System and method for testing directivity of microphone

Abstract

The microphone directivity test system is arranged in an anechoic chamber and comprises a placement table, a microphone, a microphone, a microphone, a microphone, a microphone and a loudspeaker, the sound source device is arranged on the placement table and is used for emitting sound waves; the microphone is arranged on the placing table and is used for receiving sound waves; the supporting device is arranged on the placing table and is used for movably supporting the microphone; and the calibration device is arranged on the upper side of the placement table and is used for calibrating the position of the microphone. According to the main technical scheme and the main effects, the system can accurately control the relative positions of the microphone, the sound source and the rotating seat by installing the laser and the marking line and controlling the movement of the rotating seat, the positioning accuracy of the microphone is ensured in each test, and the accuracy reduction caused by positioning errors in a traditional method is avoided.

Description

Technical Field

[0001] The invention relates to the field of sound transmission testing, and in particular to a microphone directivity testing system and method. Background Art

[0002] The directional response of a microphone refers to the response of the microphone sensitivity to the change of the incident angle of the sound wave in a specified plane and at a specified frequency. This response that changes with angle can be plotted as a graph to represent the microphone sensitivity determined by the change of direction and frequency within a 360° range. The directional response of a microphone is an important indicator of the microphone. The directional response of the microphone is required in standards such as GB / T 3785.1-2023 "Electroacoustic Sound Level Meter" and GB 9660 "Aircraft Noise Environmental Quality Standards for Areas Surrounding Airports".

[0003] The development of microphone directivity test equipment is an important progress in the field of acoustic measurement technology. It provides an accurate tool for evaluating the performance of microphones in different sound field environments. As a key component for sound signal acquisition, microphones play a vital role in many fields such as communication, recording, and environmental monitoring. Their directivity, that is, the sensitivity of the microphone to the direction of the sound source, directly affects the quality and accuracy of sound signal acquisition.

[0004] When testing the directivity of a microphone, the main axis of the microphone needs to be perpendicular to the center of the rotation axis, and at the same time, the diaphragm of the microphone and the axis of rotation must be in the same plane.

[0005] Traditional microphone directivity testing methods have many limitations. The directivity test of the microphone has high requirements on the accuracy of the spatial positioning of the microphone and its position during movement. Existing equipment cannot achieve accurate and rapid positioning adjustment. Summary of the invention

[0006] Purpose of the invention: The purpose of the present invention is to solve the problem that the equipment in the prior art cannot achieve accurate and fast positioning adjustment, and to provide a microphone directivity test system and method, so that the design of the equipment allows for fast automatic adjustment under different test conditions without a lot of manual intervention, thereby saving operation time and improving the fluency of the experiment.

[0007] Technical solution:

[0008] The present application proposes a microphone directivity test system, which is arranged in an anechoic chamber and includes:

[0009] Placement table;

[0010] A sound source device, disposed on the placement table, for emitting sound waves;

[0011] A microphone, arranged on the placement table, for receiving sound waves;

[0012] A supporting device, arranged on the placement table, for movably supporting the microphone;

[0013] The calibration device is arranged on the upper side of the placement table and is used to calibrate the position of the microphone.

[0014] Preferably, the supporting device comprises an amplifier fixing sleeve, a preamplifier connected to the microphone is fixed in the amplifier fixing sleeve, and a marking line is provided on the amplifier fixing sleeve;

[0015] The calibration device comprises a laser arranged in the anechoic chamber and is used for calibrating the microphone through a marking line and an end face of the microphone.

[0016] Preferably, the supporting device comprises a movable platform disposed on the placement table and moving, and a supporting rod connected to the movable platform and capable of being raised and lowered, wherein the upper end of the supporting rod is hingedly connected to the amplifier fixing sleeve via a damping mechanism.

[0017] Preferably, a point laser is connected to the upper side of the mobile platform, and the laser emitted by the point laser can be aimed at the diaphragm of the microphone.

