Sound field reconstruction method, apparatus, system, electronic device, and storage medium

Abstract

The present application relates to the field of audio signal processing, and provides a sound field reconstruction method, device, system, electronic equipment and storage medium, wherein the method comprises: obtaining an original sound source signal collected by a microphone array, the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction; performing ring harmonic decomposition on the original sound source signal to obtain a plurality of ring harmonic components, and performing signal synthesis on the plurality of ring harmonic components to obtain a playing signal of each loudspeaker in a reconstruction area, the playing signal of each loudspeaker being used for sound field reconstruction in the reconstruction area. The sound field reconstruction method, device, system, electronic equipment and storage medium provided by the present application can not only match different sound field reconstruction accuracy requirements, but also ensure that a high-precision sound field is reconstructed at the center of the sound field, and is not limited to accuracy control at certain position points of the center of the sound field, thereby improving the accuracy of sound field reconstruction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of audio signal processing, and in particular to a sound field reconstruction method, device, system, electronic device and storage medium. BACKGROUND

[0002] Noise reconstruction refers to reproducing actual scene noise in a laboratory environment, so that the noise field reconstructed in the laboratory environment is consistent with the target scene sound field, and the measurement indicators include noise source direction, noise spectrum, noise sound pressure level size, etc.

[0003] Noise reconstruction plays a very key role in noisy environment testing, such as voice interaction testing and voice call testing, which usually need to measure the performance of the device in a noise scene, and the accuracy of noise reconstruction will directly affect the accuracy of the test results.

[0004] The existing noise reconstruction technology usually collects noise in the actual scene and stores it, and then plays back the collected noise in the laboratory using a single or multiple loudspeakers, which cannot guarantee the accuracy of the sound field reconstruction. SUMMARY

[0005] The present application provides a sound field reconstruction method, device, system, electronic device and storage medium to solve the defect that the prior art cannot guarantee the accuracy of sound field reconstruction.

[0006] The present application provides a sound field reconstruction method, comprising:

[0007] Obtaining an original sound source signal collected by a microphone array, the array structure of the microphone array being circular, and the number of array elements and the array radius of the microphone array being determined based on the accuracy requirement of sound field reconstruction;

[0008] Performing ring harmonic decomposition on the original sound source signal to obtain a plurality of ring harmonic components, and performing signal synthesis on the plurality of ring harmonic components to obtain a playback signal of each loudspeaker in a reconstruction area, the playback signal of each loudspeaker being used for sound field reconstruction in the reconstruction area.

[0009] According to the sound field reconstruction method provided by the present application, the determination step of the number of array elements and the array radius of the microphone array comprises:

[0010] Determining the accuracy requirement of sound field reconstruction, the accuracy requirement including the reconstruction radius and the upper limit frequency of the reconstruction area;

[0011] Based on the reconstruction radius and the upper limit frequency, determining a number range in which the number of array elements of the microphone array is located;

[0012] Based on the number of array elements of the microphone array and the upper limit frequency, determining a radius range in which the array radius of the microphone array is located.

[0013] According to the sound field reconstruction method provided by the application, the original sound source signal collected by the microphone array is obtained, comprising:

[0014] Based on the accuracy requirement of sound field reconstruction, the target parameters are matched from a plurality of microphone array parameters, including the number range and the radius range;

[0015] The original sound source signal collected by the microphone array corresponding to the target parameters is obtained.

[0016] According to the sound field reconstruction method provided by the application, the original sound source signal collected by the microphone array corresponding to the target parameters is obtained, comprising:

[0017] Based on the target number range and the target radius range in the target parameters, a plurality of microphone arrays are determined, which are concentrically arranged;

[0018] The candidate sound source signals collected by the plurality of microphone arrays are obtained respectively;

[0019] Based on the signal-to-noise ratio and / or signal-to-interference ratio of the candidate sound source signals, the original sound source signals are selected from the candidate sound source signals.

[0020] According to the sound field reconstruction method provided by the application, the plurality of loudspeakers are arranged in a circular array, and the number and array radius of the loudspeakers are determined based on the number of elements and the array radius of the microphone array.

[0021] According to the sound field reconstruction method provided by the application, the determination of the number and array radius of the loudspeakers comprises:

[0022] Based on the number of elements of the microphone array, the maximum order of the microphone array is determined;

[0023] Based on the maximum order of the microphone array, the minimum number of the loudspeakers is determined;

[0024] Based on the maximum order and the array radius of the microphone array, the array radius of the loudspeakers is determined.

[0025] According to the sound field reconstruction method provided by the application, the plurality of ring harmonic components are signal synthesized to obtain the playing signal of each loudspeaker in the reconstruction area, comprising:

[0026] Based on the number and the placement angle of the loudspeakers, the plurality of ring harmonic components are signal synthesized to obtain the playing signal of each loudspeaker in the reconstruction area.

[0027] The application also provides a sound field reconstruction device, comprising:

[0028] The signal acquisition unit is configured to acquire an original sound source signal collected by a microphone array, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction.

