阅读说明：本技术 一种提升室内语言清晰度的方法和系统 (Method and system for improving indoor language definition ) 是由 张承云 欧阳理昊 凌嘉乐 于 2020-05-09 设计创作，主要内容包括：本发明公开了一种提升室内语言清晰度的方法,包括：获取室内建筑的几何尺寸,根据所述几何尺寸建立室内仿真模型；在所述室内仿真模型中选择若干个参数评价点,根据预设的清晰度评价参数计算策略在所述参数评价点中选取若干个清晰度薄弱点；所述清晰度薄弱点用于作为在室内布置扩散体和反射材料的参考位置；计算所述清晰度薄弱点在所选倍频程频带下的平均混响时间；根据预设的所述倍频程频带的目标混响时间和所述平均混响时间计算所述倍频程频带对应的吸声增量；根据所述吸声增量选择吸声材料；所述吸声材料用于布置在室内的第一预设位置处。本发明还公开一种提升室内语言清晰度的系统。采用本发明实施例,能有效提升室内的语言清晰度。(The invention discloses a method for improving indoor language definition, which comprises the following steps: acquiring the geometric dimension of an indoor building, and establishing an indoor simulation model according to the geometric dimension; selecting a plurality of parameter evaluation points in the indoor simulation model, and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; the point of weakness is used as a reference location for the placement of the diffuser and reflective material within the chamber; calculating an average reverberation time of the sharpness vulnerability at the selected octave frequency band; calculating a sound absorption increment corresponding to the octave frequency band according to preset target reverberation time and the average reverberation time of the octave frequency band; selecting a sound absorbing material according to the sound absorption increment; the sound absorbing material is configured to be disposed at a first predetermined location within a room. The invention also discloses a system for improving the indoor language definition. By adopting the embodiment of the invention, the indoor speech definition can be effectively improved.)

1. A method for enhancing indoor speech intelligibility, comprising:

acquiring the geometric dimension of an indoor building, and establishing an indoor simulation model according to the geometric dimension;

selecting a plurality of parameter evaluation points in the indoor simulation model, and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

calculating an average reverberation time of the sharpness weakness point at the selected octave frequency band;

calculating a sound absorption increment corresponding to the octave frequency band according to preset target reverberation time and the average reverberation time of the octave frequency band;

selecting a sound absorbing material according to the sound absorption increment; wherein the sound absorbing material is adapted to be arranged at a first predetermined position within a room.

2. The method for enhancing speech intelligibility in a room of claim 1 wherein, after disposing the diffuser, reflective material and sound absorbing material in the room, the method further comprises:

selecting a plurality of definition weak points from the parameter evaluation points according to a preset definition evaluation parameter calculation strategy;

judging whether the current definition weak point is the same as the definition weak point obtained by the last calculation;

if yes, taking the current definition weak point as a reference position for arranging the reflecting material indoors; if not, the current point of weakness of the definition is taken as a reference location for arranging the diffuser and reflective material within the chamber.

3. The method for enhancing speech intelligibility in a room of claim 1 wherein, after disposing the diffuser, reflective material and sound absorbing material in the room, the method further comprises:

acquiring the background noise level at the sharpness weak point;

acquiring a sound pressure level at the definition weak point when a sound is emitted at a sound source position preset indoors;

calculating a signal-to-noise ratio from the background noise level and the sound pressure level;

and when the sound pressure level is smaller than a preset first threshold or the signal-to-noise ratio is smaller than a preset second threshold, judging that sound amplifying equipment needs to be installed at a second preset position in the room.

4. The method for improving indoor language intelligibility of claim 1 or 2 wherein said selecting a plurality of intelligibility weaknesses among said parameter evaluation points according to a predetermined intelligibility assessment parameter calculation strategy comprises:

calculating the impulse response of the parameter evaluation point;

calculating initial evaluation parameters of each parameter evaluation point under the selected octave frequency band according to the impulse response;

calculating an initial evaluation parameter mean value of each parameter evaluation point as a definition evaluation parameter of the parameter evaluation point;

and acquiring a plurality of parameter evaluation points with the minimum definition evaluation parameter as definition weak points.

5. The method for improving indoor speech intelligibility of claim 1 wherein said indoor structure is a structure having seats, and said selecting a plurality of parameter evaluation points in said indoor simulation model comprises:

and uniformly selecting a plurality of parameter evaluation points in the seats in the indoor simulation model.