[0018] Preferably, a positioning wheel is provided at the bottom end of the mobile platform, and a guide rail matching the positioning wheel is provided on the placement table.

[0019] Preferably, a top straight line laser is provided on the upper side wall of the anechoic chamber, a horizontal straight line laser is provided on the side wall of the anechoic chamber, the marking line includes a top marking line and a side marking line, the laser emitted by the top straight line laser can overlap with the top marking line, and the laser emitted by the horizontal straight line laser can overlap with the side marking line.

[0020] Preferably, the support rod includes a first support rod and a second support rod, one end of the first support rod is fixed to the mobile platform, the first support rod is a hollow structure, the second support rod can be inserted into the first support rod, the upper end of the first support rod is connected to a contraction piece, and a threaded cylinder is provided on the outer side of the contraction piece through a threaded sleeve, so that the threaded cylinder squeezes the second support rod to fix it when it rotates on the contraction piece.

[0021] Preferably, the contraction member includes a threaded tube and an elastic sheet, the threaded tube is connected to the first support rod, the elastic sheets are provided in plurality and are respectively distributed along the circumferential direction with respect to one end of the threaded tube away from the first support rod, and the elastic sheets gradually become thinner and gather in the direction away from the threaded tube.

[0022] Preferably, the mobile platform includes a base and a rotating seat, the lower end of the base is connected to the positioning wheel, the lower end of the rotating seat is rotatably connected to the base, and the upper end of the rotating seat is respectively connected to the support rod and the point laser.

[0023] Preferably, a microphone directivity testing method is also proposed, which is used to implement the microphone directivity testing system described in the above embodiment, and is characterized in that:

[0024] In the anechoic chamber, the microphone can be rotated at multiple angles by moving the supporting device. While the microphone can be rotated at multiple angles, the laser is turned on to align with the marking line on the amplifier fixing sleeve. When the laser emitted by the laser coincides with the marking line, the laser calibration is completed.

[0025] When testing the directivity of a microphone, first turn on the sound source device, set the sound source signal to the sound pressure level and frequency to be tested, and then preheat for 15 minutes before testing.

[0026] First, record the sound pressure level measured by the microphone when the sound source device is incident at 20°. This sound pressure level is the reference angle sound pressure level of the microphone's directivity response.

[0027] The rotating base is rotated at the same angle, and the sound pressure level of the microphone at the corresponding angle is recorded for each rotation;

[0028] Repeat the above operation until the microphone to be tested is rotated 360°;

[0029] The directional response of the microphone at that frequency point is obtained by subtracting the sound pressure level recorded at each angle from the sound pressure level at the reference angle;

[0030] Change the frequency of the sound source and use the same test method to measure the directional response of microphone 3 at different frequencies;

[0031] Wherein, causing the rotating seat to rotate according to the same angle includes:

[0032] The rotating seat is driven to rotate by a driving motor wirelessly connected to the remote control, and the rotation gears are 5° for the first gear and 10° for the second gear.

[0033] Preferably, a top straight line laser is provided on the upper side wall of the anechoic chamber, a horizontal straight line laser is provided on the side wall of the anechoic chamber, the marking lines include a top marking line and a side marking line, the laser emitted by the top straight line laser can coincide with the top marking line, the laser emitted by the horizontal straight line laser can coincide with the side marking line, when the laser emitted by the top straight line laser coincides with the top marking line, the horizontal calibration of the microphone is achieved, and when the laser emitted by the horizontal straight line laser coincides with the side marking line, the vertical calibration of the microphone is achieved.

[0034] Beneficial effects: By installing lasers and marking lines, as well as high-precision motion control of the rotating seat, the system can accurately control the relative positions of the microphone, sound source and rotating seat. In each test, the positioning accuracy of the microphone is guaranteed, avoiding the decrease in accuracy caused by positioning errors in traditional methods.

