A method and system for selecting the placement location of a microphone

Abstract

The present application provides a method and system for selecting the placement position of a microphone. A multi-factor acquisition room space model is established by collecting the physical characteristics of a multi-factor acquisition room and the characteristics of wall materials. According to the positions of the person to be collected's seat and the speaker, a sound source and a sound interference source are added to the space model. A microphone array is set according to the positions of the sound source and the sound interference source. The sound source is used to emit a sound signal to excite the microphone array, and the output signal of the microphone array is obtained. The transfer function of the microphone array is obtained by using the output signal and the sound signal. The flatness and average amplitude of the output signal of the microphone array are obtained according to the transfer function and compared with a comparison microphone array to determine the optimal microphone array setting method.

Description

Technical Field

[0001] This application relates to the technical field of sound collection, and particularly to a method and system for selecting the placement position of microphones. Background Art

[0002] A multi-factor collection room is an enclosed space for collecting various information of the person to be collected. Inside the multi-factor collection room, there are speakers and microphones as communication devices between the collector and the person to be collected. All voice information generated by the communication devices needs to be backed up, and the voice information of the person to be collected is particularly crucial. The setting position of the microphone directly affects the voice quality of the person to be collected. Therefore, it is necessary to find the optimal setting position of the microphone.

[0003] In the multi-factor collection room, the seat of the person to be collected is set at the center of the room, and the speaker is set near the interrogation window. The microphone is set on the storage board of the seat of the person to be collected. However, in this placement method, electromagnetic interference will be formed on the microphone when the speaker emits sound, affecting the sound collection effect of the microphone and being unfavorable for the collection of the voice information of the person to be collected. The speaker, as an energized device, will also form electromagnetic interference on the sound collection effect of the microphone.

[0004] In order to reduce the interference of the speaker on the sound collection effect of the microphone, a directional speaker is used as the device for playing the voice of the collector, reducing the sound wave scattering. At the same time, the microphone is set on the opposite side of the sound wave transmission direction of the directional speaker. This setting method of the microphone and the speaker reduces the influence of the speaker on the sound collection of the microphone. However, in order to better collect the voice information of the person to be collected, the placement method of the microphone still needs to be improved. Summary of the Invention

[0005] This application provides a method and system for selecting the placement position of microphones to solve the problem of difficult collection of the voice information of the person to be collected caused by improper setting of the microphones.

[0006] This application provides a method and system for selecting the placement position of microphones, and its steps include:

[0007] Collect the characteristic information of the multi-factor collection room, and establish a spatial model of the multi-factor collection room according to the characteristic information.

[0008] The characteristic information includes the physical characteristics of the multi-factor collection room. The physical characteristics include the length, width, and height of the multi-factor collection room. A spatial model of the multi-factor collection room can be established according to the length, width, and height of the multi-factor collection room. The characteristic information also includes the wall material information of the multi-factor collection room, which reflects the sound absorption characteristics of the multi-factor collection room, and adds the sound absorption characteristics to the control model.

[0009] The walls of the multi-factor acquisition chamber are built with materials having good sound insulation effects. Using such materials with good sound insulation effects can reduce the sound reflection formed due to the multi-factor acquisition chamber being an enclosed space, which is beneficial to the sound collection of the microphone. Furthermore, it is beneficial to the collection of the voice information of the person being collected. Adding the sound absorption feature to the spatial model is to improve the degree of coincidence between the spatial model and the multi-factor acquisition chamber. The higher the degree of restoration of the multi-factor acquisition chamber by the spatial model, the more accurate the subsequent calculation results will be.

[0010] Set a sound source, a speaker, a microphone array, and a comparison microphone array in the spatial model according to the feature information.

[0011] The feature information further includes the characteristics of the sound wave emitted by the sound source, the characteristics of the sound wave emitted by the speaker, and the sound collection characteristics of the microphone array and the comparison microphone array. Based on the various characteristics, confirm the primary setting positions of the sound source, the speaker, the microphone array, and the comparison microphone array.

[0012] Use the sound source to emit a sound signal to excite the microphone array and the comparison microphone array, and calculate the transfer functions of the microphone array and the comparison microphone array.

[0013] The sound signal emitted by the sound source is equivalent to the sound emitted by the person being collected. Both the microphone array and the comparison microphone array can respond to the sound signal emitted by the sound source. Using the response and the sound signal, the response capabilities of the microphone array and the comparison microphone array to the sound signal can be obtained.

[0014] According to the transfer function of the microphone array and the transfer function of the comparison microphone array, calculate the placement evaluation factors of the microphone array and obtain the values of the placement evaluation factors.

