Multi-channel microphone calibration system and method

Abstract

The invention provides a multichannel microphone calibration system and method. The system comprises a multi-channel coupler, electronic equipment, an acoustic calibrator and a signal acquisition device, the multi-channel coupler comprises a multi-channel coupling cavity and a sound source excitation interface arranged on the multi-channel coupling cavity, the sound source excitation interface is used for being connected with the acoustic calibrator, and the multi-channel coupling cavity is further provided with a plurality of through holes for embedding microphones; wherein the acoustic calibrator is used for inputting an excitation signal to the multi-channel coupler under the control of electronic equipment; the multi-channel coupler is used for transmitting excitation signals to the microphones embedded in the plurality of through holes; the signal acquisition device is used for acquiring sound response signals of the microphones and amplifying the sound response signals; the electronic equipment is used for acquiring the sound response signals amplified by the microphones; and calibrating the sensitivity of the corresponding microphone according to the amplified sound response signal and excitation signal. The system is used for achieving the effects of improving the calibration efficiency and reducing errors.

Description

Technical Field

[0001] This application relates to the field of audio testing technology, and in particular to a multi-channel microphone calibration system and method. Background Technology

[0002] In the field of audio testing, microphone sensitivity calibration is a crucial step in ensuring the accuracy of acoustic measurements. Microphone sensitivity calibration is widely used in laboratory acoustic research, consumer electronics and automotive audio systems, industrial noise monitoring equipment, and other industrial applications. The calibration process verifies the microphone's sensitivity using standardized sound pressure levels to ensure the accuracy of its output signal. In practical applications, testing microphone arrays typically involves calibrating multiple microphones.

[0003] In related technologies, multiple microphones are inserted one by one into the cavity of an acoustic calibrator, and the acoustic calibrator is activated to generate an excitation signal. For each microphone inserted into the cavity of the acoustic calibrator, the acoustic response signal of the microphone is amplified by a preamplifier electrically connected to the microphone, and the amplified acoustic response signal is transmitted to a data processing device. The data processing device determines the sensitivity of the microphone currently inserted into the coupling cavity based on the amplified acoustic response signal and the excitation signal.

[0004] However, the above methods suffer from low efficiency and large errors. Summary of the Invention

[0005] This application provides a multi-channel microphone calibration system and method to improve calibration efficiency and reduce errors.

[0006] In a first aspect, this application provides a multi-channel microphone calibration system, comprising: a multi-channel coupler, an electronic device, and an acoustic calibrator and a signal acquisition device communicatively connected to the electronic device. The multi-channel coupler includes a multi-channel coupling cavity and a sound source excitation interface disposed on the multi-channel coupling cavity. The sound source excitation interface is used to connect to the acoustic calibrator. The multi-channel coupling cavity is also provided with multiple through holes for embedding microphones; wherein:

[0007] An acoustic calibrator is used to input a set excitation signal into the acoustic source excitation interface of a multi-channel coupler under the control of electronic equipment.

[0008] A multi-channel coupler is used to transmit excitation signals to a microphone embedded in multiple through-holes;

[0009] The signal acquisition device is used to acquire the acoustic response signals of each microphone in response to the excitation signal and amplify the acoustic response signals;

[0010] An electronic device used to acquire the amplified acoustic response signal corresponding to each microphone; and to calibrate the sensitivity of the corresponding microphone based on the amplified acoustic response signal and the excitation signal.

[0011] In one possible implementation, the first resonant frequency of the multi-channel coupling cavity is greater than a preset multiple of the frequency corresponding to the excitation signal, wherein the preset multiple is greater than or equal to 2.

[0012] In one possible implementation, the multi-channel coupling cavity is assembled from modular prefabricated blocks to accommodate different numbers of microphones.

[0013] In one possible implementation, the multi-channel coupling cavity is a cube, cuboid, or sphere; and / or, the through holes are equidistantly distributed.

[0014] In one possible implementation, the multi-channel coupling cavity is provided with an acoustic conduit connected to a through hole, the acoustic conduit being used to directionally guide the excitation signal to a microphone embedded in the through hole.

[0015] In one possible implementation, the multi-channel coupling cavity is made of a flexible material, and the opening size of the through-hole varies under external pressure to accommodate microphones of different sizes.

[0016] In one possible implementation, the signal acquisition device includes a multi-channel preamplifier electrically connected to each microphone.

[0017] In one possible implementation, the multi-channel microphone calibration system further includes an embedded sensor array for real-time monitoring of the sound pressure distribution within the multi-channel coupling cavity and for transmitting the monitoring results corresponding to the sound pressure distribution to an electronic device.

[0018] Correspondingly, the electronic equipment is also used to dynamically adjust the excitation parameters of the acoustic calibrator based on the monitoring results.