6. The method for improving indoor speech intelligibility of claim 1 wherein the sound absorbing material comprises a middle-low frequency sound absorbing material and a middle-high frequency sound absorbing material, and the first predetermined location comprises a rear wall of the indoor building, an included angle between a ceiling and a side wall of the indoor building, and a junction between a front wall and the side wall; the middle-low frequency sound absorption material is used for being arranged on the rear wall of the indoor building, and the middle-high frequency sound absorption material is used for being arranged at the corner between the ceiling and the side wall of the indoor building and the junction between the front wall and the side wall.

7. The method for enhancing intelligibility of indoor speech according to claim 1 wherein said reflective material is disposed at a ceiling location corresponding to said point of weakness; wherein the reflective material is arranged according to a preset reflective material arrangement strategy.

8. The method of enhancing indoor speech intelligibility of claim 7 wherein said reflective material placement strategy comprises:

calculating a direct sound path from an indoor preset sound source position to a listener position;

calculating a first reflected acoustic path from the reflective material at the acoustic source location;

calculating a second reflected acoustic path with the reflective material at the listener position;

calculating an included angle between the second reflected sound path and the direct sound path and a reflected sound delay time according to the direct sound path, the first reflected sound path and the second reflected sound path;

adjusting the inclination between the reflecting material and the horizontal plane of the ceiling until the included angle is less than or equal to a preset included angle threshold value and the reflected sound delay time is less than or equal to a preset delay time threshold value.

9. A system for enhancing speech intelligibility in a room, comprising:

the simulation model establishing module is used for acquiring the geometric dimension of an indoor building and establishing an indoor simulation model according to the geometric dimension;

the definition weak point acquisition module is used for selecting a plurality of parameter evaluation points in the indoor simulation model and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

the mean reverberation time calculation module is used for calculating the mean reverberation time of the definition weak points in the selected octave frequency band;

the sound absorption increment calculation module is used for calculating a sound absorption increment corresponding to the octave frequency band according to the preset target reverberation time and the average reverberation time of the octave frequency band;

the sound absorption material acquisition module is used for selecting a sound absorption material according to the sound absorption increment; wherein the sound absorbing material is adapted to be arranged at a first predetermined position within a room.

10. The system for enhancing speech intelligibility in a room of claim 9 wherein, after disposing the diffuser, reflective material and sound absorbing material in the room, the system further comprises:

a background noise level measurement acquisition module for acquiring a background noise level at the sharpness weak point;

a sound pressure level acquisition module for acquiring a sound pressure level at the clarity weak point when a sound is emitted at a sound source position preset indoors;

the signal-to-noise ratio calculation module calculates a signal-to-noise ratio according to the background noise level and the sound pressure level;

and the comparison module is used for judging that sound amplifying equipment needs to be installed at a second preset position in the room when the sound pressure level is smaller than a preset first threshold or the signal-to-noise ratio is smaller than a preset second threshold.

Technical Field

The invention relates to the technical field of building acoustics and signal processing, in particular to a method and a system for improving indoor language definition.

Background

The classroom is the main place of school teaching, and many classrooms have the problem of language definition, especially middle and rear seats and large classrooms. The language definition in the classroom can influence the quality of class of students, and the low language definition can lead to the student to arouse the distraction, study effect subalternation problem because of not hearing mr's lecture content. The low speech intelligibility in the classroom makes the teacher involuntarily increase the volume of lectures, which is easily exhausted and not good for throat health. The language definition in a classroom is mainly related to factors such as the sound pressure level of a sound source (e.g., a lecturer), the distance between a listening position and the sound source, reflected sound in the classroom, spectral characteristics of sound, noise (e.g., fan noise), and the like, and therefore, in order to improve the language definition in the classroom, consideration needs to be given to various aspects such as classroom site selection, classroom internal body type design, building and decoration materials, and the like. However, in the current school construction, no special design is basically provided for improving the language definition of the classroom, the relevant management departments of the school do not know the factors influencing the language definition of the classroom enough, and the problem can be solved only by providing the microphone and the loudspeaker, but the problem is not found in practical application, background noise and reverberant sound can be amplified by sound amplifying equipment in the classroom while the teaching volume of a teacher is amplified, and the sound energy ratio is not changed, so the language definition cannot be improved.