[0015] The placement evaluation factors include unevenness and average amplitude difference. Among them, the unevenness reflects the smoothness of the output signal. The average amplitude difference reflects the attenuation degree of the output signal.

[0016] Compare the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method.

[0017] The smaller the unevenness, the better the stability of the output signal. The larger the average amplitude difference, the gap between the output signal amplitudes of the microphone array and the comparison microphone array can be compared, and the microphone array with a larger output amplitude can be obtained, thereby determining the microphone array with a smaller attenuation degree of the output signal. Conduct a comprehensive evaluation of the unevenness and the average amplitude difference to obtain the optimal microphone array setting method.

[0018] Set the position of the microphone array according to the optimal microphone array method.

[0019] After obtaining the optimal microphone array setting method, the sound components inside the multi-factor acquisition chamber can be set according to the sound source, speaker, and the optimal microphone array setting method in the spatial model.

[0020] The primary step in calculating the optimal setting method of the microphone array should be to establish the spatial model of the multi-factor acquisition chamber, restore the multi-factor acquisition chamber through the spatial model, and further describe the spatial model by adding feature information related to the multi-factor acquisition chamber to the spatial model.

[0021] Optionally, the steps of collecting the feature information of the multi-factor acquisition chamber and establishing the spatial model of the multi-factor acquisition chamber according to the feature information include:

[0022] Collect the physical features of the multi-factor acquisition chamber, where the physical features include the length, width, and height of the multi-factor acquisition chamber, and establish the spatial model of the multi-factor acquisition chamber according to the length, width, and height of the multi-factor acquisition chamber.

[0023] Collect the wall material information of the multi-factor acquisition chamber, obtain the sound absorption characteristics of the multi-factor acquisition chamber, and add the sound absorption characteristics to the spatial model.

[0024] After adding features to the spatial model, preliminarily set the sound source, speaker, and microphone array in the multi-factor acquisition chamber according to the working principles and characteristics of the internal components in the multi-factor acquisition chamber.

[0025] Optionally, the steps of setting the sound source, speaker, microphone array, and comparison microphone array in the spatial model according to the feature information include:

[0026] Extract the coverage range of the sound waves emitted by the speaker according to the sound emission characteristics of the speaker, and set the sound source and the speaker in parallel in the spatial model.

[0027] Set the microphone array and the comparison microphone array in an area that does not overlap with the coverage range of the sound waves emitted by the speaker according to the coverage range of the sound waves emitted by the speaker.

[0028] After preliminarily setting the sound source, the microphone array, the comparison microphone array, and the speaker, start using the sound source to emit a sound signal, stimulate the microphone array and the comparison microphone array, and judge the optimal setting position of the microphone array based on the output responses of the microphone array and the comparison microphone array.

[0029] Optionally, the steps of using a sound source to emit a sound signal to excite the microphone array and the comparison microphone array and calculating the transfer functions of the microphone array and the comparison microphone array include:

[0030] Use the sound source to emit a sound to excite the microphone array and the comparison microphone array to obtain the output response of the microphone array and the output response of the comparison microphone array.

[0031] Obtain the ratio of the output response of the microphone array to the sound signal to obtain the transfer function of the microphone array.

[0032] Obtain the ratio of the output response of the comparison microphone array to the sound signal to obtain the transfer function of the comparison microphone array.

[0033] After obtaining the transfer functions of the microphone array and the comparison microphone array, the output signals of the microphone array and the comparison microphone array can be evaluated according to the transfer functions. The evaluation method is to evaluate from two aspects: the flatness and the average amplitude of the output signal. There is an average amplitude difference between the average amplitudes of the microphone array and the comparison microphone array. The magnitude of the average amplitude can be judged by the positive or negative value of the average amplitude difference.

[0034] Optionally, the steps of calculating the placement evaluation factor of the microphone array according to the transfer function of the microphone array and the transfer function of the comparison microphone array to obtain the value of the placement evaluation factor include:

[0035] According to the transfer function of the microphone array, obtain the flatness of the transfer function of the microphone array.

[0036] According to the transfer function of the comparison microphone array, obtain the flatness of the transfer function of the comparison microphone array.

[0037] According to the transfer function of the microphone array and the transfer function of the comparison microphone array, obtain the average amplitude difference.

[0038] Optionally, the steps of obtaining the flatness of the transfer function of the microphone array according to the transfer function of the microphone array include:

[0039] Select frequency points in the transfer function of the microphone array and obtain the amplitudes corresponding to the frequency points.

[0040] Calculate the average value of the amplitudes corresponding to the frequency points.