[0029] The signal processing unit is configured to perform circular harmonic decomposition on the original sound source signal to obtain a plurality of circular harmonic components, and perform signal synthesis on the plurality of circular harmonic components to obtain a playing signal of each loudspeaker in the reconstruction area, wherein the playing signal of each loudspeaker is used for sound field reconstruction in the reconstruction area.

[0030] The application further provides a sound field reconstruction system, comprising a processor and a plurality of loudspeakers, wherein the processor is connected to each loudspeaker.

[0031] The processor is configured to acquire an original sound source signal collected by a microphone array, perform circular harmonic decomposition on the original sound source signal to obtain a plurality of circular harmonic components, and perform signal synthesis on the plurality of circular harmonic components to obtain a playing signal of each loudspeaker in the reconstruction area, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction.

[0032] The plurality of loudspeakers are configured to play the playing signal.

[0033] The application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the sound field reconstruction method according to any one of the above when executing the program.

[0034] The application further provides a non-transitory computer readable storage medium, which stores a computer program, wherein the computer program is executed by a processor to implement the sound field reconstruction method according to any one of the above.

[0035] The application further provides a computer program product, comprising a computer program, wherein the computer program is executed by a processor to implement the sound field reconstruction method according to any one of the above.

[0036] The sound field reconstruction method, device, system, electronic device and storage medium provided by the application can match different accuracy requirements of sound field reconstruction by designing a microphone array according to the accuracy requirement of sound field reconstruction, and performing circular harmonic decomposition and signal synthesis on an original sound source signal collected by the microphone array to obtain a playing signal of each loudspeaker in a reconstruction area. In addition, the processing method of performing circular harmonic decomposition and signal synthesis on the original sound source signal can ensure that a high-precision sound field is reconstructed at the center of the sound field, and the accuracy control is not limited to some position points in the center of the sound field, thereby improving the accuracy of sound field reconstruction. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to make the technical solutions in the present application or prior art clearer, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0038] Figure 1 is one of the flowcharts of the sound field reconstruction method provided by the present application;

[0039] Figure 2 is another flowchart of the sound field reconstruction method provided by the present application;

[0040] Figure 3 is a flowchart of step 110 in the sound field reconstruction method provided by the present application;

[0041] Figure 4 is a schematic diagram of a multi-circle microphone array provided by the present application;

[0042] Figure 5 is a structural schematic diagram of a sound field reconstruction device provided by the present application;

[0043] Figure 6 is a structural schematic diagram of a sound field reconstruction system provided by the present application;

[0044] Figure 7 is a structural schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0045] In order to make the technical solutions in the present application or prior art clearer, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0046] The noise in life is often complex and diverse, mainly reflected in the following points: the diversity of the space environment of the noise, the diversity of the noise source types, the diversity of the noise source distribution, etc. For example, in a home environment, there are usually multiple noise sources: TV noise, human communication noise, environmental noise transmitted from outside the window, etc., and different noises may come from different directions. In the face of such a complex sound scene, it is usually very difficult to reproduce the noise in the laboratory.

[0047] The existing technologies mainly include the following three kinds:

[0048] 1) Use a single microphone to collect noise in an actual scene and store it, and then use a single loudspeaker to play back the collected noise in the laboratory. Using a single loudspeaker to play back, only a single directional noise can be played back, which cannot meet the diversity of actual scene noise. For example, actual scene noise often has multiple directional noise sources, both directional noise and diffuse field noise, so the noise accuracy of single loudspeaker playback is uncontrollable.

[0049] 2) Use a single microphone to collect noise in an actual scene and store it, and then use a 4 full-frequency loudspeaker + a subwoofer to play back the collected noise in the laboratory to reconstruct a diffuse field noise. This method can form a stable diffuse field noise at the sample to be tested, and can better control the sound field restoration accuracy in terms of sound pressure level and frequency spectrum, but it cannot restore directional noise sources, and the accuracy control is only for a certain position point in the center of the sound field. The accuracy of other positions cannot be guaranteed.

[0050] 3) Use a microphone array to collect noise in an actual scene and store it, and then use 8 loudspeakers to play back the recorded noise with a certain accuracy. The background noise restoration method using 8 loudspeakers can control the sound field accuracy of up to 8 position points in the center of the sound field. Although high accuracy can be obtained at 8 position points, the accuracy of other positions cannot be guaranteed.

[0051] Based on the above considerations, in order to improve the accuracy of the reconstructed sound field without being limited to the accuracy of certain position points in the center of the sound field, the inventive concept of the present application is to use a microphone array to collect the original sound source signal, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction. Since the parameters of the microphone array can be designed according to the accuracy requirement of sound field reconstruction, different sound field reconstruction accuracy requirements can be matched.