[0019] Secondly, this application provides a multi-channel microphone calibration method, applied to an electronic device in the multi-channel microphone calibration system of the first aspect. The multi-channel microphone calibration method includes:

[0020] Control the input of the set excitation signal to the sound source excitation interface of the multi-channel coupler;

[0021] The amplified acoustic response signals of each microphone to the excitation signal are acquired from the signal acquisition device;

[0022] The sensitivity of the corresponding microphone is calibrated based on the amplified acoustic response signal and excitation signal.

[0023] Thirdly, this application provides an electronic device, including: a memory and a processor;

[0024] The memory stores instructions that the computer executes;

[0025] The processor executes computer execution instructions stored in memory, causing the processor to perform the multi-channel microphone calibration method described in the second aspect above.

[0026] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the multi-channel microphone calibration method of the second aspect above.

[0027] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the multi-channel microphone calibration method as described in the second aspect above.

[0028] This application provides a multi-channel microphone calibration system and method, comprising: a multi-channel coupler, electronic equipment, and an acoustic calibrator and a signal acquisition device communicatively connected to the electronic equipment. The multi-channel coupler includes a multi-channel coupling cavity and a sound source excitation interface disposed on the multi-channel coupling cavity. The sound source excitation interface is used to connect to the acoustic calibrator. The multi-channel coupling cavity is also provided with multiple through holes for embedding microphones. The acoustic calibrator, under the control of the electronic equipment, inputs a set excitation signal to the sound source excitation interface of the multi-channel coupler. The multi-channel coupler transmits the excitation signal to the microphones embedded in the multiple through holes. The signal acquisition device acquires the acoustic response signal of each microphone in response to the excitation signal and amplifies the acoustic response signal. The electronic equipment acquires the amplified acoustic response signal corresponding to each microphone. Based on the amplified acoustic response signal and the excitation signal, the sensitivity of the corresponding microphone is calibrated. This multi-channel microphone calibration system introduces a multi-channel coupler, which simultaneously transmits the excitation signal to multiple microphones, enabling parallel calibration of multiple microphones. The calibration time decreases linearly with the number of microphones, greatly improving calibration efficiency. In addition, multiple microphones to be calibrated are located in the same multi-channel coupling cavity to ensure the consistency of the calibration environment, eliminate calibration errors of each microphone caused by environmental differences, and improve the consistency of calibration data. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 A flowchart illustrating a multi-channel microphone calibration scheme in related technologies;

[0031] Figure 2 This is a schematic diagram of the structure of the multi-channel microphone calibration system provided in the embodiments of this application;

[0032] Figure 3 This is a schematic diagram of the structure of the multi-channel cubic coupling cavity provided in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the structure of the multi-channel spherical coupling cavity provided in the embodiments of this application;

[0034] Figure 5 This is a schematic diagram of the structure of the multi-channel cuboid coupling cavity provided in the embodiments of this application;

[0035] Figure 6 A schematic flowchart illustrating the multi-channel microphone calibration method provided in this application embodiment;

[0036] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0037] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0038] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0039] The terms “first,” “second,” etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, products, or apparatus.

[0040] Figure 1 This is a flowchart illustrating a multi-channel microphone calibration scheme in related technologies. (Example:) Figure 1As shown, the acoustic calibrator acts as a standard sound source, generating an excitation signal (i.e., a sound pressure reference) upon activation. Microphones are inserted sequentially into the cavity of the acoustic calibrator. Each inserted microphone generates an acoustic response signal under the excitation signal. This signal is amplified by a preamplifier electrically connected to the microphone and transmitted to a data processing device (such as a data analyzer). The data processing device then calculates the microphone's sensitivity by comparing the amplitude of the amplified acoustic response signal with the standard sound pressure level corresponding to the excitation signal. In actual calibration, each microphone is typically calibrated multiple times, and the average sensitivity is taken to reduce random errors. This process is repeated for the other N-1 microphones to be calibrated, ultimately completing the sensitivity calibration of the microphone array. However, this method requires calibrating each microphone individually, and the calibration time increases linearly with the number of microphones, resulting in low calibration efficiency. Furthermore, the microphones may be in different acoustic environments (e.g., temperature and humidity fluctuations) during each calibration, leading to large dispersion in the calibration results. Additionally, frequent microphone repositioning increases manual operation costs and the probability of errors.

[0041] To address the aforementioned technical issues, the multi-channel microphone calibration system provided in this application incorporates a multi-channel coupler. This coupler simultaneously transmits the sound pressure generated by the acoustic calibrator to multiple microphones, enabling simultaneous calibration of multiple microphones. This solves the problems of low efficiency and inconsistent environments caused by traditional individual calibration.