[0041] Substitute the amplitude corresponding to the frequency point, the average value of the amplitudes corresponding to the frequency points, and the number of selected frequency points into the flatness calculation formula to obtain the flatness of the transfer function of the microphone array; the flatness calculation formula is:

[0042]

[0043] where v is the flatness; x is the amplitude corresponding to the frequency point; u is the average value of the amplitudes corresponding to the frequency points; N is the number of selected frequency points.

[0044] Optionally, according to the transfer function of the microphone array and the transfer function of the comparison microphone array, the steps of obtaining the average amplitude difference include:

[0045] Select the highest frequency f from the transfer functions of the microphone array and the comparison microphone array max .

[0046] Set the frequency step Δf of the transfer function of the microphone array.

[0047] Substitute the highest frequency f max and the frequency step into the average amplitude difference calculation formula to obtain the average amplitude difference; the average amplitude difference calculation formula is:

[0048]

[0049] where U is the average amplitude difference; f max is the highest frequency; Δf is the frequency step; a iy is the transfer function amplitude of the i-th microphone on the microphone array at frequency y; b iy is the transfer function amplitude of the i-th microphone on the comparison microphone array at frequency y.

[0050] After obtaining the flatness and the average amplitude difference, evaluate the output signals of the microphone array and the comparison microphone array according to the numerical magnitudes of the flatness and the average amplitude difference, so as to obtain the optimal microphone array setting method.

[0051] Optionally, the steps of comparing the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method include:

[0052] Compare the flatness of the microphone array and the flatness of the comparison microphone array. If the flatness of the microphone array is less than the flatness of the comparison microphone array, it is determined that the placement position of the microphone array is a sub-optimal placement position.

[0053] If the average amplitude difference is a positive number, the placement position of the microphone array is the optimal placement position of the microphone array.

[0054] If the average amplitude difference is a negative number, then a weighted processing is performed on the flatness and the average amplitude difference to obtain a placement position score.

[0055] If the placement position score of the microphone array is greater than the placement position score of the comparison microphone array, it is determined that the placement position of the microphone array is the optimal placement position of the microphone array.

[0056] After obtaining the optimal placement position of the microphone array, the sound source, the speaker, and the microphone array can be set according to the optimal placement position of the microphone array.

[0057] Optionally, setting the position of the microphone array according to the optimal microphone array method includes: setting the sound source at the geometric center of the multi-factor acquisition chamber. Setting the speaker parallel to the sound source and at the interrogation window. Setting the microphone array perpendicular to the speaker and at the top of the multi-factor acquisition chamber.

[0058] The present application also provides a system for selecting the placement position of a microphone, including: a data acquisition module, a simulation module, an operation module, a data analysis module, and an execution module.

[0059] The data acquisition module is used to collect the characteristic information of the multi-factor acquisition chamber and establish a spatial model of the multi-factor acquisition chamber according to the characteristic information.

[0060] The simulation module is used to set a sound source, a sound interference source, a microphone array, and a comparison microphone array in the spatial model according to the characteristic information.

[0061] The operation module is used to use a sound signal emitted by the sound source to excite the microphone array and the comparison microphone array, and calculate the transfer functions of the microphone array and the comparison microphone array.

[0062] The operation module is also used to calculate the placement evaluation factors of the microphone array according to the transfer function of the microphone array and the transfer function of the comparison microphone array, and obtain the numerical values of the placement evaluation factors.

[0063] The data analysis module is used to compare the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method.

[0064] The execution module is used to set the position of the microphone array according to the optimal microphone array method.

[0065] The present application provides a method and a system for selecting the placement positions of microphones. A spatial model is established to simulate a multi-factor acquisition chamber. According to the working characteristics of the sound source, the speaker, and the microphone array, the placement positions of the sound source, the speaker, and the microphone array are initially set. The sound source is used to emit a sound signal. By evaluating the output signals of the microphone array and the comparison microphone array and comparing them, the optimal placement position of the microphone array is obtained. Finally, the microphone array is set according to the optimal placement position of the microphone array. Description of the Drawings

[0066] To more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0067] Figure 1 It is a flowchart of the method for selecting the placement position of the microphone;

[0068] Figure 2 It is a schematic diagram of the steps for establishing the spatial model of the multi-factor acquisition chamber;

[0069] Figure 3 It is a schematic diagram of the steps for initially setting the sound source, the speaker, the microphone array, and the comparison microphone array;

[0070] Figure 4 It is a schematic diagram of the steps for calculating the transfer functions of the microphone array and the comparison microphone array;

[0071] Figure 5 It is a schematic diagram of the steps for calculating the values of the placement evaluation factors;

[0072] Figure 6 It is a schematic diagram of the steps for calculating the unevenness;

[0073] Figure 7 It is a schematic diagram of the steps for calculating the average amplitude difference;

[0074] Figure 8 It is a schematic diagram of the steps for obtaining the optimal microphone array setting method;

[0075] Figure 9 It is a schematic diagram of the optimal microphone array setting method. Detailed Embodiments

[0076] Embodiments will be described in detail below, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following examples do not represent all embodiments consistent with the present application. They are merely examples of systems and methods consistent with some aspects of the present application detailed in the claims.