Disclosure of Invention

The embodiment of the invention aims to provide a method and a system for improving indoor language definition, which can effectively improve the indoor language definition.

To achieve the above object, an embodiment of the present invention provides a method for improving indoor speech intelligibility, including:

acquiring the geometric dimension of an indoor building, and establishing an indoor simulation model according to the geometric dimension;

selecting a plurality of parameter evaluation points in the indoor simulation model, and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

calculating the average reverberation time of the definition weak points in an octave frequency band;

calculating a sound absorption increment corresponding to the octave frequency band according to preset target reverberation time and the average reverberation time of the octave frequency band;

selecting a sound absorbing material according to the sound absorption increment; wherein the sound absorbing material is adapted to be arranged at a first predetermined position within a room.

As an improvement of the above, after the diffuser, the reflective material and the sound absorbing material are arranged in the room, the method further comprises:

selecting a plurality of definition weak points from the parameter evaluation points according to a preset definition evaluation parameter calculation strategy;

judging whether the current definition weak point is the same as the definition weak point obtained by the last calculation;

if yes, taking the current definition weak point as a reference position for arranging the reflecting material indoors; if not, the current point of weakness of the definition is taken as a reference location for arranging the diffuser and reflective material within the chamber.

As an improvement of the above, after the diffuser, the reflective material and the sound absorbing material are arranged in the room, the method further comprises:

acquiring the background noise level at the sharpness weak point;

acquiring a sound pressure level at the definition weak point when a sound is emitted at a sound source position preset indoors;

calculating a signal-to-noise ratio from the background noise level and the sound pressure level;

and when the sound pressure level is smaller than a preset first threshold or the signal-to-noise ratio is smaller than a preset second threshold, judging that sound amplifying equipment needs to be installed at a second preset position in the room.

As an improvement of the above scheme, the selecting a plurality of sharpness weak points from the parameter evaluation points according to a preset sharpness evaluation parameter calculation strategy includes:

calculating the impulse response of the parameter evaluation point;

calculating an initial evaluation parameter of each parameter evaluation point under the selected octave frequency band according to the impulse response;

calculating an initial evaluation parameter mean value of each parameter evaluation point as a definition evaluation parameter of the parameter evaluation point;

and acquiring a plurality of parameter evaluation points with the minimum definition evaluation parameter as definition weak points.

As an improvement of the above solution, if the indoor building is a building with seats, then selecting a plurality of parameter evaluation points in the indoor simulation model includes:

and uniformly selecting a plurality of parameter evaluation points in the seats in the indoor simulation model.

As an improvement of the above scheme, the sound absorption material comprises a medium-low frequency sound absorption material and a medium-high frequency sound absorption material, and the first preset position comprises a rear wall of the indoor building, an included angle between a ceiling and a side wall of the indoor building, and a junction between a front wall and the side wall; the middle-low frequency sound absorption material is used for being arranged on the rear wall of the indoor building, and the middle-high frequency sound absorption material is used for being arranged at the corner between the ceiling and the side wall of the indoor building and the junction between the front wall and the side wall.

As an improvement of the above solution, the reflective material is arranged at a ceiling position corresponding to the weak point of sharpness; wherein the reflective material is arranged according to a preset reflective material arrangement strategy.

As an improvement of the above, the reflective material arrangement strategy comprises:

calculating a direct sound path from an indoor preset sound source position to a listener position;

calculating a first reflected acoustic path from the reflective material at the acoustic source location;

calculating a second reflected acoustic path with the reflective material at the listener position;

calculating an included angle between the second reflected sound path and the direct sound path and a reflected sound delay time according to the direct sound path, the first reflected sound path and the second reflected sound path;

adjusting the inclination between the reflecting material and the horizontal plane of the ceiling until the included angle is less than or equal to a preset included angle threshold value and the reflected sound delay time is less than or equal to a preset delay time threshold value.

In order to achieve the above object, an embodiment of the present invention further provides a system for improving indoor speech intelligibility, including:

the simulation model establishing module is used for acquiring the geometric dimension of an indoor building and establishing an indoor simulation model according to the geometric dimension;

the definition weak point acquisition module is used for selecting a plurality of parameter evaluation points in the indoor simulation model and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

the mean reverberation time calculation module is used for calculating the mean reverberation time of the definition weak points in the selected octave frequency band;

the sound absorption increment calculation module is used for calculating a sound absorption increment corresponding to the octave frequency band according to the preset target reverberation time and the average reverberation time of the octave frequency band;

the sound absorption material acquisition module is used for selecting a sound absorption material according to the sound absorption increment; wherein the sound absorbing material is adapted to be arranged at a first predetermined position within a room.