[0042] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0043] Figure 2 This is a schematic diagram of the structure of a multi-channel microphone calibration system provided in an embodiment of this application. Figure 2 As shown, the multi-channel microphone calibration system includes: a multi-channel coupler 21, an electronic device 22, an acoustic alignment device 23 and a signal acquisition device 24 that are communicatively connected to the electronic device 22. The multi-channel coupler 21 includes a multi-channel coupling cavity 211 and a sound source excitation interface 212 disposed on the multi-channel coupling cavity 211. The sound source excitation interface 212 is used to connect to the acoustic alignment device 23. The multi-channel coupling cavity 211 is also provided with multiple through holes 213 for embedding microphones; wherein:

[0044] Acoustic calibrator 23 is used to input a set excitation signal to the sound source excitation interface 212 of the multi-channel coupler 21 under the control of electronic device 22.

[0045] Multichannel coupler 21 is used to transmit excitation signals to microphones embedded in multiple through holes;

[0046] The signal acquisition device 24 is used to acquire the acoustic response signals of each microphone in response to the excitation signal and amplify the acoustic response signals;

[0047] Electronic device 22 is used to acquire the amplified acoustic response signal corresponding to each microphone; and to calibrate the sensitivity of the corresponding microphone based on the amplified acoustic response signal and the excitation signal.

[0048] It should be understood that the multi-channel coupling cavity 211 is an acoustically optimized cavity used to provide a uniform and stable sound field environment to the microphone to be calibrated. When the excitation signal (i.e., standard sound pressure) generated by the acoustic calibrator 23 is emitted within the multi-channel coupling cavity 211, the sound pressure is uniformly distributed at all points within the multi-channel coupling cavity 211. The sound source excitation interface 212 is a standard interface, such as a screw thread or sleeve, provided on the multi-channel coupling cavity 211. This sound source excitation interface 212 is used for physical connection and acoustic sealing to fix the acoustic calibrator 23, enabling the excitation signal to be efficiently coupled into the multi-channel coupling cavity 211. Through holes are used to embed and fix the microphone, ensuring that the microphone diaphragm is exposed to the uniform sound field of the multi-channel coupling cavity 211.

[0049] It should be noted that, Figure 2 This is merely an illustrative diagram and does not constitute a specific limitation on the multi-channel microphone calibration system of this application. In actual testing scenarios, if the number of microphones to be calibrated is less than the number of through holes, sealing plugs can be used to seal the excess through holes to ensure the airtightness of the multi-channel coupling cavity 211. Furthermore, this embodiment does not limit the shape of the multi-channel coupling cavity 211, nor does it impose specific limitations on the material of the multi-channel coupling cavity 211; it can be metal, plastic, etc., as long as it meets the rigidity requirements for testing. The first-order resonant frequency of the multi-channel coupling cavity is much higher than the frequency corresponding to the excitation signal.

[0050] The acoustic calibrator 23 serves as a standard sound source, typically a high-precision acoustic signal generator, used to generate an acoustic signal with a known frequency and a known precise sound pressure level (e.g., 1 kHz, 94 dB). The output of the acoustic calibrator 23 is controlled by electronic equipment 22, which controls, for example, the start and stop of the acoustic calibrator 23 and the parameters of the excitation signal.

[0051] The signal acquisition device 24 simultaneously acquires the weak electrical signals generated by multiple microphones after receiving an excitation signal, and amplifies the weak electrical signals through a built-in preamplifier. Optionally, the amplified analog electrical signals can be further converted into digital signals for reading by the electronic device 22.

[0052] Electronic device 22 receives amplified acoustic response signals from each channel of signal acquisition device 24 and performs analog-to-digital conversion to obtain amplified digital signals; or it receives amplified digital signals from each channel of signal acquisition device 24. Then, based on a preset sensitivity algorithm, it calculates the sensitivity of each microphone.

[0053] For example, before calibration begins, the acoustic calibrator 23 is installed onto the acoustic source excitation interface 212 of the multi-channel coupler 21, forming an acoustic seal. Multiple microphones to be calibrated are respectively embedded in the through-holes of the multi-channel coupling cavity 211, ensuring that the microphone probes are located within the cavity. The acoustic calibrator 23 is connected to the electronic device 22 via cables (such as Ethernet, USB, etc.) and receives control commands from the electronic device 22. The output cables of the multiple microphones are connected to the respective input channels of the signal acquisition device 24. The signal acquisition device 24 is connected to the electronic device 22 via a high-speed data bus (such as USB, Thunderbolt, or PCIe) to transmit data.