[0077] The present application provides a method for selecting the placement position of a microphone. The following will be described in detail in conjunction with Figure 1 The steps include:

[0078] Collect the characteristic information of the multi-factor collection room, and establish a spatial model of the multi-factor collection room according to the characteristic information.

[0079] The characteristic information includes the physical characteristics of the multi-factor collection room. The physical characteristics include the length, width, and height of the multi-factor collection room. A spatial model of the multi-factor collection room can be established according to the length, width, and height of the multi-factor collection room. The characteristic information also includes the wall material information of the multi-factor collection room, which reflects the sound absorption characteristics of the multi-factor collection room, and adds the sound absorption characteristics to the control model.

[0080] The walls of the multi-factor collection room are built with materials having good sound insulation effects. Using the materials with good sound insulation effects can reduce the sound reflection formed due to the multi-factor collection room being an enclosed space, which is beneficial to the sound collection of the microphone. Furthermore, it is beneficial to the collection of the voice information of the person being collected. Adding the sound absorption characteristics to the spatial model is to improve the coincidence degree between the spatial model and the multi-factor collection room. The higher the degree of restoration of the spatial model to the multi-factor collection room, the more accurate the subsequent calculation results will be.

[0081] Set a sound source, a speaker, a microphone array, and a comparison microphone array in the spatial model according to the characteristic information.

[0082] The characteristic information also includes the characteristics of the sound waves emitted by the sound source, the characteristics of the sound waves emitted by the speaker, and the sound collection characteristics of the microphone array and the comparison microphone array. Based on the various characteristics, confirm the primary setting positions of the sound source, the speaker, the microphone array, and the comparison microphone array.

[0083] Use the sound source to emit a sound signal to excite the microphone array and the comparison microphone array, and calculate the transfer functions of the microphone array and the comparison microphone array.

[0084]

[0085] ​The sound signal emitted by the sound source is equivalent to the sound emitted by the person being collected. Both the microphone array and the comparison microphone array can respond to the sound signal emitted by the sound source. Using the response and the sound signal, the response capabilities of the microphone array and the comparison microphone array to the sound signal can be obtained.

[0086] According to the transfer function of the microphone array and the transfer function of the comparison microphone array, calculate the placement evaluation factor of the microphone array to obtain the value of the placement evaluation factor.

[0087] The placement evaluation factor includes unevenness and average amplitude difference. The unevenness reflects the smoothness of the output signal. The average amplitude difference reflects the attenuation degree of the output signal.

[0088] Compare the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method.

[0089] The smaller the unevenness, the better the stability of the output signal. The larger the average amplitude difference, the gap between the amplitudes of the output signals of the microphone array and the comparison microphone array can be compared, and the microphone array with a larger output amplitude can be obtained, thereby determining the microphone array with a smaller attenuation degree of the output signal. Conduct a comprehensive evaluation of the unevenness and the average amplitude difference to obtain the optimal microphone array setting method.

[0090] According to the optimal microphone array method, set the position of the microphone array.

[0091] After obtaining the optimal microphone array setting method, the sound components inside the multi-factor acquisition room can be set according to the sound source, speaker, and the optimal microphone array setting method in the space model.

[0092] The basis for obtaining the optimal microphone array setting method is to establish the space model of the multi-factor acquisition room. The higher the degree of restoration of the space model to the multi-factor acquisition room, the more accurate the calculation result. The following combines Figure 2 The steps for establishing the space model of the multi-factor acquisition room are described in detail. The steps include:

[0093] Collect the physical characteristics of the multi-factor acquisition room. The physical characteristics include the length, width, and height of the multi-factor acquisition room. According to the length, width, and height of the multi-factor acquisition room, establish the space model of the multi-factor acquisition room.

[0094] By collecting the length, width, and height of the multi-factor collection chamber, the spatial model of the multi-factor collection chamber is defined, thereby establishing a primary spatial model. In addition, a coordinate system can also be established using the values of the length, width, and height to facilitate the description of the positions of various parts within the spatial model.