[0035] Traditional equipment has problems such as inaccurate rotation angle and complicated test process. This device ensures precise control of rotation angle, test height, etc. through optimized design, avoiding test errors caused by insufficient precision.

[0036] Through the use of laser positioning and marking lines, the system allows operators to complete position adjustment and angle setting more intuitively, avoiding the complicated manual adjustment steps in traditional testing and making operation more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the structure of the muffler chamber from one side of the interior of the present invention;

[0038] Figure 2 It is a schematic diagram of the structure of the microphone inside the anechoic chamber from the upper side of the present invention;

[0039] Figure 3 It is a schematic diagram of the structure of the shrinking member and the threaded barrel of the present invention.

[0040] Reference numerals:

[0041] 1. Placement table; 2. Sound source device; 3. Microphone; 4. Amplifier fixing sleeve; 5. Preamplifier; 6. Rotating seat; 7. Point laser; 8. Positioning wheel; 9. Guide rail; 10. Top straight line laser; 11. Horizontal straight line laser; 12. Top marking line; 13. Side marking line; 14. First support rod; 15. Second support rod; 16. Contraction piece; 17. Threaded cylinder; 18. Threaded tube; 19. Elastic sheet; 20. Base; 21. Side view marking line of sound source device; 22. Top view marking line of sound source device. DETAILED DESCRIPTION

[0042] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the specific embodiments of the accompanying drawings.

[0043] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0044] In view of the problems existing in the existing technology, such as Figure 1-3 As shown, a microphone directivity test system is arranged in an anechoic chamber, comprising

[0045] Placement table 1;

[0046] A sound source device 2 is disposed on the placement table 1 and is used to emit sound waves;

[0047] A microphone 3 is provided on the placement platform 1 and is used to receive sound waves;

[0048] A supporting device, provided on the placement platform 1, for movably supporting the microphone 3;

[0049] The calibration device is arranged on the upper side of the placement table 1 and is used to calibrate the position of the microphone 3 .

[0050] The supporting device comprises an amplifier fixing sleeve 4, a preamplifier 5 connected to the microphone 3 is fixed in the amplifier fixing sleeve 4, and a marking line is provided on the amplifier fixing sleeve 4;

[0051] The calibration device comprises a laser disposed in the anechoic chamber, and is used for calibrating the microphone 3 via a marking line and an end face of the microphone 3 .

[0052] Specifically, the microphone 3 is precisely adjusted in the anechoic chamber. When the microphone 3 is fixed, the microphone 3 is arranged on one side of the preamplifier 5. The preamplifier 5 is used to receive the sound signal through the microphone 3 and then transmit it to other devices. The microphone 3 is calibrated by calibrating the preamplifier 5. Since the preamplifier 5 is fixed on the amplifier fixing sleeve 4, the preamplifier 5 and the microphone 3 are calibrated by aligning the laser with the marking line on the amplifier fixing sleeve 4. In addition, the calibration is also performed by aligning the laser with one end of the microphone 3.

[0053] In some specific embodiments, the supporting device includes a movable platform disposed on the placement table 1 and a support rod connected to the movable platform and capable of being raised and lowered. The upper end of the support rod is hinged to the amplifier fixing sleeve 4 via a damping.

[0054] Specifically, in order to facilitate the calibration of the preamplifier 5, the amplifier fixing sleeve 4 to which the preamplifier 5 is fixed can rotate freely on the support rod, and its specific rotation structure can be implemented using a hinge with damping, so that the amplifier fixing sleeve 4 can be fixed at any angle when rotating.

[0055] In some specific embodiments, a point laser 7 is connected to the upper side of the mobile platform, and the laser emitted by the point laser 7 can be aimed at the diaphragm of the microphone 3 .

[0056] Specific, combined Figure 1 The diaphragm is arranged at one end of the microphone 3. When the microphone 3 slides horizontally, the laser A generated by the point laser 7 is turned on to irradiate one end of the microphone 3, that is, the diaphragm, so as to realize the calibration of the horizontal position of the microphone 3.