As an improvement of the above, after the diffuser, the reflective material and the sound absorbing material are arranged in the room, the system further includes:

a background noise level measurement acquisition module for acquiring a background noise level at the sharpness weak point;

a sound pressure level acquisition module for acquiring a sound pressure level at the clarity weak point when a sound is emitted at a sound source position preset indoors;

the signal-to-noise ratio calculation module calculates a signal-to-noise ratio according to the background noise level and the sound pressure level;

and the comparison module is used for judging that sound amplifying equipment needs to be installed at a second preset position in the room when the sound pressure level is smaller than a preset first threshold or the signal-to-noise ratio is smaller than a preset second threshold.

Compared with the prior art, the method and the system for improving the indoor language definition disclosed by the embodiment of the invention have the advantages that the weak position of the language definition is screened in a targeted manner, the diffuser and the reflecting material are arranged by taking the weak position of the language definition as a reference position, the sound absorption increment is calculated according to the reverberation time, the corresponding sound absorption material is selected according to the sound absorption increment, the sound absorption material is arranged at the first preset position in the room, and the indoor language definition can be effectively improved by enhancing the useful sound energy and the useful early reflected sound at the weak position of the language definition. The method and the system for improving the indoor language definition, disclosed by the embodiment of the invention, have higher economical efficiency and reduce unnecessary cost compared with the method of arranging more sound-absorbing materials in a classroom as much as possible, because the useful early reflected sound and the useful sound energy in the reflected sound are utilized, the reverberation sound energy is reduced by the sound-absorbing materials, the useful sound energy and the useful early reflected sound are improved by the reflecting materials, and compared with the method for directly installing the sound amplification system, the method and the system make up for some defects, such as the problem of sound exhaustion of a teacher caused by too low volume due to the fact that the total sound pressure level of the teacher is reduced by arranging more sound-absorbing materials, and the problem of sound energy ratio which cannot be solved by the sound amplification system. Compared with the prior art, the method is more targeted, and the method has a large promotion range on the language definition of the weak position of the language definition.

Drawings

Fig. 1 is a flowchart of a method for improving indoor speech intelligibility according to an embodiment of the present invention;

FIG. 2 is a graphical representation of the sound absorption coefficient versus frequency of a sound absorbent provided by an embodiment of the present invention;

FIG. 3 is a schematic view of a low frequency sound absorbing material in an indoor arrangement provided by an embodiment of the present invention;

FIG. 4 is a schematic illustration of a high frequency sound absorbing material provided by an embodiment of the present invention in an indoor arrangement;

FIG. 5 is a schematic illustration of another high frequency sound absorbing material provided by embodiments of the present invention in an indoor arrangement;

FIG. 6 is a schematic view of a reflective material disposed within a chamber as provided by an embodiment of the present invention;

fig. 7 is a schematic view of an arrangement of a sound reinforcement device in a room according to an embodiment of the present invention;

fig. 8 is another schematic view of an indoor sound reinforcement device provided by an embodiment of the present invention;

FIG. 9 is a flowchart of another method for improving indoor speech intelligibility according to an embodiment of the present invention;

fig. 10 is a block diagram illustrating an architecture of a system for enhancing indoor speech intelligibility according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a flowchart of a method for improving indoor speech intelligibility according to an embodiment of the present invention; the method for improving indoor language definition comprises the following steps:

s1, acquiring the geometric dimension of the indoor building, and establishing an indoor simulation model according to the geometric dimension;

s2, selecting a plurality of parameter evaluation points in the indoor simulation model, and selecting a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation strategy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

s3, measuring the octave reverberation time of the definition weak point in the scene, and calculating the average reverberation time of the definition weak point in the octave frequency band;

s4, calculating a sound absorption increment corresponding to the octave frequency band according to the preset target reverberation time and the average reverberation time of the octave frequency band;

s5, selecting a sound absorption material according to the sound absorption increment; wherein the sound absorbing material is adapted to be arranged at a first predetermined position within a room.