[0095] Collect the wall material information of the multi-factor collection chamber to obtain the sound absorption characteristics of the multi-factor collection chamber, and add the sound absorption characteristics to the spatial model.

[0096] The walls of the multi-factor collection chamber are built with materials having good sound insulation effects. Using such materials with good sound insulation effects can reduce the sound reflection formed due to the multi-factor collection chamber being an enclosed space, which is beneficial for the microphone to pick up sound, and thus is beneficial for the collection of the voice information of the person being collected. Adding the sound absorption characteristics to the spatial model is to improve the degree of restoration of the spatial model to the multi-factor collection chamber.

[0097] According to the characteristic information, the positions of the sound source, speaker, microphone array, and comparison microphone array can also be initially set. The characteristic information also includes the sound emission characteristics of the speaker, specifically manifested as the coverage range of the emitted sound waves. The following combines Figure 3 The steps for initially setting the sound source, speaker, and microphone array are described in detail, and the steps include:

[0098] According to the sound emission characteristics of the speaker, extract the coverage range of the sound waves emitted by the speaker, and set the sound source parallel to the speaker within the spatial model.

[0099] The speaker uses a directional speaker to make the direction of the emitted sound waves more concentrated, and is set at the interrogation window. The direction with the strongest sound wave energy is the parallel direction of the sound waves. Therefore, setting the sound source parallel to the directional speaker means that the position of the person being collected is also parallel to the position of the directional speaker.

[0100] According to the coverage range of the sound waves emitted by the speaker, set the microphone array and the comparison microphone array in an area that does not overlap with the coverage range of the sound waves emitted by the speaker.

[0101] The coverage range of the sound waves emitted by the directional speaker will cause a direct signal impact on the microphone array, resulting in electromagnetic interference, thus affecting the sound pickup effect of the microphone array. Therefore, when initially setting the microphone array and the comparison microphone array, set the microphone array and the comparison microphone array to avoid the sound wave coverage range of the directional speaker. The microphone array and the comparison microphone array can be set perpendicular to the directional speaker, or can be set on a plane at an inclined angle of 30°, 45°, 60°, etc. with respect to the directional speaker.

[0102] After the preliminary settings of the sound source, the loudspeaker, the microphone array and the comparison microphone array, use the sound source to emit a sound signal to excite the microphone array and the comparison microphone array, and obtain their respective transfer functions through the output signals of the microphone array and the comparison microphone array. The following combines Figure 4 The steps of obtaining the transfer function are described in detail, and the steps include:

[0103] Use the sound source to emit a sound signal to excite the microphone array and the comparison microphone array to obtain the output response of the microphone array and the output response of the comparison microphone array.

[0104] The sound signal emitted by the sound source is used to simulate the speech information of the person to be collected, and the microphone array and the comparison microphone array generate corresponding output signals after being excited.

[0105] Obtain the ratio of the output response of the microphone array to the sound signal to obtain the transfer function of the microphone array.

[0106] Obtain the ratio of the output response of the comparison microphone array to the sound signal to obtain the transfer function of the comparison microphone array.

[0107] After obtaining the transfer function, further select the setting of the microphone array by calculating the placement evaluation factor of the microphone array. The following combines Figure 5 The steps of obtaining the placement evaluation factor are described in detail, and the steps include:

[0108] According to the transfer function of the microphone array, obtain the flatness of the transfer function of the microphone array.

[0109] The flatness is used to describe the stability of the output signal. Numerically, the smaller the flatness, the better the stability of the output signal.

[0110] According to the transfer function of the comparison microphone array, obtain the flatness of the transfer function of the comparison microphone array.

[0111] According to the transfer function of the microphone array and the transfer function of the comparison microphone array, obtain the average amplitude difference.

[0112] The average amplitude difference is used to describe the amplitude relationship between the output signals of the microphone array and the comparison microphone array. A larger amplitude of the output signal indicates a smaller attenuation degree and better sound reducibility.

[0113] The placement evaluation factor includes flatness and average amplitude difference. The following combines Figure 6 andFigure 7 The steps for obtaining the flatness and the average amplitude difference are described in detail respectively. The steps for obtaining the flatness include:

[0114] Select frequency points in the transfer function of the microphone array and obtain the amplitudes corresponding to the frequency points.

[0115] The selection of the frequency points is based on the frequency range of human voice, and the frequency range is from 20 Hz to 20000 Hz. The selection is made at a certain difference, such as differences of 20 Hz, 40 Hz, 60 Hz, etc. The amplitudes are used to substitute into the flatness formula to calculate the flatness and are also used to calculate the average amplitude difference.