[0054] During calibration, for example, when the user clicks "Start Calibration" on the software interface of the electronic device, the software sends a command to the acoustic calibrator 23, which is then activated. The acoustic calibrator 23 emits a set, stable standard acoustic excitation signal into the multi-channel coupling cavity 211 of the multi-channel coupler 21. For example, the sound pressure level is 94 dB, corresponding to a sound pressure value of 1 Pa, and the frequency is 250 Hz. The excitation signal forms a uniform sound field within the multi-channel coupling cavity 211. Due to the uniformity of the sound field, all microphones embedded in each through-hole are simultaneously exposed to the same sound pressure. Each microphone generates a corresponding weak electrical signal (i.e., an acoustic response signal) based on its own characteristics. The acoustic response signals generated by all microphones are synchronously acquired by the signal acquisition device 24, which then transmits the acoustic response signals to the electronic device 22. Assuming the amplitude (i.e., voltage value) of the acoustic response signal of microphone a is 12.5 mV, then the sensitivity of microphone a = 0.0125 V / 1 Pa = 0.0125 V / Pa.

[0055] In this embodiment, a multi-channel coupler is introduced into the multi-channel microphone calibration system. The excitation signal is simultaneously transmitted to multiple microphones via the multi-channel coupler, enabling parallel calibration of multiple microphones. The calibration time decreases linearly with the number of microphones, significantly improving calibration efficiency. Furthermore, the multiple microphones to be calibrated are housed in the same multi-channel coupling cavity, ensuring a consistent calibration environment and eliminating calibration errors caused by environmental differences, thus improving the consistency of calibration data. In addition, this system minimizes manual operations such as repeatedly plugging and unplugging microphones, avoiding human error and improving the objectivity and repeatability of calibration results.

[0056] In some embodiments, the first resonant frequency of the multi-channel coupling cavity is greater than a preset multiple of the frequency corresponding to the excitation signal, wherein the preset multiple is greater than or equal to 2.

[0057] The first-order resonant frequency, also known as the fundamental frequency, is the lowest frequency at which a multi-channel coupled cavity most easily and strongly resonates. It should be understood that when the frequency of an external sound source (i.e., the excitation signal) is close to or equal to the first-order resonant frequency of the multi-channel coupled cavity, the sound waves within the cavity will superimpose and amplify, forming standing waves. This results in extremely uneven sound pressure distribution within the cavity, with some points exhibiting extremely high sound pressure (antinodes) and others exhibiting extremely low sound pressure (nodes). Consequently, the sound pressure perceived by microphones at different locations will show significant differences, leading to severely inaccurate calculated sensitivity and non-repeatable calibration results.

[0058] The first-order resonant frequency is related to the size of the multi-channel coupled cavity; the smaller the size, the higher the first-order resonant frequency. When designing a multi-channel coupled cavity, the cavity size can be calculated and optimized using simulation software based on acoustic theory. In an acoustic system, the response is flat and uniform only in frequency bands far below its first-order resonant frequency. This application raises the first-order resonant frequency to twice or more of the operating frequency band, indicating that the entire operating frequency band (e.g., from 250Hz to 10kHz) lies within this flat and uniform response region. Within the operating frequency band, the cavity does not resonate, and the sound waves propagate with uniform phase and amplitude, avoiding the formation of standing waves, thus distributing a highly uniform sound field within the cavity.

[0059] Table 1 below shows the sound pressure levels at the locations of the five microphones in the multi-channel coupling cavity when the first-order resonant frequency is 3736Hz, the excitation signal frequency is 250Hz, and the multi-channel coupling cavity is a cube.

[0060] Table 1

[0061]

[0062] As can be seen from Table 1, the sound pressure level felt by microphones at different locations is the same.

[0063] In this embodiment, the first-order resonant frequency of the multi-channel coupled cavity is designed to be greater than twice the frequency corresponding to the excitation signal, thereby suppressing the resonance of the multi-channel coupled cavity, ensuring the uniformity of the sound field within the working frequency band, and thus ensuring the accuracy of the multi-channel microphone calibration.

[0064] Given that the number of through-holes for embedding microphones on a single-piece multi-channel coupling cavity is fixed, when the number of microphones needs to be changed, such as for different sizes of microphone arrays under test, either the entire multi-channel coupling cavity must be redesigned and manufactured, resulting in long development cycles, high costs, and low flexibility; or the microphones must be calibrated in batches, affecting calibration efficiency. Therefore, in some embodiments, the multi-channel coupling cavity is assembled from modular prefabricated blocks to accommodate different numbers of microphones.

[0065] For example, each prefabricated block has N (e.g., 4) independent through holes pre-machined inside. Furthermore, high-precision locating pins and corresponding locating pin holes are provided on the splicing surface of each prefabricated block. During assembly, the locating pins are first inserted into the pin holes, and then standard screws are passed through the threaded holes on the prefabricated blocks and tightened with the threaded holes of adjacent modules, thereby rigidly fixing all prefabricated blocks together. Sealing ring grooves (e.g., grooves with embedded elastic sealing rings) are also machined on the splicing surface of each prefabricated block. When the modules are tightened, the sealing rings are compressed, resulting in a strict acoustic seal between the inside of the multi-channel coupling cavity and the external environment, preventing sound leakage and crosstalk.