It should be noted that the indoor building according to the embodiment of the present invention is a building provided with a seat and a platform, such as a classroom, a conference room, and the like.

Specifically, in step S1, the indoor building geometry is measured, the length, width and height are L, W, H, and for a stairway classroom, the height is measured in two, namely classroom front height H1 and classroom rear height H2. Further, the volume V of the indoor building is calculated. And establishing an indoor simulation model of the indoor building by using simulation software according to the geometric dimension and the volume.

Specifically, in step S2, M parameter evaluation points are uniformly selected in the seats in the indoor simulation model, wherein M is larger than or equal to 12. And selecting a plurality of definition weak points from the parameter evaluation points according to a preset definition evaluation parameter calculation strategy, wherein the method comprises the steps of S21-S24.

And S21, calculating the impulse response of the parameter evaluation point. Illustratively, the impulse responses h of the M parameter evaluation points are respectively calculated by acoustic simulation software_i(n), i ═ 1, 2.., M,; wherein n is a sampling point of a time axis, and n is more than or equal to 1.

S22, calculating initial evaluation parameters of each parameter evaluation point in the selected 2 octave frequency bands according to the impulse response; wherein, the octave frequency band is 250Hz and 500 Hz. The initial evaluation parameters satisfy the following formula:

wherein, C₃₀For the initial evaluation parameter, n₃₀Number of sampling points at 30ms, e.g. when pulsedWhen the sampling frequency of the response is 48000Hz, n₃₀＝1440。

S23, calculating the mean value of the initial evaluation parameters of each parameter evaluation point as the definition evaluation parameters of the parameter evaluation points, namely calculating C of 250Hz and 500Hz octave frequency bands₃₀Mean value ofThe following formula is satisfied:

and S24, acquiring a plurality of parameter evaluation points with the minimum definition evaluation parameter as definition weak points. Illustratively, the mean value is obtainedThe minimum 3 points are the sharpness weaknesses.

Specifically, in step S3, the octave band reverberation times RT of the 3 points of weakness of sharpness are measured in the field_f(i) (ii) a Wherein i represents the ith sharpness weakness point, i is 1,2, 3; f denotes the center frequency of the respective octaves, and f is 125Hz,250Hz,500Hz,1000Hz,2000Hz,4000Hz,8000 Hz. It should be noted that the reverberation time refers to the time that the sound pressure level drops by 60db after the sound source stops sounding after the indoor sound field becomes stable, and is measured in the actual indoor building by the test instrument in the embodiment of the present invention. Then, the average reverberation time of the 7 octave bands of the 3 weak points of sharpness is calculated, satisfying the following formula:

specifically, in step S4, a target reverberation time RT for each frequency interval is determined_GfTarget reverberation time RT with octave frequency band f equal to 500Hz_G500For reference, 0.6s < RT is set_G500And < 0.8s, setting the target reverberation time of each octave as follows:

RT_Gf＝a×RT_G500formula (4);

wherein, when the central frequency f is 125 Hz-250 Hz, the coefficient a is 1.0-1.2. When the central frequency f is 500Hz to 8000Hz, the coefficient a is 0.9 to 1.0.

Calculating the sound absorption increment corresponding to the octave frequency band according to the preset target reverberation time and the average reverberation time of the octave frequency band, and satisfying the following formula:

wherein, Delta A_fAnd V is the sound absorption increment of the octave frequency band, and is the volume of the indoor building.

Specifically, in step S5, the selecting the sound absorbing material according to the sound absorption increment includes:

and S51, selecting proper sound absorption materials and areas thereof according to the sound absorption increment, wherein the sound absorption materials can be one or more, so that the total sound absorption quantity of the selected sound absorption materials in each octave frequency band is more than or equal to the sound absorption increment of each octave frequency band. The sound absorption quantity of each sound absorption material in each octave frequency band is calculated by the following formula:

wherein A is_fIs the sound absorption amount of the sound absorption material in an octave frequency band with the center frequency f, a_fIs the sound absorption coefficient of the sound absorption material in an octave frequency band with a center frequency f,is the surface area of the sound absorbing material;

and S52, selecting a proper sound absorption material according to the sound absorption increment.