[0116] Calculate the average value of the amplitudes corresponding to the frequency points.

[0117] Substitute the amplitudes corresponding to the frequency points, the average value of the amplitudes corresponding to the frequency points, and the number of selected frequency points into the flatness calculation formula to obtain the flatness of the transfer function of the microphone array. The flatness calculation formula is:

[0118]

[0119] where v is the flatness; x is the amplitude corresponding to the frequency point; u is the average value of the amplitudes corresponding to the frequency points; N is the number of selected frequency points.

[0120] The steps for obtaining the average amplitude difference include:

[0121] Select the highest frequency f from the transfer functions of the microphone array and the comparison microphone array max .

[0122] Set the frequency step Δf of the transfer function of the microphone array.

[0123] Substitute the highest frequency f max and the frequency step into the average amplitude difference calculation formula to obtain the average amplitude difference; the average amplitude difference calculation formula is:

[0124]

[0125] where U is the average amplitude difference; f max is the highest frequency; Δf is the frequency step; a iy is the transfer function amplitude of the i-th microphone on the microphone array at frequency y; b iy is the transfer function amplitude of the i-th microphone on the comparison microphone array at frequency y.

[0126] It should be noted that the calculation data of the flatness and the average amplitude difference are both extracted from the output signals of the sub-microphones on the microphone array and the comparison microphone array. The flatness and the average amplitude of the output signals of the sub-microphones are averaged for the overall comparison of the microphone array and the comparison microphone array. It is also possible to compare the output signals of the sub-microphones according to the corresponding numbers, which reflects the strength of the local sound collection capabilities of the microphone array and the comparison microphone array.

[0127] After obtaining the flatness and the average amplitude difference, the optimal microphone array setting method is further selected by combining the value of the flatness and the value of the average amplitude difference. The following combines Figure 8 The steps for selecting the optimal microphone array setting method are described in detail, and the steps include:

[0128] Compare the flatness of the microphone array with the flatness of the comparison microphone array. If the flatness of the microphone array is less than the flatness of the comparison microphone array, it is determined that the placement position of the microphone array is a sub-optimal placement position.

[0129] The specific value of the flatness of the microphone array is the average value of the flatness of the output signals of the sub-microphones in the microphone array. The specific value of the flatness of the comparison microphone is the average value of the flatness of the output signals of the sub-microphones in the comparison microphone array.

[0130] After the microphone array setting method with a small flatness value of the output signal is set as the sub-optimal placement position, the optimal microphone array placement position is selected by comparing the average amplitudes.

[0131] If the average amplitude difference is positive, the placement position of the microphone array is the optimal microphone array placement position.

[0132] Combined with the formula for obtaining the average amplitude difference, if the average amplitude difference is positive, it means that the average amplitude of the output signal of the microphone array is greater than the average amplitude of the output signal of the comparison microphone array, that is, the attenuation degree of the output signal of the microphone array is smaller, which indicates that the sound collection effect of the microphone array is better. Combining with the sub-optimal placement position, the placement position of the microphone array can be determined as the optimal placement position.

[0133] If the average amplitude difference is negative, the flatness and the average amplitude difference are weighted to obtain a placement position score.

[0134] If the average amplitude difference is negative, it indicates that the amplitude of the output signal of the microphone array is smaller than that of the output signal of the comparison microphone array. When the microphone array and the comparison microphone array each have advantages, in order to select the optimal placement position of the microphone, it is necessary to weight the results of the flatness and the average amplitude difference, calculate the placement position score, and confirm the optimal placement position by comparing the placement position scores.

[0135] If the placement position score of the microphone array is greater than the placement position score of the comparison microphone array, it is determined that the placement position of the microphone array is the optimal placement position of the microphone array.

[0136] Combine Figure 9 A detailed description of the optimal placement position of the microphone array is given. After obtaining the final placement position of the microphone array, the sound source, the speaker, and the microphone array can be arranged according to the simulation results. The specific arrangement method is as follows: The sound source 3 is set at the geometric center of the multi-factor acquisition chamber. The sound source in the multi-factor acquisition chamber is replaced by the seat of the person being collected, that is, the person being collected is used as the sound source. The speaker 2 is set parallel to the sound source and is set at the interrogation window. The microphone array 1 is set perpendicular to the speaker and is set at the top of the multi-factor acquisition chamber. The controller 4 is used for data acquisition, analysis, storage, and other work.

[0137] This application also provides a system for selecting the placement position of a microphone, including a data acquisition module, a simulation module, an operation module, a data analysis module, and an execution module.

