherein the sound signal subjected to the correction processing performed by the correction processing section is supplied to the speaker device.

INDUSTRIAL APPLICABILITY

By using the acoustic processing apparatus, the acoustic processing method, and the program according to the present technology, sound signal processing for localizing a sound image of a reproduced sound is performed, the sound signal processing is controlled based on the inclination of the listening posture of a listener reproducing the sound, and the localization position of the sound image is adjusted according to the inclination of the listening posture. This makes it possible to prevent the position of the sound image from moving unnaturally in the up-down direction due to the inclination of the posture of the listener in the front-rear direction. The present technology is applicable to an apparatus that localizes a sound image by using reproduced sound from a seat installed in a moving object, a fixed facility, or the like.

List of reference marks

10 acoustic system

20 sound source part

30 posture/inclination information generating unit

40 acoustic processing unit

41. 42 sound image localization processing unit

44 correction processing part

46 control part

50 speaker device

60 seat

61 seat back

411 to 414, 421 to 430, 441 to 444 filters

415. 416, 431, 432, 445, 446 adders.