Microphone testing device and microphone testing method

Abstract

This application discloses a microphone testing device and method, relating to the field of microphone testing, and more particularly, to the testing of microphone arrays for artificial intelligence speakers. A specific implementation scheme is as follows: the microphone testing device includes an audio analyzer, a mute box, and a light source disposed within the mute box; the mute box is used to house a micro-electromechanical system (MEMS) microphone array to be tested; the light source and the MEMS microphone array are disposed relative to each other; and an audio analyzer is connected to the MEMS microphone array, the audio analyzer being used to obtain the audio signal output by the MEMS microphone array and to display the spectral information of the audio signal. Embodiments of this application contribute to improved microphone design and product quality.

Description

Technical Field

[0001] The present application relates to the field of electronic testing technology, in particular to the field of microphone testing, and specifically to a microphone testing device and a microphone testing method. Background Art

[0002] With the popularity of smart voice devices, the performance requirements for microphones are becoming increasingly higher. Currently, MEMS (Micro-Electro-Mechanical System) microphone arrays, which are compact and have stable performance, have been widely used and have become the mainstream microphone in smart voice devices.

[0003] Acoustic performance testing is a crucial step in the design and improvement of microphones. Currently, microphone testing primarily involves comparing the microphone's output signal in a sound-generating environment with the source signal to measure the microphone's sound quality. Summary of the Invention

[0004] The present application provides a microphone testing device and a microphone testing method, which can be applied to the testing of the microphone array of a voice device such as an artificial intelligence speaker.

[0005] According to one aspect of the present application, there is provided a microphone testing device, comprising an audio analyzer, a sound-absorbing box, and a light source disposed in the sound-absorbing box;

[0006] The anechoic box is used to place the MEMS microphone array to be tested;

[0007] The light source and the MEMS microphone array are arranged opposite to each other;

[0008] The audio analyzer is connected to the MEMS microphone array. The audio analyzer is used to obtain the audio signal output by the MEMS microphone array and display spectrum information of the audio signal.

[0009] According to another aspect of the present application, a microphone testing method is provided. The method is based on the microphone testing device provided in any embodiment of the present application, and the method includes:

[0010] The MEMS microphone array is placed in a sound-absorbing box, and the MEMS microphone array is illuminated by a light source in the sound-absorbing box;

[0011] Setting the illumination and / or flickering frequency of the light source through a light source controller of the light source;

[0012] The audio analyzer receives a first audio signal corresponding to light illumination and / or flicker frequency output by the MEMS microphone array, and displays frequency spectrum information of the first audio signal.

[0013] According to another aspect of the present application, there is provided a microphone testing device, comprising: an audio analyzer, a sound-absorbing box, and a light source disposed in the sound-absorbing box;

[0014] The mute box is used to place the microphone to be tested;

[0015] The light source and the microphone are arranged opposite to each other;

[0016] The audio analyzer is connected to the microphone and is used to obtain the audio signal output by the microphone and display spectrum information of the audio signal.

[0017] According to the embodiments of the present application, since the sound-absorbing enclosure provides a quiet environment and both the light source and microphone are placed within the enclosure, the microphone can output an audio signal that superimposes light noise on the background signal. Using an audio analyzer to display the spectrum of this audio signal can intuitively demonstrate the magnitude of light noise introduced to the microphone by the ambient light environment, helping to improve microphone design and enhance product quality.

[0018] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are provided to facilitate a better understanding of the present invention and do not constitute a limitation of the present application.

[0020] Figure 1 is a schematic diagram according to the first embodiment of the present application;

[0021] Figure 2 is a schematic diagram according to the second embodiment of the present application;

[0022] Figure 3 is a schematic diagram according to the third embodiment of the present application;

[0023] Figure 4 is a schematic diagram according to a fourth embodiment of the present application;

[0024] Figure 5 is a schematic diagram of spectrum information of a first audio signal in an embodiment of the present application;

[0025] Figure 6 is a schematic diagram of spectrum information of a second audio signal in an embodiment of the present application;

[0026] Figure 7 This is a schematic diagram showing the superimposed display of spectrum information in an embodiment of the present application;

[0027] Figure 8 It is a schematic diagram according to the sixth embodiment of the present application. DETAILED DESCRIPTION

[0028] The following description of exemplary embodiments of the present application is made in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding. These details should be considered as merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0029] Figure 1 FIG. 1 shows a schematic diagram of a microphone testing device according to an embodiment of the present application. Figure 1 As shown, the device includes an audio analyzer 11 , a sound-absorbing box 12 and a light source 13 arranged in the sound-absorbing box 12 .