[0138] The data acquisition module is used to collect the characteristic information of the multi-factor acquisition chamber and establish a spatial model of the multi-factor acquisition chamber according to the characteristic information.

[0139] The simulation module is used to set a sound source, a sound interference source, a microphone array, and a comparison microphone array in the spatial model according to the characteristic information.

[0140] The operation module is used to use the sound signal emitted by the sound source to excite the microphone array and the comparison microphone array, and calculate the transfer functions of the microphone array and the comparison microphone array.

[0141] The operation module is also used to calculate the placement evaluation factors of the microphone array according to the transfer function of the microphone array and the transfer function of the comparison microphone array, and obtain the numerical values of the placement evaluation factors.

[0142] The data analysis module is used to compare the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal setting method of the microphone array.

[0143] The execution module is used to set the position of the microphone array according to the optimal microphone array mode.

[0144] This application provides a method and system for selecting the placement position of microphones. A multi-factor acquisition room space model is established by collecting the physical characteristics and wall material characteristics of the multi-factor acquisition room. According to the positions of the person to be acquired's seat and the speaker, a sound source and a sound interference source are added to the space model. The microphone array is set according to the positions of the sound source and the sound interference source. The sound source emits a sound signal to excite the microphone array, and the output signal of the microphone array is obtained. The transfer function of the microphone array is obtained by using the output signal and the sound signal. The flatness and average amplitude of the output signal of the microphone array are obtained according to the transfer function and compared with a comparison microphone array to determine the optimal microphone array setting mode.

[0145] For the similar parts between the embodiments provided in this application, reference can be made to each other. The specific embodiments provided above are only several examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation manner extended based on the solution of this application without creative efforts belongs to the protection scope of this application.

Claims

1. A method for selecting the placement position of a microphone, characterized in that, comprising: collecting the characteristic information of a multi-factor acquisition room, and establishing a spatial model of the multi-factor acquisition room according to the characteristic information; the characteristic information includes the sound emission characteristics of a speaker; setting a sound source, a speaker, a microphone array, a comparison microphone array and the sound emission characteristics of the speaker in the spatial model according to the characteristic information; the step of setting a sound source, a speaker, a microphone array, a comparison microphone array and the sound emission characteristics of the speaker in the spatial model according to the characteristic information includes: extracting the coverage range of the sound wave emitted by the speaker according to the sound emission characteristics of the speaker, and arranging the sound source and the speaker in parallel in the spatial model; according to the coverage range of the sound wave emitted by the speaker, arranging the microphone array and the comparison microphone array in an area that does not coincide with the coverage range of the sound wave emitted by the speaker; using the sound source to emit a sound signal to excite the microphone array and the comparison microphone array, and calculating the transfer functions of the microphone array and the comparison microphone array; calculating the placement evaluation factors of the microphone array according to the transfer function of the microphone array to obtain the numerical values of the placement evaluation factors of the microphone array; and calculating the placement evaluation factors of the comparison microphone array according to the transfer function of the comparison microphone array to obtain the numerical values of the placement evaluation factors of the comparison microphone array; comparing the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method; setting the position of the microphone array according to the optimal microphone setting array method.

2. The method for selecting the placement position of a microphone according to claim 1, characterized in that, the step of collecting the characteristic information of a multi-factor acquisition room and establishing a spatial model of the multi-factor acquisition room according to the characteristic information includes: collecting the physical characteristics of the multi-factor acquisition room, the physical characteristics including the length, width and height of the multi-factor acquisition room, and establishing the spatial model of the multi-factor acquisition room according to the length, width and height of the multi-factor acquisition room; collecting the wall material information of the multi-factor acquisition room to obtain the sound absorption characteristics of the multi-factor acquisition room, and adding the sound absorption characteristics to the spatial model.

3. The method for selecting the placement position of a microphone according to claim 1, characterized in that, the step of using the sound source to emit a sound signal to excite the microphone array and the comparison microphone array and calculating the transfer functions of the microphone array and the comparison microphone array includes: using the sound source to emit a sound signal to excite the microphone array and the comparison microphone array to obtain the output response of the microphone array and the output response of the comparison microphone array; obtaining the ratio of the output response of the microphone array to the sound signal to obtain the transfer function of the microphone array; obtaining the ratio of the output response of the comparison microphone array to the sound signal to obtain the transfer function of the comparison microphone array.