[0066] For example, the current multi-channel coupling cavity has 8 channels (8 through holes for embedding microphones). When the calibration requirement is upgraded to 16 channels, an 8-channel prefabricated block can be added on the basis of the current 8-channel coupling cavity.

[0067] In this embodiment, the multi-channel coupling cavity is designed as a modular unit, allowing for the combination of multiple modules to adapt to different microphone calibration requirements. This improves the flexibility and versatility of the multi-channel coupler, meets diverse testing needs, and reduces manufacturing costs and time. Furthermore, if a prefabricated block is damaged due to impact or other reasons, only the damaged single prefabricated block needs to be replaced, reducing maintenance costs.

[0068] In some embodiments, the multi-channel coupling cavity is a cube, cuboid, or sphere; and / or, the through holes are equidistantly distributed.

[0069] The equidistant distribution of vias can be considered as the geometric distance between the center points of adjacent vias being equal, such as a grid-like equidistant distribution forming a regular matrix; or a circumferential equidistant distribution, such as on the surface of a sphere, where vias are evenly distributed on concentric circles, and the arc length distance between adjacent vias on the same circle is equal. The equidistant distribution of vias ensures that the geometric position of the receiver end of each calibrated microphone within the cavity is regular and symmetrical, minimizing sound pressure level and phase measurement errors caused by positional differences.

[0070] For multi-channel coupled cavities of cubes or cuboids, the sound source excitation interface is typically located on one of the planes, and multiple through holes are usually regularly distributed on one or more planes opposite or adjacent to the sound source excitation interface. Optionally, the through holes on each plane are equidistantly distributed.

[0071] For a multi-channel coupled cavity shaped like a sphere, the sound source excitation interface is typically located at one pole of the sphere, so that the excitation signal is emitted from the centrally symmetrical point. Theoretically, this can most uniformly excite the sound field throughout the entire spherical cavity. Multiple through-holes can be distributed on the surface of the sphere. Optionally, the multiple through-holes on the sphere can be evenly distributed.

[0072] Figure 3 This is a schematic diagram of the structure of the multi-channel cubic coupling cavity provided in the embodiments of this application, as shown below. Figure 3 As shown, Figure 3 Images (a) through (d) showcase the multi-channel cubic coupling cavity from different angles. Figure 3 Image (a) is a 3D view of the whole. Figure 3 (b) is the front view. Figure 3 (c) is a side view. Figure 3 The top view is shown in Figure d. As shown, the sound source excitation interface is located on the top plane, and each of the other planes has a through hole.

[0073] Figure 4 This is a schematic diagram of the structure of the multi-channel spherical coupling cavity provided in the embodiments of this application, as shown below. Figure 4 As shown, Figure 4 Images (a) through (d) showcase the multi-channel spherical coupling cavity from different angles. Figure 4 Image (a) is a 3D view of the whole. Figure 4 (b) is the front view. Figure 4 (c) is a side view. Figure 4 (d) is a top view. As shown in the figure, the sound source excitation interface is set at a pole on the sphere, and multiple through holes are evenly distributed on the sphere.

[0074] Figure 5 This is a schematic diagram of the structure of the multi-channel cuboid coupling cavity provided in the embodiments of this application, as shown below. Figure 5 As shown, Figure 5 Images (a) through (d) showcase the multi-channel cuboid coupling cavity from different angles. Figure 5 Image (a) is a 3D view of the whole. Figure 5 (b) is the front view. Figure 5 (c) is a side view. Figure 5 The top view is shown in Figure d. As shown, the sound source excitation interface is located on the top plane, and two through holes are provided on each of the other four side planes.

[0075] In this embodiment, the multi-channel coupling cavity is designed with a regular geometric shape, which facilitates processing and assembly, enhances the mechanical stability of the multi-channel coupler, reduces manufacturing and integration difficulty and cost, and improves aesthetics. The equidistant distribution helps to form a relatively uniform sound field region near the microphone mounting plane, simplifies the sound field model, optimizes the sound field within the cavity, and minimizes sound pressure level and phase measurement errors caused by differences in microphone position.

[0076] In some embodiments, the multi-channel coupling cavity is provided with an acoustic conduit connected to a through hole, the acoustic conduit being used to direct the excitation signal to a microphone embedded in the through hole.

[0077] The acoustic conduit is a channel structure with a specific geometry (such as a straight tube or a tapered tube) that is processed (e.g., through drilling or 3D printing) or installed (e.g., embedded inside a multi-channel coupling cavity) within the multi-channel coupling cavity. In the embodiments of this application, the acoustic conduit is a dedicated channel connecting the sound source excitation interface and the through-hole where the microphone is located, transmitting sound wave energy in a controllable manner.