[0030] The anechoic box 12 is used to place the MEMS microphone array 14 to be tested. The light source 13 is arranged opposite to the MEMS microphone array 14.

[0031] The audio analyzer 11 is connected to the MEMS microphone array 14 . The audio analyzer 11 is used to obtain the audio signal output by the MEMS microphone array 14 and display the frequency spectrum information of the audio signal.

[0032] In the microphone testing device provided in the present embodiment, since the anechoic chamber 12 provides a quiet environment and both the light source 13 and the MEMS microphone array 14 are located within the anechoic chamber 12, the MEMS microphone array 14 can output an audio signal that superimposes optical noise on the background signal. Using the audio analyzer 11 to display the spectral information of this audio signal can intuitively demonstrate the magnitude of the optical noise introduced by the light environment to the MEMS microphone array 14, helping to improve the design of the MEMS microphone array 14 and enhance product quality.

[0033] Exemplarily, the MEMS microphone array is a microphone array in an artificial intelligence voice device, such as an artificial intelligence speaker.

[0034] In an exemplary embodiment, referring to Figure 2 The microphone testing device may further include a light source controller 17 connected to the light source 13. The light source controller 17 may be used to control various parameters of the light source 13, such as illumination, flicker frequency, and / or color temperature.

[0035] The light source controller 17 is provided in the microphone testing device, which can test the optical noise of the MEMS microphone array 14 in different light environments according to different testing requirements, and provide more basis for the design improvement of the MEMS microphone array 14.

[0036] Exemplarily, the light source 13 includes an LED planar light source.

[0037] The LED planar light source can place the MEMS microphone array 14 in a uniformly illuminated light environment, better simulating the daily light environment. Therefore, the microphone testing device can provide a more practical basis for the design improvement of the MEMS microphone array 14.

[0038] In an exemplary embodiment, the distance between the light source 13 and the MEMS microphone array 14 is adjustable.

[0039] By adjusting the distance between the light source 13 and the MEMS microphone array 14, it is convenient to take and place the microphone array 14 and adjust the test parameters during the test, which is beneficial for users to set the light environment according to test requirements and improve the application flexibility of the microphone test device.

[0040] For example, a mounting position for placing the MEMS microphone array 14 and an adjustment mechanism for adjusting the distance between the mounting position and the light source 13 can be provided in the soundproofing box 12. By adjusting the distance between the light source 13 and the mounting position, the distance between the light source 13 and the MEMS microphone array 14 can be adjusted.

[0041] This exemplary embodiment provides a specific solution for adjusting the distance between the MEMS microphone array and the light source, which is conducive to improving the application flexibility of the microphone testing device.

[0042] Exemplarily, the microphone testing device also includes an illuminance meter. Since the illuminance is not only related to the output of the light source 13, but also to the distance between the light source 13 and the illumination plane, the illuminance meter can detect the illuminance under different distance conditions. Therefore, when the distance between the light source 13 and the MEMS microphone array 14 is adjustable, the illuminance meter is used to accurately detect the illuminance, which can facilitate the user to adjust the illuminance to the target value. The illuminance meter can be fixed in the soundproof box 12 and be in the same plane as the MEMS microphone array 14. The illuminance meter can also be a portable, movable device. During the test process, the illuminance meter can be placed in the installation position first. After adjusting the various parameters of the light source 13 using the illuminance meter, the illuminance meter can be removed and the MEMS microphone array can be placed in the installation position.

[0043] As an exemplary embodiment, refer to Figure 2 The microphone testing device may further include a signal format conversion module 16 , which is connected between the MEMS microphone array 14 and the audio analyzer 11 and is used to perform format conversion on the audio signal output by the MEMS microphone array.