4. The method for selecting the placement position of microphones according to claim 1, wherein the placement evaluation factors include unevenness and average amplitude difference. Characterized in that, The steps of calculating the placement evaluation factors of the microphone array based on the transfer function of the microphone array and the transfer function of the comparison microphone array to obtain the values of the placement evaluation factors include: Obtaining the unevenness of the transfer function of the microphone array according to the transfer function of the microphone array; Obtaining the unevenness of the transfer function of the comparison microphone array according to the transfer function of the comparison microphone array; Obtaining the average amplitude difference according to the transfer function of the microphone array and the transfer function of the comparison microphone array.

5. The method for selecting the placement position of microphones according to claim 4, Characterized in that, The steps of obtaining the unevenness of the transfer function of the microphone array according to the transfer function of the microphone array include: Selecting frequency points in the transfer function of the microphone array and obtaining the amplitudes corresponding to the frequency points; Calculating the average value of the amplitudes corresponding to the frequency points; Substituting the amplitudes corresponding to the frequency points, the average value of the amplitudes corresponding to the frequency points, and the number of selected frequency points into the unevenness calculation formula to obtain the unevenness of the transfer function of the microphone array; the unevenness calculation formula is: ； where v is the unevenness; x is the amplitude corresponding to the frequency point; u is the average value of the amplitudes corresponding to the frequency points; N is the number of selected frequency points.

6. The method for selecting the placement position of microphones according to claim 4, Characterized in that, The steps of obtaining the average amplitude difference according to the transfer function of the microphone array and the transfer function of the comparison microphone array include: Select the highest frequency f from the transfer functions of the microphone array and the comparison microphone array max ; Setting the frequency step Δf of the transfer function of the microphone array; Substitute the highest frequency f max and the frequency step size into the average amplitude difference calculation formula to obtain the average amplitude difference; the average amplitude difference calculation formula is: ； where U is the average amplitude difference; f max is the highest frequency; Δf is the frequency step; a iy is the amplitude of the transfer function of the i-th microphone on the microphone array at frequency y; b iy is the amplitude of the transfer function of the i-th microphone on the comparison microphone array at frequency y.

7. The method for selecting the placement position of microphones according to claim 6, Characterized in that, The steps of comparing the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method include: Comparing the unevenness of the microphone array and the unevenness of the comparison microphone array. If the unevenness of the microphone array is less than the unevenness of the comparison microphone array, it is determined that the placement position of the microphone array is a sub-optimal placement position; If the average amplitude difference is positive, the placement position of the microphone array is the optimal microphone array placement position; If the average amplitude difference is negative, weighted processing is performed on the unevenness and the average amplitude difference to obtain a placement position score; If the placement position score of the microphone array is greater than the placement position score of the comparison microphone array, it is determined that the placement position of the microphone array is the optimal microphone array placement position.

8. The method for selecting the placement position of microphones according to claim 1, Characterized in that, Setting the position of the microphone array according to the optimal microphone array setting method includes: setting the sound source at the geometric center of the multi-factor acquisition chamber; setting the speaker parallel to the sound source and at the interrogation window; setting the microphone array perpendicular to the speaker and at the top of the multi-factor acquisition chamber.

9. A system for selecting the placement position of microphones Characterized in that It includes: A data acquisition module, a simulation module, an operation module, a data analysis module, and an execution module; The data acquisition module is used to acquire the characteristic information of the multi-factor acquisition chamber and establish a spatial model of the multi-factor acquisition chamber according to the characteristic information; the characteristic information includes the sound generation characteristics of the speaker; The simulation module is used to set a sound source, a sound interference source, a microphone array, and a comparison microphone array in the spatial model according to the characteristic information; the steps of setting the sound source, the speaker, the microphone array, the comparison microphone array, and the sound generation characteristics of the speaker in the spatial model according to the characteristic information include: extracting the coverage range of the sound waves emitted by the speaker according to the sound generation characteristics of the speaker, and setting the sound source parallel to the speaker in the spatial model; setting the microphone array and the comparison microphone array in an area that does not overlap with the coverage range of the sound waves emitted by the speaker according to the coverage range of the sound waves emitted by the speaker; The operation module is used to use the sound signal emitted by the sound source to excite the microphone array and the comparison microphone array, and calculate the transfer functions of the microphone array and the comparison microphone array; The operation module is further used to calculate the placement evaluation factors of the microphone array according to the transfer function of the microphone array to obtain the numerical values of the placement evaluation factors of the microphone array; and calculate the placement evaluation factors of the comparison microphone array according to the transfer function of the comparison microphone array to obtain the numerical values of the placement evaluation factors of the comparison microphone array; The data analysis module is used to compare the placement evaluation factors of the microphone array and the comparison microphone array to obtain the optimal microphone array setting method; The execution module is used to set the position of the microphone array according to the optimal microphone array setting method.

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