[0052] On this basis, the collected original sound source signal is subjected to circular harmonic decomposition and signal synthesis to obtain the playback signal of each loudspeaker in the reconstruction area, and the playback signal of each loudspeaker is used for sound field reconstruction in the reconstruction area. The processing method of circular harmonic decomposition and signal synthesis for the original sound source signal can ensure that a high-precision sound field is reconstructed in the center of the sound field, without being limited to the accuracy control of certain position points in the center of the sound field, thereby improving the accuracy of sound field reconstruction.

[0053] Based on the above inventive concept, the present application provides a sound field reconstruction method, device, system, electronic equipment and storage medium, which is applied to the sound field reconstruction scene in the field of audio processing, such as voice reconstruction in a conference scene, noise restoration in a voice interaction test or voice call test scene, audio reconstruction in a vehicle interior scene, etc., to improve the accuracy of sound field reconstruction.

[0054] The technical solutions of the present application will be described in detail below with reference to the drawings. Figure 1 is one of the flowcharts of the sound field reconstruction method provided by the present application. The execution subject of each step in this method can be a sound field reconstruction device, which can be realized by software and / or hardware. The device can be integrated in an electronic device, which can be a terminal device (such as a smart phone, a personal computer, a wearable device, etc.), a server (such as a local server or a cloud server, which can also be a server cluster, etc.), a processor, a chip, etc. As shown in the figure, the method can include the following steps: Figure 1

[0055] Step 110: Obtain the original sound source signal collected by the microphone array. The array structure of the microphone array is circular. The number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction.

[0056] Specifically, the original sound source signal is an audio signal generated by the original sound source that needs to be restored and reproduced. The original sound source can be one or more, and the corresponding original sound source signal can include one or more sound source signals. When the original sound source signal contains multiple sound source signals, the directions of the multiple sound source signals can be multi-directional, and high-precision reconstruction is required for the multiple sound source signals from multiple directions.

[0057] The collection of the original sound source signal can be realized by a microphone array. Here, the array structure of the microphone array is circular, i.e. the multiple microphones are arranged in a circular array. In order to accurately match the accuracy requirement of sound field reconstruction, the number of array elements and the array radius of the microphone array can be designed according to the accuracy requirement of sound field reconstruction before arranging the microphone array.

[0058] The accuracy requirement of sound field reconstruction can specifically include the upper limit frequency of the reconstruction area and the reconstruction radius. The reconstruction area refers to the area that needs to be reconstructed, which can be, for example, the free field environment of a laboratory. The reconstruction area can be an anechoic chamber. The upper limit frequency of the reconstruction area and the reconstruction radius can be pre-set or determined according to the reconstruction conditions of the reconstruction area, such as the size of the laboratory space and the number of speakers that can be placed to determine the reconstruction radius and the upper limit frequency.

[0059] On this basis, the number of array elements and the array radius of the microphone array can be designed according to the relationship between the number of array elements and the array radius of the microphone array and the upper limit frequency of the reconstruction area and the reconstruction radius, so as to ensure the accuracy of sound field reconstruction.

[0060] Step 120: Perform ring harmonic decomposition on the original sound source signal to obtain multiple ring harmonic components, and perform signal synthesis on the multiple ring harmonic components to obtain the playback signal of each speaker in the reconstruction area, which is used for sound field reconstruction in the reconstruction area.​

[0061] Specifically, after the original sound source signals are collected by the microphone array, the collected multi-channel original sound source signals need to be encoded and decoded. The signal encoding mainly decomposes the original sound source signals collected by the microphone array into the dimensions of the circular harmonic components, to obtain a plurality of circular harmonic components. The number of the circular harmonic components is positively correlated with the order of the microphone array.

[0062] Then, the plurality of circular harmonic components obtained by the circular harmonic decomposition are synthesized to re-synthesize new signals, i.e., signal decoding. The re-synthesized signals can be used as the playback signals of each loudspeaker in the reconstruction area. The number of loudspeakers for sound field reconstruction is greater than or equal to the number of microphone array elements, and the loudspeakers can also be arranged in a circular array.

[0063] In this embodiment, the collection of the original sound source signals and the sound field reconstruction can be independent of each other, i.e., the recording and the reconstruction do not affect each other, and only the corresponding microphone array and the arrangement of the loudspeakers need to be designed according to the accuracy requirement of the sound field reconstruction, so as to improve the accuracy of the sound field reconstruction.

[0064] The method provided in the embodiment of the present application can match different accuracy requirements of the sound field reconstruction, by designing the microphone array according to the accuracy requirement of the sound field reconstruction, and performing circular harmonic decomposition and signal synthesis on the original sound source signals collected by the microphone array to obtain the playback signals of each loudspeaker in the reconstruction area. In addition, the processing method of the circular harmonic decomposition and the signal synthesis on the original sound source signals can ensure that a high-precision sound field is reconstructed at the center of the sound field, and is not limited to the accuracy control of some position points in the center of the sound field, thereby improving the accuracy of the sound field reconstruction.