[0044] For example, when the audio signal output by the MEMS microphone array 14 is a PDM (Pulse Density Modulation) signal and the signal input by the audio analyzer 11 is a PCM (Pulse Code Modulation) signal, a PDM to PCM signal format conversion module 16 is provided between the MEMS microphone array 14 and the audio analyzer 11;

[0045] For another example, when the audio signal output by the MEMS microphone array 14 is an analog signal and the signal input by the audio analyzer 11 is a PDM signal, an analog-to-PDM signal format conversion module 16 is provided between the MEMS microphone array 14 and the audio analyzer 11 .

[0046] By providing the signal format conversion module 16 , the audio analyzer 11 can be flexibly selected and various MEMS microphone arrays 14 can be tested, thereby improving the application flexibility of the microphone testing device.

[0047] Exemplarily, the microphone testing device includes a power supply box 19 . The power supply box 19 includes a power supply module 18 . The power supply module 18 is used to respectively power the audio analyzer 11 and the MEMS microphone array 14 . The signal format conversion module 16 may be disposed in the power supply box 19 .

[0048] Exemplarily, the frequency spectrum information displayed by the audio analyzer 11 is an FFT (Fast Fourier Transform) spectrum.

[0049] In practical applications, the microphone testing device is not limited to testing the MEMS microphone array 14, but can also be used to test other microphones such as ECM (Electret Condenser Micphone). That is, the embodiment of the present application also provides a microphone testing device, see Figure 3 , the device includes: an audio analyzer 11, a muffler box 12 and a light source 13 arranged in the muffler box 12;

[0050] The muffler box 12 is used to place the microphone 15 to be tested;

[0051] The light source 13 and the microphone 15 are arranged opposite to each other;

[0052] The audio analyzer 11 is connected to the microphone 15 , and is used to obtain the audio signal output by the microphone 15 and display frequency spectrum information of the audio signal.

[0053] Because sound-absorbing enclosure 12 provides a quiet environment and both light source 13 and microphone 15 are housed within it, microphone 15 can output an audio signal composed of optical noise superimposed on the background signal. Using audio analyzer 11 to display the audio signal's spectrum provides a visual representation of the amount of optical noise introduced to microphone 15 by the ambient light, helping to improve the design and quality of microphone 15.

[0054] The embodiment of the present application also provides a microphone testing method. Figure 4 A schematic diagram of a microphone testing method according to an embodiment of the present application is shown. The method is implemented based on the microphone testing device provided in any embodiment of the present application, including:

[0055] Step S11, placing the MEMS microphone array in a sound-absorbing box, and irradiating the MEMS microphone array with a light source in the sound-absorbing box;

[0056] Step S12: setting the illumination and / or flickering frequency of the light source through the light source controller of the light source;

[0057] The audio analyzer receives a first audio signal corresponding to light illumination and / or flicker frequency output by the MEMS microphone array, and displays frequency spectrum information of the first audio signal.

[0058] The microphone testing method provided in the embodiment of the present application, since the sound-absorbing box can provide a quiet environment, places the MEMS microphone array in a sound-absorbing box equipped with a light source, which can make the MEMS microphone array output an audio signal with light noise superimposed on the background signal. The frequency spectrum information of the audio signal is displayed using an audio analyzer, which can intuitively show the size of the light noise brought to the microphone by the light environment. In addition, by setting the illuminance and / or flicker frequency of the light source, various light environments can be simulated to test the light noise of the MEMS microphone array in a specific light environment according to actual test requirements, providing a rich basis for the design and improvement of the MEMS microphone array and improving product quality.

[0059] In actual application, the steps of the microphone testing method can be set with reference to any implementation of the microphone testing device. In addition, there is no specific order in which the steps are performed.

[0060] For example, a light source controller is used to set the light source's illuminance to a target value of 1600 lx or 1700 lx, and the light source's flicker frequency to 50 Hz or 60 Hz. During this process, the distance between the light source and the mounting point is adjusted using the adjustment mechanism in the sound-absorbing box, for example, between 3 mm and 5 mm. Simultaneously, a illuminance meter is used to measure the illuminance, making it easy to set the target illuminance. The MEMS microphone array is then placed in the sound-absorbing box, and the adjustment mechanism is used to maintain the same distance between the mounting point and the light source as when the light source was set.

[0061] For example, the MEMS microphone array is first placed in a sound-absorbing box, and then the light source controller is used to set the illumination and flashing frequency of the light source.