[0057] In some specific embodiments, a positioning wheel 8 is provided at the bottom end of the mobile platform, and a guide rail 9 matching the positioning wheel 8 is provided on the placement table 1 .

[0058] Specifically, when the microphone 3 is calibrated in horizontal position, the positioning wheel 8 slides stably and directionally on the guide rail 9 .

[0059] In some specific embodiments, a top line laser 10 is provided on the upper side wall of the anechoic chamber, a horizontal line laser 11 is provided on the side wall of the anechoic chamber, the marking line includes a top marking line 12 and a side marking line 13, the laser emitted by the top line laser 10 can overlap with the top marking line 12, and the laser emitted by the horizontal line laser 11 can overlap with the side marking line 13.

[0060] In some specific embodiments, a side wall of the sound source device is provided with a side view marking line 21 of the sound source device, and an upper side wall of the sound source device is provided with a top view marking line 22 of the sound source device.

[0061] Specifically, when the horizontal line laser 11 is turned on, a horizontal laser is generated, that is, Figure 1 The laser B in the microphone 3 is raised and lowered and rotated, and when the laser in the horizontal direction coincides with the marking line of the sound source device 2 and the side marking line 13 at the same time, the calibration of the microphone 3 in the vertical direction is completed;

[0062] exist Figure 2In the figure, the vertical laser C is emitted by the top straight line laser 10. When the laser C coincides with the top mark line 22 and the top mark line 12 of the sound source device 2, the microphone 3 is rotated in the horizontal direction for positioning and calibration.

[0063] In some specific embodiments, the support rod includes a first support rod 14 and a second support rod 15, one end of the first support rod 14 is fixed to the mobile platform, the first support rod 14 is a hollow structure, the second support rod 15 can be inserted into the first support rod 14, the upper end of the first support rod 14 is connected with a contraction piece 16, and the outer side of the contraction piece 16 is provided with a threaded tube 17 through a threaded sleeve, so that the threaded tube 17 can squeeze the second support rod 15 to be fixed when it rotates on the contraction piece 16.

[0064] Specifically, the second support rod 15 is lifted and lowered in the first support rod 14 , and the height of the second support rod 15 is limited by the cooperation of the contraction piece 16 and the threaded cylinder 17 .

[0065] In some specific embodiments, the contraction member 16 includes a threaded tube 18 and an elastic sheet 19, the threaded tube 18 is connected to the first support rod 14, and the elastic sheet 19 is provided in plurality and respectively distributed along the circumferential direction with respect to one end of the threaded tube 18 away from the first support rod 14, and the elastic sheet 19 gradually becomes thinner and gathers in the direction away from the threaded tube 18.

[0066] Specifically, when the second support rod 15 is not fixed, it can rotate inside the first support rod 14 to make the microphone 3 rotate horizontally. When the second support rod 15 is inserted into the first support rod 14 and needs to be fixed, the threaded barrel 17 is sleeved on the outside of the threaded tube 18 and rotates downward. The threaded barrel 17 is a T-shaped structure. One end of the threaded barrel 17 gradually squeezes the elastic sheet 19. In the process of the threaded barrel 17 moving downward, the force of the elastic sheet 19 squeezing the second support rod 15 becomes greater, thereby fixing the second support rod 15.

[0067] In some specific embodiments, the mobile platform includes a base 20 and a rotating base 21, the lower end of the base 20 is connected to the positioning wheel 8, the lower end of the rotating base 21 is rotatably connected to the base 20, and the upper end of the rotating base 21 is respectively connected to the support rod and the point laser 7.

[0068] Specifically, the rotating seat 6 can rotate on the base 20, and the axis of rotation is the laser optical fiber A of the point laser 7, which is convenient for the microphone 3 to rotate when calibrating in the horizontal direction.