[0065] Based on the above embodiment, Figure 2 is a second flowchart of the sound field reconstruction method provided by the present application, as shown in Figure 2 The determination of the number of elements and the array radius of the microphone array includes:

[0066] Step 210, determining the accuracy requirement of the sound field reconstruction, the accuracy requirement including the reconstruction radius and the upper limit frequency of the reconstruction area;

[0067] Step 220, determining the number range of the number of elements of the microphone array based on the reconstruction radius and the upper limit frequency;

[0068] Step 230, determining the radius range of the array radius of the microphone array based on the number of elements of the microphone array and the upper limit frequency.

[0069] Specifically, the number of array elements and the array radius of the microphone array can be determined through steps 210-230. The accuracy requirement of the sound field reconstruction can specifically include an upper limit frequency of the reconstruction region and a reconstruction radius, which can be pre-set or determined according to the reconstruction condition of the reconstruction region, such as the reconstruction radius and the upper limit frequency can be determined according to the laboratory space size and the number of speakers that can be placed.

[0070] After obtaining the reconstruction radius and the upper limit frequency of the reconstruction region, the number of array elements of the microphone array can be determined based on the reconstruction radius and the upper limit frequency. The number of array elements of the microphone array should satisfy the following formula:

[0071]

[0072] In the formula, n represents the number of array elements of the microphone array, floor() is the floor function, c represents the speed of sound, f represents the upper limit frequency of the reconstruction region, and r d represents the reconstruction radius of the reconstruction region.

[0073] Then, the array radius of the microphone array is determined according to the number of array elements and the upper limit frequency of the microphone array. The array radius of the microphone array should satisfy the following formula:

[0074]

[0075] In the formula, r mic represents the array radius of the microphone array.

[0076] Through the above formula, the number range of the number of array elements of the microphone array and the radius range of the array radius of the microphone array can be obtained. It can be understood that the microphone array that satisfies the number range of the number of array elements and the radius range of the array radius can collect the original sound source signal to meet the accuracy requirement of the sound field reconstruction.

[0077] For example, it is calculated that the number range is n>7 and the radius range is r mic <5.1cm. The microphone array can be designed as follows: the number of array elements is 8 and the array radius is 5cm; or the microphone array can be designed as follows: the number of array elements is 9 and the array radius is 4.8cm, and so on. The microphone array that satisfies the range can meet the accuracy requirement of the sound field reconstruction.

[0078] The method provided by the embodiment of the application can determine the arrangement parameters of the microphone array through the relationship between the reconstruction radius and the upper limit frequency of the reconstruction region and the number of array elements and the array radius of the microphone array, and further ensures the reconstruction accuracy of the reconstructed sound field.

[0079] Based on any one of the above embodiments, Figure 3is a flowchart of step 110 in the sound field reconstruction method provided by the present application, as shown in Figure 3 Step 110 specifically includes:

[0080] Step 111, based on the accuracy requirement of sound field reconstruction, matching target parameters from multiple groups of microphone array parameters, the microphone array parameters including the number range and the radius range;

[0081] Step 112, obtaining the original sound source signal collected by the microphone array corresponding to the target parameters.

[0082] Specifically, considering that the recording microphone array device is relatively fixed and not easy to adjust in actual application, therefore, in order to meet different sound field reconstruction requirements with one set of array device, multiple groups of microphone arrays can be pre-set, and the multiple groups of microphone arrays correspond to multiple groups of microphone array parameters. Each group of microphone array parameters includes the number of array elements and the array radius.

[0083] On this basis, according to the accuracy requirement of sound field reconstruction, matching target parameters from multiple groups of microphone array parameters, the target parameters obtained thereby match the accuracy requirement of sound field reconstruction. Then, the original sound source signal collected by the microphone array corresponding to the target parameters can be obtained.

[0084] In some embodiments, multiple groups of concentric microphone arrays can be pre-designed for recording, that is, multiple groups of microphone arrays are designed into a concentric structure. The number of groups here can be any number, such as 2 groups, 3 groups, or 5 groups, etc., which is not specifically limited in the embodiments of the present application.

[0085] Figure 4 is a schematic diagram of multiple groups of microphone arrays provided by the present application, as shown in Figure 4 including 3 groups of microphone arrays, each group of microphone arrays includes multiple uniformly arranged microphones, the group of microphone arrays with the smallest array radius in the figure is arranged with 4 microphones, and the group of microphone arrays with the largest array radius is arranged with 16 microphones. Each group of microphone arrays corresponds to a group of microphone array parameters, and the microphone array parameters include the number range and the radius range. Multiple groups of microphone array data can be obtained at one time, each group of microphones can match one sound field reconstruction accuracy, and the microphone array with the corresponding array radius and the number of array elements can be selected for sound field reconstruction according to the actual reconstruction requirement.

[0086] The method provided by the embodiments of the present application can match different sound field reconstruction accuracy requirements and is more flexible and convenient.