Optionally, the sound absorbing material comprises a medium-low frequency sound absorbing material and a medium-high frequency sound absorbing material; under the condition of calculating the sound absorption increment to be increased in each frequency range, a proper sound absorption material can be selected from sound absorption materials such as medium-high frequency sound absorption materials, medium-low frequency sound absorption materials and the like according to the size of the sound absorption increment to be increased in each frequency range, wherein the medium-high frequency sound absorption materials comprise glass wool felts and the like, and the medium-low frequency sound absorption materials comprise asbestos cement perforated plates and the like. The first preset position comprises a rear wall of the indoor building, an included angle between a ceiling and a side wall of the indoor building, and a junction of a front wall and the side wall.

For example, referring to fig. 2, fig. 2 is a graph illustrating the sound absorption coefficient versus frequency of a sound absorbing material provided by an embodiment of the present invention, and the sound absorbing material can be selected according to the average sound absorption coefficient and the frequency.

Referring to fig. 3, the middle and low frequency sound absorbing material is arranged on a rear wall of the indoor building, for example, the middle and low frequency sound absorbing material can be arranged on a position 30cm (centimeter) above a height position from the ground to an indoor preset sound source position in the rear wall, and the sound source position is a platform. Referring to fig. 4 and 5, the medium-high frequency sound absorbing material is arranged at an included angle between a ceiling and a side wall of the indoor building and a junction between a front wall and the side wall, and the width of the sound absorbing material arranged at the junction is 40cm to 60 cm.

Specifically, the weak points of clarity are used as reference positions for arranging the diffusers in the room, and the diffusers (which should be mainly effective for sound with a frequency of 500Hz or less) are arranged by taking the side walls on both sides of the reference positions (positions with the same height as the listener seat) as the center, wherein the length of the diffusers should be 1.5m to 3m, and the height should be 1m to 1.5 m. The default values are set to 2m long and 1m high. The diffuser can diffuse sound away to make sound spread more uniformly in space, and the surface of the diffuser is uneven, such as a wooden diffuser, a three-dimensional diffuser and the like.

In particular, the weak points of clarity are used as reference points for arranging reflective material in the room, which is a material that reflects most of the sound, such as solid wood boards, walls, glass, etc., generally solid wood boards with high stiffness. Sound reflections are reflected like light rays by mirrors.

Optionally, the reflective material is arranged at a ceiling position corresponding to the weak point of sharpness; wherein the reflective material is arranged according to a preset reflective material arrangement strategy. As shown in FIG. 6, the reflective material arrangement strategy includes S101-S105:

s101, calculating a direct sound path from a sound source position preset indoors to a listener position;

s102, calculating a first reflected sound path between the sound source position and the reflecting material;

s103, calculating a second reflected sound path between the listener position and the reflecting material;

s104, calculating an included angle between the second reflected sound path and the direct sound path and reflected sound delay time according to the direct sound path, the first reflected sound path and the second reflected sound path;

the included angle satisfies the following formula:

wherein θ is the angle α_DFor the direct sound path, α_R1For the first reflected acoustic path, α_R2Is the second reflected acoustic path;

the reflected sound delay time satisfies the following formula:

wherein Δ t is the reflected sound delay time, and c is the sound velocity;

s105, adjusting the inclination between the reflecting material and the horizontal plane of the ceiling until the included angle is smaller than or equal to a preset included angle threshold value and the delay time of the reflected sound is smaller than or equal to a preset delay time threshold value.

Further, after the diffuser, the reflective material and the sound absorbing material are disposed indoors, the method further includes steps S6 to S8:

s6, selecting a plurality of definition weak points from the parameter evaluation points according to a preset definition evaluation parameter calculation strategy;

s7, judging whether the current definition weak point is the same as the definition weak point obtained by the last calculation;

s8, if yes, taking the current definition weak point as a reference position for arranging the reflecting material in the room; if not, the current point of weakness of the definition is taken as a reference location for arranging the diffuser and reflective material within the chamber.

Specifically, if the current definition weak point is the same as the definition weak point obtained by the previous calculation, the reflecting materials are arranged by taking the upper half parts of the side walls at the two sides and the upper half part of the rear wall (the upper half part is positioned 30cm above the listener position to the position where the wall is connected with the ceiling) at the positions as the centers. According to the steps S101-S105, the inclination of the reflecting material needs to be adjusted until the included angle theta between the second reflected sound path and the horizontal plane where the direct sound path is located is less than or equal to 30 degrees and the delay time delta t of the reflected sound is less than or equal to 30 ms. If the current definition weak point is different from the definition weak point obtained by the previous calculation, the current definition weak point is still processed by the same method, and the current definition weak point is taken as a reference position for arranging the diffuser and the reflective material indoors, namely, the above mentioned manner of arranging the diffuser and the reflective material is adopted, and the details are not repeated herein.