[0062] In a specific application example, the flashing frequency of the light source is 50 Hz, the illuminance is 1700 lx, and the spectrum information of the first audio signal displayed by the audio analyzer is as follows: Figure 5 According to the spectrum information, it can be determined that the amplitude of the fundamental wave near the flicker frequency of 50 Hz is about 15 dB, and the amplitude of the harmonics at 100 Hz is about 10 dB.

[0063] Exemplarily, the audio analyzer may further receive a second audio signal output by the MEMS microphone array when the light source is turned off, and the audio analyzer may display spectrum information of the second audio signal.

[0064] In actual application, the audio analyzer can first acquire the first audio signal and display the corresponding spectrum information, and then acquire the second audio signal and display the corresponding spectrum information; or the audio analyzer can first acquire the second audio signal and display the corresponding spectrum information, and then acquire the first audio signal and display the corresponding spectrum information.

[0065] In an application example where the light source has a flicker frequency of 50 Hz and an illuminance of 1700 lx, the spectrum information of the second audio signal displayed by the audio analyzer is as follows: Figure 6 shown.

[0066] In this exemplary embodiment, the second audio signal can be regarded as the background signal of the MEMS microphone. By comparing the spectrum information of the first audio signal and the spectrum information of the second audio signal, the optical noise situation can be more clearly understood.

[0067] Exemplarily, the frequency spectrum information of the first audio signal and the frequency spectrum information of the second audio signal are displayed in a superimposed manner.

[0068] In the application example where the light source has a flicker frequency of 50 Hz and an illuminance of 1700 lx, Figure 7As shown, after the spectrum information 10 of the first audio signal and the spectrum information 20 of the second audio signal are superimposed and displayed, it can be seen that at 50 Hz and 100 Hz, the amplitude of the first audio signal is significantly greater than the amplitude of the second audio signal. Therefore, there is optical noise in the MEMS microphone array.

[0069] By superimposing and displaying the spectrum information of the first audio signal and the spectrum information of the second audio signal, it is convenient to compare the spectrum information of the first audio signal and the spectrum information of the second audio signal.

[0070] For example, Figure 8 As shown, the microphone test method also includes:

[0071] Step S13: determining the amplitude of the fundamental wave of the first audio signal according to the spectrum information of the first audio signal;

[0072] Step S14: If the fundamental wave amplitude is greater than the preset threshold, it is determined that optical noise exists in the MEMS microphone array.

[0073] For example, according to Figure 5 and Figure 7 Based on the spectrum information, it can be determined that the fundamental amplitude of the first audio signal output by the MEMS microphone under test, corresponding to a flicker frequency of 50 Hz and an illuminance of 1700 lx, is 15 dB. If the preset threshold is 5 dB, based on the fact that 15 dB > 5 dB, it can be determined that the MEMS microphone has optical noise.

[0074] By using this exemplary embodiment, it is possible to determine whether the MEMS microphone array has optical noise, which helps to evaluate whether the MEMS microphone array needs to be improved and provides a basis for design improvements of the MEMS microphone array.

[0075] Exemplarily, the harmonic amplitude of the first audio signal can also be determined based on the spectrum information of the first audio signal. For example, when the flickering frequency of the light source is 50 Hz, the harmonic amplitudes of 100 Hz, 150 Hz, 200 Hz, etc. can be determined based on the spectrum information.

[0076] For example, the optical noise level of the MEMS microphone array can be determined using the fundamental amplitude of the first audio signal and multiple preset thresholds. For example, using 15dB, 10dB, and 5dB, the optical noise level of the MEMS microphone array can be determined as severe optical noise greater than 15dB, significant optical noise less than or equal to 15dB and greater than 10dB, and general optical noise less than or equal to 10dB and greater than 5dB. Different measures can be used to improve the MEMS microphone array based on different optical noise levels.

[0077] For example, since optical noise in MEMS microphone arrays primarily comes from light-sensitive components within the ASIC (Application Specific Integrated Circuit), for both general and significant optical noise, the structural design of the MEMS microphone array can be improved, such as by avoiding placing the ASIC under a light-transmitting acoustic port. Alternatively, low-transmittance vinyl can be added or replaced over the acoustic port to prevent excessive light from projecting onto the ASIC. For severe optical noise, the circuit design within the ASIC can be improved, such as by replacing components with different parameters or types or modifying the circuit structure.