[0087] Based on any of the above embodiments, step 112 specifically includes:

[0088] determine a plurality of groups of microphone arrays based on the target number range and the target radius range in the target parameter, the plurality of groups of microphone arrays being arranged concentrically;

[0089] obtain candidate sound source signals respectively collected by the plurality of groups of microphone arrays;

[0090] select an original sound source signal from the candidate sound source signals based on a signal-to-noise ratio and / or a signal-to-echo ratio of the candidate sound source signals.

[0091] Specifically, after the target number range and the target radius range in the target parameter are calculated based on the accuracy requirement of sound field reconstruction, the plurality of groups of microphone arrays can be determined according to the target number range and the target radius range, and the plurality of groups of microphone arrays are arranged concentrically.

[0092] In an embodiment, a reference array radius can be first determined according to the target radius range, and then the array radius of each group of microphone arrays can be set to differ by a preset threshold value, thereby obtaining the array radius of each group of microphone arrays. The preset threshold value can be an absolute value or a relative value. Subsequently, the number of array elements included in each group of microphone arrays can be determined according to the number of array elements that can be arranged in the array radius of each group of microphone arrays and the target number range.

[0093] For example, after the target radius range r is calculated to be less than 5.1 cm and the target number range n is calculated to be greater than 7, the array radius of each group of microphone arrays can be determined to be 5 cm, 4.5 cm, and 4 cm, and the corresponding number of array elements can be determined to be 10, 9, and 8, respectively. mic For example, after the target radius range r is calculated to be less than 5.1 cm and the target number range n is calculated to be greater than 7, the array radius of each group of microphone arrays can be determined to be 5 cm, 4.5 cm, and 4 cm, and the corresponding number of array elements can be determined to be 10, 9, and 8, respectively.

[0094] In actual application, the physical size of each microphone array element also needs to be considered, so that the corresponding number of array elements can be arranged within the corresponding array radius range.

[0095] After the plurality of groups of microphone arrays are arranged, candidate sound source signals respectively collected by the plurality of groups of microphone arrays can be obtained, wherein each group of microphone arrays corresponds to a group of candidate sound source signals.

[0096] Based on the signal-to-noise ratio and / or the signal-to-echo ratio of each group of candidate sound source signals, one group of candidate sound source signals can be selected as the original sound source signal. The signal-to-noise ratio is used to represent the power ratio of the normal sound signal intensity to the noise signal intensity when the audio playback device is playing, and the signal-to-echo ratio is used to represent the ratio of the normal sound signal intensity to the echo signal intensity when the audio playback device is playing.

[0097] It can be understood that the sound collection effect of the selected group of original sound source signals corresponding to the microphone array is optimal among the plurality of groups of microphone arrays, and therefore the group of microphone arrays can be selected as the microphone array corresponding to the target parameter.

[0098] The method provided by the embodiment of the application can further improve the accuracy of audio acquisition by selecting the original sound source signal based on the target parameter and the candidate sound source signals collected by the multiple microphone arrays.

[0099] Based on any of the above embodiments, the number and array radius of each loudspeaker are determined based on the number of elements and array radius of the microphone array.

[0100] Specifically, after obtaining the playing signal of each loudspeaker in the reconstruction area, the playing signal is the excitation signal of each loudspeaker, which is used for sound field reconstruction of the reconstruction area.

[0101] The sound field reconstruction of the reconstruction area can be performed in a free field environment (such as an anechoic chamber), in which each loudspeaker is arranged in a circular array, for example, M loudspeakers are placed uniformly at a radius r E The loudspeakers need to be selected from the same type of loudspeakers with good consistency, and the frequency response is as flat as possible. For those that do not meet the requirements of the frequency response curve, a filter can be designed for loudspeaker equalization.

[0102] The arrangement of the loudspeakers, i.e., the number and array radius of each loudspeaker, is determined based on the number of elements and array radius of the microphone array. For example, the number of loudspeakers can be greater than or equal to the number of microphones. The frequency upper limit of the reconstruction area can be determined according to the number of elements and array radius of the microphone array, and then the array radius of the loudspeaker can be determined according to the frequency upper limit.

[0103] Based on any of the above embodiments, the determination of the number and array radius of each loudspeaker includes:

[0104] Determining the maximum order of the microphone array based on the number of elements of the microphone array;

[0105] Determining the minimum number of each loudspeaker based on the maximum order of the microphone array;

[0106] Determining the array radius of each loudspeaker based on the maximum order and array radius of the microphone array.

[0107] Specifically, if a microphone array with n elements is selected for sound field reconstruction, the maximum order Q of the microphone array satisfies the following formula:

[0108]

[0109] In the formula, Q is the maximum order of the microphone array, n is the number of elements of the microphone array, and floor() is the floor function.

[0110] The maximum order of the microphone array is obtained, and the minimum number of each loudspeaker is determined, wherein the number of each loudspeaker satisfies the following formula:

[0111] M >= 2Q+1

[0112] In the formula, M represents the number of loudspeakers, and Q is the maximum order of the microphone array.

[0113] The array radius of each loudspeaker can be determined by the maximum order of the microphone array and the array radius. The array radius of each loudspeaker satisfies the following formula:

[0114]

[0115] In the formula, r E represents the array radius of each loudspeaker, and f h represents the upper limit of the frequency of sound field reconstruction.