[0069] In some specific embodiments, a microphone directivity testing method is also proposed, which is used to implement the microphone directivity testing system as described above.

[0070] In the anechoic chamber, the microphone 3 can be rotated at multiple angles by moving the supporting device. While the microphone 3 can be rotated at multiple angles, the laser is turned on to align with the marking line on the amplifier fixing sleeve 4. When the laser emitted by the laser coincides with the marking line, the laser calibration is completed.

[0071] When testing the directivity of the microphone, first turn on the sound source device 2, set the sound source signal to the sound pressure level and frequency to be tested, and then preheat for 15 minutes before testing.

[0072] First, record the sound pressure level measured by microphone 3 when the sound source device is incident at 20°. This sound pressure level is the reference angle sound pressure level of the directivity response of microphone 3.

[0073] The rotating base is rotated at the same angle, and the sound pressure level of the microphone at the corresponding angle is recorded for each rotation;

[0074] Repeat the above operation until the microphone to be tested is rotated 360°;

[0075] The directional response of the microphone 3 at the frequency point is obtained by subtracting the sound pressure level recorded at each angle from the sound pressure level at the reference angle;

[0076] Change the frequency of the sound source and use the same test method to measure the directional response of microphone 3 at different frequencies;

[0077] Wherein, making the rotating seat 6 rotate according to the same angle includes:

[0078] The rotating seat is driven to rotate by a driving motor wirelessly connected to the remote control, and the rotation gears are 5° for the first gear and 10° for the second gear.

[0079] In some specific embodiments, a top straight line laser 10 is provided on the upper side wall of the anechoic chamber, a horizontal straight line laser 11 is provided on the side wall of the anechoic chamber, the marking lines include a top marking line 12 and a side marking line 13, the laser emitted by the top straight line laser 10 can coincide with the top marking line 12, the laser emitted by the horizontal straight line laser 11 can coincide with the side marking line 13, when the laser emitted by the top straight line laser 10 coincides with the top marking line 12, the horizontal calibration of the microphone 3 is achieved, and when the laser emitted by the horizontal straight line laser 11 coincides with the side marking line 13, the vertical calibration of the microphone 3 is achieved.

[0080] The above is only a specific implementation of the embodiment of the present invention, but the protection scope of the embodiment of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiment of the present invention should be included in the protection scope of the embodiment of the present invention. Therefore, the protection scope of the embodiment of the present invention should be based on the protection scope of the claims.

Claims

1. A microphone directivity test system, arranged in an anechoic chamber, characterized in that: include: Placement table (1); A sound source device (2) is disposed on the placement platform (1) and is used to emit sound waves; A microphone (3) is disposed on the placement platform (1) and is used to receive sound waves; A supporting device, arranged on the placement platform (1), and used for movably supporting the microphone (3); A calibration device is arranged on the upper side of the placement table (1) and is used to calibrate the position of the microphone (3). The support device comprises an amplifier fixing sleeve (4), a preamplifier (5) connected to the microphone (3) is fixed in the amplifier fixing sleeve (4), and a marking line is provided on the amplifier fixing sleeve (4); The calibration device comprises a laser arranged in the anechoic chamber, and is used to calibrate the microphone (3) via a marking line and an end face of the microphone (3).

2. A microphone directivity test system according to claim 1, characterized in that: The support device comprises a movable platform arranged on the placement table (1) and a support rod connected to the movable platform and capable of being raised and lowered. The upper end of the support rod is hingedly connected to the amplifier fixing sleeve (4) via a damping mechanism.

3. A microphone directivity test system according to claim 2, characterized in that: A point laser (7) is connected to the upper side of the mobile platform, and the laser light emitted by the point laser (7) can be aimed at the diaphragm of the microphone (3).

4. A microphone directivity testing system according to claim 3, characterized in that: A positioning wheel (8) is provided at the bottom end of the mobile platform, and a guide rail (9) matching the positioning wheel (8) is provided on the placement table (1).