[0078] For example, each acoustic conduit is independently connected between the sound source excitation interface and a specific through hole. That is, multiple independent acoustic conduits of the same size extend radially from the sound source excitation interface. Each microphone has only one acoustic conduit connected to the bottom of its through hole, and after the microphone is embedded in the through hole, the microphone diaphragm is facing the outlet of the acoustic conduit, so that each microphone has a dedicated and independent sound signal transmission path.

[0079] It should be noted that during the design process, the interface between the acoustic duct and the microphone through-hole must be strictly acoustically sealed to ensure that sound waves do not leak into other cavities of the multi-channel coupling cavity, thereby achieving true directional guidance.

[0080] In this embodiment, by introducing an acoustic conduit network, each microphone to be calibrated acquires an excitation signal through an independent acoustic conduit, avoiding the mixing of reflected or diffracted signals from other channels, eliminating acoustic crosstalk between microphones, and greatly improving the independence and accuracy of sensitivity calibration for each channel microphone.

[0081] In some embodiments, the multi-channel coupling cavity is made of a flexible material, and the opening size of the through-hole varies under external pressure to accommodate microphones of different sizes.

[0082] Among them, flexible materials are materials with a certain elastic deformation capacity that can return to their original shape after the external force is removed. The opening size of the through hole is the inner diameter of the inlet of the through hole on the multi-channel coupling cavity used to embed the microphone, and this size determines the diameter of the microphone shell that can be accommodated.

[0083] For example, when the diameter of the microphone housing to be calibrated is larger than the opening size of the through hole, when the microphone is inserted into the through hole, the flexible material undergoes a certain amount of elastic deformation under the action of external force, the inner diameter of the through hole expands, and tightly wraps around and clamps the microphone housing.

[0084] In one specific implementation, the main body of the multi-channel coupling cavity is integrally cast from a single piece of high-density, low-sound-transmission acoustic silicone. Acoustic conduits connecting the sound source excitation interface and the microphone through-holes are pre-embedded or machined inside. The sound source excitation interface is sealed and bonded to the main body of the silicone multi-channel coupling cavity via a rigid component (such as a rigid flange), ensuring stable input of the excitation signal without affecting the flexible deformation of the through-holes.

[0085] It should be noted that, considering that the multi-channel coupling cavity also needs to have a certain rigidity to resist easy deformation, flexible materials with gradient hardness or composite hardness can be used. For example, the material density and hardness of the main body of the multi-channel coupling cavity are relatively high, while the material hardness around the through holes is relatively low.

[0086] This application embodiment, by employing flexible materials, overcomes the limitations of multi-channel calibration systems on microphone specifications, greatly enhancing the versatility and application range of multi-channel couplers, meeting diverse testing needs, and is particularly suitable for laboratories or service centers with various types of microphones.

[0087] In some embodiments, the signal acquisition device includes a multi-channel preamplifier electrically connected to each microphone.

[0088] Among them, the multi-channel preamplifier can be regarded as a device that integrates multiple independent amplification units. Each amplification unit corresponds to a microphone channel and is used to linearly amplify the weak microphone electrical signal to an amplitude suitable for subsequent acquisition.

[0089] For example, the output of each microphone is connected to a corresponding input channel on the multi-channel preamplifier via a cable (such as a coaxial cable). For instance, 16 microphones embedded in multi-channel coupling cavities are connected to the 16 input interfaces of the 16-channel preamplifier via 16 independent shielded cables. The multi-channel preamplifier is connected to electronics 22 via a high-speed data bus (such as USB, Thunderbolt, or PCIe).

[0090] In this embodiment, a multi-channel preamplifier significantly improves the signal-to-noise ratio of the microphone's acoustic response signal, eliminates inter-channel phase errors caused by the asynchronous clocks of multiple independent single-channel amplifiers, and achieves precise synchronous acquisition of multi-channel signals. Furthermore, using a single integrated multi-channel device to replace multiple independent single-channel amplifiers reduces the complexity and integration difficulty of the multi-channel microphone calibration system.

[0091] In some embodiments, the multi-channel microphone calibration system further includes an embedded sensor array for real-time monitoring of the sound pressure distribution within the multi-channel coupling cavity; transmitting the monitoring results corresponding to the sound pressure distribution to an electronic device; and correspondingly, the electronic device is also used to dynamically adjust the excitation parameters of the acoustic calibrator based on the monitoring results.

[0092] The embedded sensor array consists of a group of miniature acoustic sensors integrated into the inner wall or specific key locations (such as the center or corners of the cavity's sound field) of the multi-channel coupled cavity. These sensors are used to sense the sound pressure at different points within the cavity in real time. The monitoring results are information obtained after processing the raw data collected by the embedded sensor array. These results include, but are not limited to, the maximum and minimum sound pressure levels within the cavity, the standard deviation of the sound pressure levels, and the sound field uniformity index. The embedded sensor array communicates with electronic devices via independent signal lines or data buses.