[0116] Meanwhile, the upper limit f h of the frequency of sound field reconstruction satisfies the following formula:

[0117]

[0118] In the formula, r mic represents the array radius of the microphone array.

[0119] The method provided by the embodiment of the application can design a reasonable microphone array and loudspeaker arrangement according to the expected sound field radius or upper limit frequency of reconstruction through the above method.

[0120] Based on any of the above embodiments, a plurality of ring harmonic components are signal synthesized to obtain the playing signal of each loudspeaker in the reconstruction area, including:

[0121] Based on the number and placement angle of each loudspeaker, a plurality of ring harmonic components are signal synthesized to obtain the playing signal of each loudspeaker in the reconstruction area.

[0122] Specifically, the plurality of ring harmonic components are obtained by signal encoding a plurality of original sound source signals, and can be realized through the following formula:

[0123]

[0124] In the formula, S q is the qth ring harmonic component, S0(i) is the signal amplitude of the ith microphone element, and θ i is the angle of the ith microphone element. The Q-order ring harmonic decomposition will generate 2*q+1 ring harmonic components.

[0125] On this basis, based on the number and the angle of each loudspeaker, a plurality of ring harmonic components are signal synthesized to obtain the playing signal of each loudspeaker in the reconstruction area, and the signal synthesis process is signal decoding, which can be realized by the following formula:

[0126]

[0127] In the formula, M is the number of loudspeakers, is the angle of the i-th loudspeaker, is the playing signal of the i-th loudspeaker.

[0128] Based on any of the above embodiments, taking noise restoration as an example, a sound field reconstruction method is provided, comprising:

[0129] S1, on-site noise collection. The noise is collected by a specially designed multi-ring microphone array, the array structure of the multi-ring microphone array is circular, each ring of microphones is uniformly arranged, and the number of array elements and the array radius of each ring of microphone array are determined based on the accuracy requirement of sound field reconstruction.

[0130] S2, noise signal processing. The collected multi-channel noise signal is encoded and decoded. Signal encoding mainly decomposes the spatial signal collected by the microphone array into ring harmonic components in each dimension. Signal decoding is to recombine the ring harmonic components generated in the encoding stage into a new signal as the excitation signal of the loudspeaker.

[0131] S3, laboratory playback. M loudspeakers are placed uniformly at a radius r E in a free field environment (such as an anechoic chamber) for noise playback.

[0132] The method provided by the embodiment of the application is based on field restoration technology, can realize effective restoration of the noise sound field, and the restored sound field is no longer limited to some single point position, but a certain radius of space, which is closer to the real scene; the sound field restoration scheme based on ring harmonic decomposition and reconstruction is more flexible and convenient to apply, the recording and reconstruction do not affect each other, and different precision schemes can be selected according to actual needs, which can help users to develop a reasonable scheme according to actual needs at the beginning of application; the system is more reliable, and the solution result of the scheme is stable and will not fail.

[0133] The sound field reconstruction device provided by the application is described below, and the sound field reconstruction device described below can be correspondingly referred to the sound field reconstruction method described above.

[0134] Based on any of the above embodiments, Figure 5 is a structural schematic diagram of the sound field reconstruction device provided by the application, like Figure 5As shown, the embodiment of the present application provides a sound field reconstruction device, which comprises a signal acquisition unit 510 and a signal processing unit 520, wherein:

[0135] The signal acquisition unit 510 is configured to acquire an original sound source signal collected by a microphone array, wherein an array structure of the microphone array is circular, and a number of array elements and an array radius of the microphone array are determined based on a precision requirement of sound field reconstruction.

[0136] The signal processing unit 520 is configured to perform ring harmonic decomposition on the original sound source signal to obtain a plurality of ring harmonic components, and perform signal synthesis on the plurality of ring harmonic components to obtain a playing signal of each loudspeaker in a reconstruction area, wherein the playing signal of each loudspeaker is used for sound field reconstruction in the reconstruction area.

[0137] The sound field reconstruction device provided by the embodiment of the present application can match different precision requirements of sound field reconstruction by designing the microphone array according to the precision requirement of sound field reconstruction, and performing ring harmonic decomposition and signal synthesis on the original sound source signal collected by the microphone array to obtain the playing signal of each loudspeaker in the reconstruction area. In addition, the processing method of performing ring harmonic decomposition and signal synthesis on the original sound source signal can ensure that a high-precision sound field is reconstructed at the center of the sound field, and is not limited to precision control at some position points of the center of the sound field, thereby improving the precision of sound field reconstruction.

[0138] Based on any one of the above embodiments, the sound field reconstruction device further comprises a microphone design unit configured to:

[0139] determine a precision requirement of sound field reconstruction, wherein the precision requirement comprises a reconstruction radius of a reconstruction area and an upper limit frequency;

[0140] determine a number range in which a number of array elements of the microphone array is located based on the reconstruction radius and the upper limit frequency;

[0141] determine a radius range in which an array radius of the microphone array is located based on the number of array elements of the microphone array and the upper limit frequency.