Further, after the diffuser, the reflective material and the sound absorbing material are disposed indoors, the method further includes steps S9 to S12:

s9, acquiring the background noise level N at the definition weak point;

s10, acquiring the weak point of clearness when a sound is emitted at a sound source position preset in the room (such as a person talking on a platform)The sound pressure level SPL of; the following formula is satisfied:

wherein Q is the directivity factor of the sound source (human presence platform)When speaking, the Q value is generally 1), r is the distance from the sound source to the listener, S is the internal surface area of the indoor building,for the average sound absorption coefficient of the indoor building, SWL is the sound power level when a person speaks, and is calculated as follows:

wherein, w₀＝10^-12w (watt) is reference power, w is the acoustic power when a person speaks, for example, the acoustic power when a teacher speaks a class is about 50 μ w;

s11, calculating the SNR according to the background noise level and the sound pressure level, and satisfying the following formula:

SNR ═ SPL-N formula (11);

and S12, when the sound pressure level is smaller than a preset first threshold value or the signal-to-noise ratio is smaller than a preset second threshold value, judging that sound amplifying equipment needs to be installed at a second preset position in the room. Illustratively, the sound reinforcement device is a speaker.

Specifically, the first threshold is 60dB, the second threshold is 15dB, if SPL is less than 60dB or SNR is less than 15dB, two speakers are installed above the first row of seats (i.e. the second predetermined position), the distance between the two speakers and the left and right walls is 1/4 of the classroom width, and the main axes of the speakers point forward and point forwardThe row of seats in which the minimum position is located. The frequency response range of the sound amplification system is between 100Hz and 12000 Hz. The loudspeaker is mounted schematically as shown in figure 7 in plan view and figure 8 in cross-section.

Further, the process of the above steps S1-S12 can refer to FIG. 9.

Compared with the prior art, the method for improving the indoor language definition disclosed by the embodiment of the invention has the advantages that the weak position of the language definition is screened in a targeted manner, the diffuser and the reflecting material are arranged by taking the weak position of the language definition as a reference position, the sound absorption increment is calculated according to the reverberation time, the corresponding sound absorption material is selected according to the sound absorption increment, the sound absorption material is arranged at the first preset position in the room, and the indoor language definition can be effectively improved by enhancing the useful sound energy and the useful early reflected sound at the weak position of the language definition. The method for improving the indoor language definition disclosed by the embodiment of the invention has better economical efficiency and reduces unnecessary cost compared with the method for arranging more sound-absorbing materials in a classroom as much as possible, because the useful early reflected sound and the useful sound energy in the reflected sound are utilized, the sound-absorbing materials are used for reducing the reverberation sound energy, and the reflecting materials are used for improving the useful sound energy and the useful early reflected sound. Compared with the prior art, the method is more targeted, and the method has a large promotion range on the language definition of the weak position of the language definition.

Referring to fig. 10, fig. 10 is a block diagram illustrating a system 10 for enhancing indoor speech intelligibility according to an embodiment of the present invention, where the system 10 for enhancing indoor speech intelligibility includes:

the simulation model establishing module 11 is used for acquiring the geometric dimension of an indoor building and establishing an indoor simulation model according to the geometric dimension;

a definition weak point obtaining module 12, configured to select a plurality of parameter evaluation points in the indoor simulation model, and select a plurality of definition weak points in the parameter evaluation points according to a preset definition evaluation parameter calculation policy; wherein the point of weakness is used as a reference location for positioning a diffuser and reflective material within the chamber;

an average reverberation time calculation module 13, configured to calculate an average reverberation time of the sharpness weak point in the octave frequency band;

the sound absorption increment calculation module 14 is configured to calculate a sound absorption increment corresponding to the octave frequency band according to a preset target reverberation time and the average reverberation time of the octave frequency band;

a sound absorbing material obtaining module 15 for selecting a sound absorbing material according to the sound absorbing increment; wherein the sound absorbing material is for being arranged at a first preset position in a room;

a background noise level measurement acquisition module 16 for acquiring a background noise level at the sharpness weak point;

a sound pressure level acquiring module 17 configured to acquire a sound pressure level at the clarity weak point when a sound is emitted at a sound source position preset indoors;

a signal-to-noise ratio calculation module 18 for calculating a signal-to-noise ratio based on the background noise level and the sound pressure level;

and the comparison module 19 is configured to determine that the sound reinforcement device needs to be installed at a second preset position in the room when the sound pressure level is smaller than a preset first threshold or the signal-to-noise ratio is smaller than a preset second threshold.