[0078] In practical applications, the microphone testing method is not limited to testing MEMS microphone arrays, but can also be used to test other microphones such as ECM (Electret Condenser Micphone).

[0079] According to the technical solution of the embodiments of this application, since the sound-absorbing box provides a quiet environment and both the light source and the microphone are placed within the box, the microphone can output an audio signal that superimposes light noise on the background signal. Using an audio analyzer to display the spectral information of this audio signal can intuitively demonstrate the level of light noise introduced to the microphone by the light environment, helping to improve microphone design and product quality.

[0080] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this application can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this application can be achieved. This is not a limitation herein.

[0081] The above specific embodiments do not constitute a limitation on the scope of protection of this application. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A microphone testing device comprising an audio analyzer, a sound-absorbing box, and a light source disposed in the sound-absorbing box; The anechoic box is used to place the MEMS microphone array to be tested; The light source is arranged opposite to the MEMS microphone array; The audio analyzer is connected to the MEMS microphone array, and is used to obtain the audio signal output by the MEMS microphone array and display the frequency spectrum information of the audio signal; The device further comprises: A light source controller, connected to the light source, for controlling the light source to set different illuminations according to different test requirements; Wherein, the muffler box is provided with a mounting position and an adjustment mechanism; The mounting position is used to place the MEMS microphone array; The adjustment mechanism is used to adjust the distance between the installation position and the light source; The device further comprises: An illuminometer, fixed in the anechoic box and located in the same plane as the MEMS microphone array, for detecting light intensity at different distances; When testing the MEMS microphone array, the user adjusts the distance between the mounting position and the light source through the adjustment mechanism, detects the illuminance through the illuminometer to adjust the illuminance to a target value, and tests the optical noise of the MEMS microphone array when the illuminance is the target value.

2. The apparatus according to claim 1, further comprising: A signal format conversion module is connected between the MEMS microphone array and the audio analyzer, and is used to perform format conversion on the audio signal output by the MEMS microphone array.

3. The device according to any one of claims 1 to 2, wherein: The light source includes an LED planar light source.

4. A microphone testing method, the microphone testing method being based on the microphone testing device according to any one of claims 1 to 3, the microphone testing method comprising: placing the MEMS microphone array in a sound-absorbing box, and illuminating the MEMS microphone array with the light source in the sound-absorbing box; Setting the illumination of the light source by a light source controller of the light source; The audio analyzer receives a first audio signal corresponding to the light intensity and output by the MEMS microphone array, and displays frequency spectrum information of the first audio signal.

5. The method according to claim 4, wherein The audio analyzer receives a second audio signal output by the MEMS microphone array during a period when the light source is turned off, and displays spectrum information of the second audio signal.

6. The method according to claim 5, wherein: The frequency spectrum information of the first audio signal and the frequency spectrum information of the second audio signal are displayed in a superimposed manner.

7. The method according to claim 5, further comprising: determining a fundamental wave amplitude of the first audio signal according to frequency spectrum information of the first audio signal; If the fundamental wave amplitude is greater than a preset threshold, it is determined that optical noise exists in the MEMS microphone array.

8. A microphone testing device, characterized in that: include: An audio analyzer, a sound-absorbing box, and a light source disposed in the sound-absorbing box; The muffler box is used to place the microphone to be tested; The light source is arranged opposite to the microphone; The audio analyzer is connected to the microphone, and is used to obtain the audio signal output by the microphone and display the frequency spectrum information of the audio signal; The device further comprises: A light source controller, connected to the light source, for controlling the light source to set different illuminations according to different test requirements; An illuminometer, fixed in the muffler box and located in the same plane as the microphone array, for detecting light intensity at different distances; Wherein, the muffler box is provided with a mounting position and an adjustment mechanism; The installation position is used to place the microphone; The adjustment mechanism is used to adjust the distance between the installation position and the light source; When testing the microphone array, the user adjusts the distance between the mounting position and the light source through the adjustment mechanism, detects the illuminance through the illuminometer to adjust the illuminance to a target value, and tests the optical noise of the microphone array when the illuminance is the target value.

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