[0142] Based on any one of the above embodiments, the signal acquisition unit 510 is further configured to:

[0143] match target parameters from a plurality of microphone array parameters based on the precision requirement of sound field reconstruction, wherein the microphone array parameters comprise the number range and the radius range;

[0144] acquire an original sound source signal collected by a microphone array corresponding to the target parameters.

[0145] Based on any one of the above embodiments, the signal acquisition unit 510 is further configured to:

[0146] determine a plurality of groups of microphone arrays based on the target number range and the target radius range in the target parameters, the plurality of groups of microphone arrays being arranged concentrically;

[0147] acquire candidate sound source signals collected by the plurality of groups of microphone arrays respectively;

[0148] select the original sound source signal from the candidate sound source signals based on signal-to-noise ratios and / or signal-to-interference ratios of the candidate sound source signals.

[0149] Based on any of the above embodiments, the plurality of loudspeakers are arranged in a circular array, and the number and array radius of the plurality of loudspeakers are determined based on the number of array elements and the array radius of the microphone array.

[0150] Based on any of the above embodiments, the sound field reconstruction device further comprises a loudspeaker design unit configured to:

[0151] determine the maximum order of the microphone array based on the number of array elements of the microphone array;

[0152] determine the minimum number of the plurality of loudspeakers based on the maximum order of the microphone array;

[0153] determine the array radius of the plurality of loudspeakers based on the maximum order and the array radius of the microphone array.

[0154] Based on any of the above embodiments, the signal processing unit 520 is further configured to:

[0155] perform signal synthesis on the plurality of circular harmonic components based on the number and placement angle of the plurality of loudspeakers to obtain a playback signal of each loudspeaker in the reconstruction area.

[0156] Based on any of the above embodiments, Figure 6 is a structural schematic diagram of a sound field reconstruction system provided by the present application, as Figure 6 shown, the sound field reconstruction system comprises a processor 610 and a plurality of loudspeakers 620, the processor being connected to each loudspeaker, and in the figure, the sound field reconstruction system comprises four loudspeakers as an example, and in actual application, the number of loudspeakers can be flexibly selected according to design needs.

[0157] The processor is configured to acquire an original sound source signal collected by a microphone array, perform circular harmonic decomposition on the original sound source signal to obtain a plurality of circular harmonic components, and perform signal synthesis on the plurality of circular harmonic components to obtain a playback signal of each loudspeaker in a reconstruction area, the array structure of the microphone array being circular, and the number of array elements and the array radius of the microphone array being determined based on accuracy requirements of sound field reconstruction.

[0158] The plurality of loudspeakers are configured to play the playback signal.

[0159] The sound field reconstruction system provided in this invention allows recording and reconstruction to be independent and unaffected by each other. The processing method of ring harmonic decomposition and signal synthesis of the original sound source signal ensures the reconstruction of a high-precision sound field at the center of the sound field, rather than being limited to the precision control of certain points at the center, thereby improving the accuracy of sound field reconstruction.

[0160] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute a sound field reconstruction method, which includes:

[0161] The original sound source signal is acquired by a microphone array, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirements of sound field reconstruction.

[0162] The original sound source signal is decomposed into ring harmonics to obtain multiple ring harmonic components. The multiple ring harmonic components are then synthesized to obtain the playback signals of each speaker in the reconstruction area. The playback signals of each speaker are used for sound field reconstruction in the reconstruction area.

[0163] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0164] In another aspect, the present application also provides a computer program product, which comprises a computer program, the computer program being stored in a non-transitory computer readable storage medium, and the computer program being executable by a processor to enable a computer to perform the sound field reconstruction method provided by the above-mentioned methods, and the method comprises:

[0165] obtaining original sound source signals collected by a microphone array, wherein an array structure of the microphone array is circular, and a number of array elements and an array radius of the microphone array are determined based on an accuracy requirement of sound field reconstruction;

[0166] performing ring harmonic decomposition on the original sound source signals to obtain a plurality of ring harmonic components, and performing signal synthesis on the plurality of ring harmonic components to obtain a playing signal of each loudspeaker in a reconstruction area, wherein the playing signal of each loudspeaker is used for sound field reconstruction in the reconstruction area.

[0167] In yet another aspect, the present application also provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executable by a processor to implement a sound field reconstruction method provided by the above-mentioned methods, and the method comprises:

[0168] obtaining original sound source signals collected by a microphone array, wherein an array structure of the microphone array is circular, and a number of array elements and an array radius of the microphone array are determined based on an accuracy requirement of sound field reconstruction;

[0169] performing ring harmonic decomposition on the original sound source signals to obtain a plurality of ring harmonic components, and performing signal synthesis on the plurality of ring harmonic components to obtain a playing signal of each loudspeaker in a reconstruction area, wherein the playing signal of each loudspeaker is used for sound field reconstruction in the reconstruction area.