Optionally, if the indoor building is a building provided with a seat, the sharpness weak point obtaining module 12 is specifically configured to:

and uniformly selecting a plurality of parameter evaluation points in the seats in the indoor simulation model.

Optionally, the sharpness vulnerability acquisition module 12 is specifically configured to:

calculating the impulse response of the parameter evaluation point; calculating an initial evaluation parameter of each parameter evaluation point under an octave frequency band according to the impulse response; calculating an initial evaluation parameter mean value of each parameter evaluation point as a definition evaluation parameter of the parameter evaluation point; and acquiring a plurality of parameter evaluation points with the minimum definition evaluation parameter as definition weak points.

Optionally, the sound absorbing material obtaining module 15 is specifically configured to:

calculating an average sound absorption coefficient according to the sound absorption increment and the inner surface area of the indoor building; and selecting the corresponding sound absorption material according to the average sound absorption coefficient.

Optionally, the sound absorbing material includes a middle-low frequency sound absorbing material and a middle-high frequency sound absorbing material, and the first preset position includes a rear wall of the indoor building, an included angle between a ceiling and a side wall of the indoor building, and a junction between a front wall and the side wall; the middle-low frequency sound absorption material is used for being arranged on the rear wall of the indoor building, and the middle-high frequency sound absorption material is used for being arranged at the corner between the ceiling and the side wall of the indoor building and the junction between the front wall and the side wall.

Optionally, the reflective material is arranged at a ceiling position corresponding to the weak point of sharpness; the reflecting materials are arranged according to a preset reflecting material arrangement strategy; the reflective material placement strategy includes: calculating a direct sound path from an indoor preset sound source position to a listener position; calculating a first reflected acoustic path at the sound source location and the ceiling location; calculating a second reflected acoustic path at the listener position from the ceiling position; calculating an included angle between the second reflected sound path and the direct sound path and a reflected sound delay time according to the direct sound path, the first reflected sound path and the second reflected sound path; adjusting the inclination between the reflecting material and the horizontal plane of the ceiling until the included angle is less than or equal to a preset included angle threshold value and the reflected sound delay time is less than or equal to a preset delay time threshold value.

Further, the system further includes a judging module 20, configured to select a plurality of sharpness weaknesses from the parameter evaluation points according to a preset sharpness evaluation parameter calculation strategy, and judge whether the current sharpness weakness is the same as the sharpness weakness calculated last time;

if the current definition weak point is the same as the definition weak point obtained by the last calculation, taking the current definition weak point as a reference position for arranging a reflecting material indoors; and if the current definition weak point is different from the definition weak point obtained by the last calculation, taking the current definition weak point as a reference position for arranging the diffuser and the reflecting material indoors.

It should be noted that, for the working process of the system 10 for improving indoor language definition according to the embodiment of the present invention, reference is made to the working process of the method for improving indoor language definition according to the above embodiment, and details are not repeated herein.

Compared with the prior art, the system for improving the indoor language definition disclosed by the embodiment of the invention can be used for screening the weak position of the language definition in a targeted manner, arranging the diffuser and the reflecting material by taking the weak position of the language definition as a reference position, calculating the sound absorption increment according to the reverberation time, selecting the corresponding sound absorption material according to the sound absorption increment, arranging the sound absorption material at the first preset position in the room, and enhancing the useful sound energy and the useful early reflected sound at the weak position of the language definition, so that the indoor language definition can be effectively improved. The system for improving the indoor language definition is more economical than methods of arranging more sound-absorbing materials in a classroom as much as possible and reduces unnecessary cost, because useful early reflected sound and useful sound energy in the reflected sound are utilized, the sound-absorbing materials are used for reducing reverberation sound energy, and the reflecting materials are used for improving the useful sound energy and the useful early reflected sound. Compared with the prior art, the method is more targeted, and the method has a large promotion range on the language definition of the weak position of the language definition.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.