[0093] The electronic device automatically and in real time controls the acoustic calibrator based on the monitored sound field characteristics (i.e., the monitoring results), changing the parameters of its output excitation signal. The parameters may include the output amplitude (sound pressure level), frequency components, sweep rate, or signal duration.

[0094] For example, in irregularly shaped multi-channel coupled cavities, strong local standing waves are easily excited at specific frequencies (especially high frequencies), resulting in extremely uneven sound pressure distribution within the cavity. This causes microphones at different locations to receive significantly different sound pressure levels, severely compromising calibration accuracy. In this scenario, the electronic device controls the acoustic calibrator to begin a standard linear frequency sweep, monitoring the sound pressure distribution within the cavity in real time through an embedded sensor array and calculating a sound field uniformity index. Suppose that when the frequency sweep reaches a certain frequency f1, the electronic device detects a sharp deterioration in the sound field uniformity index, indicating the presence of strong standing waves. The electronic device can then promptly adjust the excitation parameters, for example, rapidly reducing the output amplitude near f1 and sweeping the frequency band at a faster rate.

[0095] This embodiment utilizes fully automated optimization calibration, eliminating the need for manual judgment and repeated trial and error. Simultaneously, it avoids the risk of overloading the precision microphone due to excessively high local sound pressure levels, thus enhancing calibration safety.

[0096] Next, this application also provides a multi-channel microphone calibration method, applied to an electronic device in the multi-channel microphone calibration system described in the above embodiments. Figure 6 This is a flowchart illustrating the multi-channel microphone calibration method provided in the embodiments of this application, as shown below. Figure 6 As shown, the multi-channel microphone calibration method includes:

[0097] S601, Control the input of the set excitation signal to the sound source excitation interface of the multi-channel coupler.

[0098] For example, the user sets the parameters of the excitation signal through the software interface of the electronic device or automatically by the program. The parameters are not limited to signal type (such as a 1kHz sine wave, linear sweep signal, logarithmic sweep signal, or white noise), signal amplitude, and duration. Then, by clicking "Start Calibration," the software sends a command to the acoustic calibrator, which is activated and emits a standard acoustic excitation signal corresponding to the above parameters into the multi-channel coupling cavity of the multi-channel coupler. For example, a sinusoidal acoustic excitation signal with a sound pressure level of 94dB, a corresponding sound pressure value of 1Pa, and a frequency of 250Hz.

[0099] S602. Obtain the amplified acoustic response signals of each microphone in response to the excitation signal from the signal acquisition device.

[0100] Each microphone embedded in the through-hole of the multi-channel coupler generates a corresponding weak electrical signal (i.e., acoustic response signal) according to its own characteristics.

[0101] For example, the weak electrical signal from each microphone is transmitted directly to a multi-channel preamplifier in the signal acquisition device via a wire. The preamplifier immediately amplifies the signal from each channel, boosting it to a suitable voltage level for acquisition and converting it into a low-output-impedance signal to enhance anti-interference capability. The amplified multi-channel analog signals are then sent to a multi-channel analog-to-digital converter in the signal acquisition device for synchronous sampling, converting them into digital signals. The electronic equipment acquires the amplified digital sequence of acoustic response signals corresponding to each microphone.

[0102] S603. Based on the amplified acoustic response signal and excitation signal, calibrate the sensitivity of the corresponding microphone.

[0103] Assuming the amplitude (i.e. voltage value) of the acoustic response signal of microphone a is 12.5mV, then the sensitivity of microphone a is 0.0125V / 1Pa = 0.0125V / Pa.

[0104] In this embodiment, a multi-channel coupler is used to transmit the sound pressure of a standard sound source to each microphone, enabling simultaneous acquisition and calibration of signals from multiple microphones. The calibration process is simple, eliminating the need to insert each standard microphone individually into the calibrator coupling cavity. Furthermore, simultaneous calibration of multiple microphones within the same calibration environment reduces calibration errors.

[0105] In summary, this application has at least the following advantages:

[0106] First, a multi-channel coupler is introduced into the multi-channel microphone calibration system. This coupler simultaneously transmits the excitation signal to multiple microphones, enabling parallel calibration of multiple microphones. Calibration time decreases linearly with the number of microphones, significantly improving calibration efficiency. Furthermore, the multiple microphones to be calibrated are housed in the same multi-channel coupling cavity, ensuring a consistent calibration environment and eliminating calibration errors caused by environmental differences, thus improving the consistency of calibration data. In addition, this system minimizes manual operations such as repeatedly plugging and unplugging microphones, avoiding human error and improving the objectivity and repeatability of calibration results.