[0170] The apparatus embodiments described above are merely illustrative, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., they can be located in one place, or distributed on a plurality of network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment scheme. Those skilled in the art can understand and implement it without creative labor.

[0171] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0172] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A sound field reconstruction method, characterized by, The method comprises the following steps: obtaining original sound source signals collected by a microphone array, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction; performing ring harmonic decomposition on the original sound source signals to obtain a plurality of ring harmonic components, and performing signal synthesis on the plurality of ring harmonic components to obtain a playing signal of each loudspeaker in a reconstruction area, wherein the playing signal of each loudspeaker is used for sound field reconstruction in the reconstruction area; the loudspeakers are arranged in a circular array, and the number and array radius of the loudspeakers are determined based on the number of array elements and the array radius of the microphone array; the determination of the number of array elements and the array radius of the microphone array comprises: determining the accuracy requirement of sound field reconstruction, wherein the accuracy requirement comprises a reconstruction radius and an upper limit frequency of the reconstruction area; based on the reconstruction radius and the upper limit frequency, determining a number range in which the number of array elements of the microphone array is located; based on the number of array elements of the microphone array and the upper limit frequency, determining a radius range in which the array radius of the microphone array is located.

2. The sound field reconstruction method of claim 1, wherein, The method comprises the following steps: based on the accuracy requirement of sound field reconstruction, matching target parameters from a plurality of microphone array parameters, wherein the microphone array parameters comprise the number range and the radius range; obtaining original sound source signals collected by a microphone array corresponding to the target parameters.

3. The sound field reconstruction method of claim 2, wherein, The method comprises the following steps: based on the target number range and the target radius range in the target parameters, determining a plurality of microphone arrays, wherein the plurality of microphone arrays are arranged concentrically; obtaining candidate sound source signals collected by the plurality of microphone arrays respectively; based on the signal-to-noise ratio and / or signal-to-interference ratio of the candidate sound source signals, selecting the original sound source signals from the candidate sound source signals.

4. The sound field reconstruction method of claim 1, wherein, The method comprises the following steps: based on the number of array elements of the microphone array, determining the maximum order of the microphone array; based on the maximum order of the microphone array, determining the minimum number of the loudspeakers; based on the maximum order and the array radius of the microphone array, determining the array radius of the loudspeakers.

5. The sound field reconstruction method of any one of claims 1 to 4, wherein, The method comprises the following steps: based on the number and placement angle of the loudspeakers, performing signal synthesis on the plurality of ring harmonic components to obtain the playing signal of each loudspeaker in the reconstruction area.

6. An acoustic field reconstruction apparatus, characterized by The method comprises the following steps: a signal acquisition unit is configured to obtain original sound source signals collected by a microphone array, wherein the array structure of the microphone array is circular, and the number of array elements and the array radius of the microphone array are determined based on the accuracy requirement of sound field reconstruction. A signal processing unit is configured to perform a circular harmonic decomposition on the original sound source signal to obtain a plurality of circular harmonic components, and to perform a signal synthesis on the plurality of circular harmonic components to obtain a playback signal for each loudspeaker in a reconstruction area, the playback signal being used for sound field reconstruction in the reconstruction area; the loudspeakers are arranged in a circular array, and a number and an array radius of the loudspeakers are determined based on a number and an array radius of the microphone array. The number and the array radius of the microphone array are determined by: determining an accuracy requirement for the sound field reconstruction, the accuracy requirement including a reconstruction radius and an upper limit frequency of the reconstruction area; determining a number range of the number of the microphone array based on the reconstruction radius and the upper limit frequency; determining a radius range of the array radius of the microphone array based on the number of the microphone array and the upper limit frequency.

7. A sound field reconstruction system, characterized by The system comprises a processor and a plurality of loudspeakers, the processor being connected to each loudspeaker; The processor is configured to obtain an original sound source signal collected by a microphone array, perform a circular harmonic decomposition on the original sound source signal to obtain a plurality of circular harmonic components, and perform a signal synthesis on the plurality of circular harmonic components to obtain a playback signal for each loudspeaker in a reconstruction area, an array structure of the microphone array being circular, and a number and an array radius of the microphone array being determined based on an accuracy requirement for sound field reconstruction; The plurality of loudspeakers are configured to play the playback signal; The loudspeakers are arranged in a circular array, and a number and an array radius of the loudspeakers are determined based on a number and an array radius of the microphone array. The number and the array radius of the microphone array are determined by: determining an accuracy requirement for the sound field reconstruction, the accuracy requirement including a reconstruction radius and an upper limit frequency of the reconstruction area; determining a number range of the number of the microphone array based on the reconstruction radius and the upper limit frequency; determining a radius range of the array radius of the microphone array based on the number of the microphone array and the upper limit frequency.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the sound field reconstruction method according to any one of claims 1 to 5 when executing the program. 9.A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program implements the sound field reconstruction method according to any one of claims 1 to 5 when executed by the processor.

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