5. A microphone directivity testing system according to claim 1, characterized in that: A top line laser (10) is provided on the upper side wall of the anechoic chamber, and a horizontal line laser (11) is provided on the side wall of the anechoic chamber. The marking lines include a top marking line (12) and a side marking line (13) respectively provided on the top and side of the amplifier fixing sleeve (4). The laser light emitted by the top line laser (10) can overlap with the top marking line (12), and the laser light emitted by the horizontal line laser (11) can overlap with the side marking line (13).

6. A microphone directivity testing system according to claim 2, characterized in that: The support rod comprises a first support rod (14) and a second support rod (15); one end of the first support rod (14) is fixed to the mobile platform; the first support rod (14) is a hollow structure; the second support rod (15) can be inserted into the first support rod (14); the upper end of the first support rod (14) is connected with a contraction piece (16); a threaded barrel (17) is provided on the outer side of the contraction piece (16) through a threaded sleeve, so that the threaded barrel (17) squeezes the second support rod (15) to be fixed when rotating on the contraction piece (16).

7. A microphone directivity testing system according to claim 6, characterized in that: The contraction member (16) comprises a threaded tube (18) and an elastic sheet (19); the threaded tube (18) is connected to the first support rod (14); a plurality of elastic sheets (19) are provided and are respectively distributed along a circumferential direction with respect to an end of the threaded tube (18) away from the first support rod (14); the elastic sheets (19) gradually become thinner and gather in a direction away from the threaded tube (18).

8. A microphone directivity testing system according to claim 4, characterized in that: The mobile platform comprises a base (20) and a rotating base (6); the lower end of the base (20) is connected to a positioning wheel (8); the lower end of the rotating base (6) is rotatably connected to the base (20); and the upper end of the rotating base (6) is respectively connected to a support rod and a point laser (7).

9. A microphone directivity testing method, used for using the microphone (3) directivity testing system according to any one of claims 1 to 8, characterized in that: In the anechoic chamber, the microphone (3) can be rotated at multiple angles by moving the supporting device. While the microphone (3) can be rotated at multiple angles, the laser is turned on to align with the marking line on the amplifier fixing sleeve (4). When the laser light emitted by the laser coincides with the marking line, the laser calibration is completed. When testing the directivity of the microphone, first turn on the sound source device (2), set the sound source signal to the sound pressure level and frequency to be tested, and then preheat for 15 minutes before testing. First, the sound pressure level measured by the microphone (3) when the sound source device (2) is incident at 0° is recorded, and the sound pressure level is the reference angle sound pressure level of the directional response of the microphone (3); The rotating seat (6) is rotated according to the same angle, and the sound pressure level of the microphone at the corresponding angle is recorded during each rotation; Repeat the above operation until the microphone to be tested is rotated 360°; The directional response of the microphone (3) at the frequency point is obtained by taking the difference between the sound pressure level recorded at each angle and the sound pressure level at the reference angle; Change the frequency of the sound source and use the same test method to measure the directional response of the microphone (3) at different frequencies.

10. A microphone directivity testing method according to claim 9, characterized in that: A top straight line laser (10) is provided on the upper side wall of the anechoic chamber, and a horizontal straight line laser (11) is provided on the side wall of the anechoic chamber. The marking lines include a top marking line (12) and a side marking line (13) respectively provided on the top and side of the amplifier fixing sleeve (4). The laser emitted by the top straight line laser (10) can overlap with the top marking line (12), and the laser emitted by the horizontal straight line laser (11) can overlap with the side marking line (13). When the laser emitted by the top straight line laser (10) overlaps with the top marking line (12), the microphone (3) is calibrated in the horizontal direction. When the laser emitted by the horizontal straight line laser (11) overlaps with the side marking line (13), the microphone (3) is calibrated in the vertical direction.

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