[0107] Second, the first-order resonant frequency of the multi-channel coupling cavity is designed to be greater than twice the frequency corresponding to the excitation signal. This suppresses the resonance of the multi-channel coupling cavity, ensures the uniformity of the sound field within the working frequency band, and thus guarantees the accuracy of the multi-channel microphone calibration.

[0108] Third, by designing the multi-channel coupling cavity as a modular unit, multiple modules can be combined to adapt to different numbers of microphone calibration requirements, improving the flexibility and versatility of the multi-channel coupler, meeting diverse testing needs, and reducing manufacturing costs and cycle time. Furthermore, if a prefab is damaged due to impact or other reasons, only the damaged prefab needs to be replaced, reducing maintenance costs.

[0109] Fourth, by introducing an acoustic conduit network, each microphone to be calibrated obtains an excitation signal through an independent acoustic conduit, avoiding the mixing of reflected or diffracted signals from other channels, eliminating acoustic crosstalk between microphones, and greatly improving the independence and accuracy of sensitivity calibration for each channel microphone.

[0110] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 7 As shown, the electronic device 70 provided in this embodiment includes at least one processor 701 and a memory 702. Optionally, the electronic device 70 further includes a communication component 703. The processor 701, memory 702, and communication component 703 are connected via a bus 704.

[0111] In a specific implementation, at least one processor 701 executes computer execution instructions stored in memory 702, causing at least one processor 701 to perform the above-described method.

[0112] The specific implementation process of processor 701 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0113] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0114] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0115] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0116] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0117] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0118] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0119] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0120] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0121] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0122] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0123] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, 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 of the various embodiments of this 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.

[0124] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0125] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A multi-channel microphone calibration system, characterized by, The system comprises a multi-channel coupler, an electronic device, an acoustic calibrator and a signal acquisition device connected with the electronic device, the multi-channel coupler comprises a multi-channel coupling cavity and a sound source excitation interface arranged on the multi-channel coupling cavity, the sound source excitation interface is used for connecting the acoustic calibrator, and a plurality of through holes for embedding microphones are arranged on the multi-channel coupling cavity; wherein: The acoustic calibrator is used for inputting a set of excitation signals to the sound source excitation interface of the multi-channel coupler under the control of the electronic device; The multi-channel coupler is used for transmitting the excitation signals to the microphones embedded in the plurality of through holes; The signal acquisition device is used for collecting sound response signals of each microphone to the excitation signals and amplifying the sound response signals; The electronic device is used for acquiring the amplified sound response signals corresponding to each microphone; and calibrating the sensitivity of the corresponding microphone according to the amplified sound response signals and the excitation signals. The first-order resonance frequency of the multi-channel coupling cavity is greater than a preset multiple of the frequency corresponding to the excitation signal, and the preset multiple is greater than or equal to 2.

2. The multi-channel microphone calibration system of claim 1, wherein, The multi-channel coupling cavity is assembled by using modular prefabricated blocks to adapt to different numbers of microphones.

3. The multi-channel microphone calibration system of claim 1, wherein, The multi-channel coupling cavity is a cube, a cuboid or a sphere; and / or the through holes are equidistantly distributed.

4. The multi-channel microphone calibration system of any one of claims 1 to 3, wherein, The multi-channel coupling cavity is provided with an acoustic conduit connected with the through holes, and the acoustic conduit is used for directing the excitation signals to the microphones embedded in the through holes.

5. The multi-channel microphone calibration system of any one of claims 1 to 3, wherein, The multi-channel coupling cavity is made of a flexible material, and the opening size of the through holes changes under the adjustment of external pressure to adapt to different specifications and sizes of microphones.

6. The multi-channel microphone calibration system of any one of claims 1 to 3, wherein, The signal acquisition device comprises a multi-channel preamplifier electrically connected with each microphone.

7. The multi-channel microphone calibration system of any one of claims 1 to 3, wherein, The system further comprises an embedded sensor array, which is used for monitoring the sound pressure distribution in the multi-channel coupling cavity in real time; and transmitting monitoring results corresponding to the sound pressure distribution to the electronic device.

8. The multi-channel microphone calibration system of any one of claims 1 to 3, wherein, Correspondingly, the electronic device is further used for dynamically adjusting the excitation parameters of the acoustic calibrator according to the monitoring results. The electronic device applied to the multi-channel microphone calibration system in any one of claims 1 to 8, the multi-channel microphone calibration method comprises:

9. A method of calibrating a multi-channel microphone, the method comprising: controlling input of a set of excitation signals to the sound source excitation interface of the multi-channel coupler; acquiring amplified sound response signals of each microphone to the excitation signals from a signal acquisition device; calibrating the sensitivity of the corresponding microphone according to the amplified sound response signals and the excitation signals. The system comprises a memory and a processor; 10. An electronic device, comprising: The memory stores computer execution instructions; The processor executes the computer execution instructions stored in the memory, so that the processor executes the method in claim 9. ​ ​

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