Microphone signal-to-noise ratio testing device and microphone signal-to-noise ratio testing system

Abstract

The invention belongs to the technical field of microphones, and particularly relates to a microphone signal-to-noise ratio testing device and a microphone signal-to-noise ratio testing system. The microphone signal-to-noise ratio testing device comprises an inner box, an outer box, a gas buffer piece and an inflation and deflation mechanism, a separation cavity is formed by a gap between the outer wall of the inner box and the inner wall of the outer box, and the gas buffer piece is located in the separation cavity; the inflation and deflation mechanism has a vacuumizing mode and a constant pressure mode, in the vacuumizing mode, the inflation and deflation mechanism is used for pumping gas in the partition cavity into an inflation cavity of the gas buffer part, the gas buffer part expands and is supported between the outer wall of the inner box and the inner wall of the outer box, and at least part of the gas buffer part supports the bottom wall of the inner box; and in the constant-pressure mode, the gas buffer piece is communicated with the separation cavity. According to the microphone signal-to-noise ratio testing device, the total amount of gas in the inflation cavity and the separation cavity is basically unchanged, and the dust accumulation efficiency is effectively reduced due to the extremely small ventilation amount, so that the testing environment of the microphone signal-to-noise ratio testing device can still keep basically the same background noise even if the microphone signal-to-noise ratio testing device is subjected to frequent tests for multiple times, and the testing accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microphones, and in particular relates to a microphone signal-to-noise ratio testing device and a microphone signal-to-noise ratio testing system. Background Art

[0002] Traditional microphone signal-to-noise ratio tests are mostly conducted in a simulated vacuum environment. Since sound is transmitted through a medium, a vacuum environment is the best means of sound insulation. Using a vacuum environment as the microphone signal-to-noise ratio test environment is beneficial for significantly reducing the background noise of the microphone signal-to-noise ratio test, thereby improving the accuracy of the signal-to-noise ratio test.

[0003] The existing microphone signal-to-noise ratio test is conducted in a soundproof box, which includes an outer box and an inner box arranged in the outer box, and a shock-isolating pad is arranged between the outer box and the inner box. During the signal-to-noise ratio test, a vacuum pump extracts the gas between the inner box and the outer box. When it is necessary to take the microphone out of the inner box or put the microphone into the inner box, the vacuum pump transports external gas to the space between the inner box and the outer box or balances the air pressure between the inner box and the outer box through a pressure relief valve.

[0004] However, the above-mentioned sound insulation box needs to be frequently inflated and deflated during frequent testing, and external air accompanied by dust and impurities will enter between the inner box and the outer box. The dust and impurities are very easy to adhere to the seismic isolation pad. After a long time, the solid medium on the seismic isolation pad gradually increases, or the dust and impurities adhered to the box wall between the inner box and the outer box increase. The accumulation of dust will increase the solid medium between the inner box and the outer box that can be used to transmit sound waves, resulting in changes in the sound transmission effect, affecting the background noise of the microphone's signal-to-noise ratio test environment, and reducing the test accuracy. Summary of the invention

[0005] The technical problem to be solved by the present invention is: for the existing sound insulation box, the accumulation of dust will increase the solid medium that can be used to transmit sound waves between the inner box and the outer box, resulting in changes in the sound transmission effect, affecting the background noise of the microphone signal-to-noise ratio test environment, and reducing the test accuracy. A microphone signal-to-noise ratio test device and a microphone signal-to-noise ratio test system are provided.

[0006] In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides a microphone signal-to-noise ratio test device, comprising an inner box, an outer box, a gas buffer and a gas charging and discharging mechanism, wherein the inner box is located inside the outer box, the outer wall of the inner box and the inner wall of the outer box form a compartment, and the gas buffer is located in the compartment; The gas buffer has an inflation cavity inside, and the inflation and deflation mechanism has a vacuum mode and a constant pressure mode. In the vacuum mode, the inflation and deflation mechanism is used to pump the gas in the compartment into the inflation cavity of the gas buffer, and the gas buffer expands and is supported between the outer wall of the inner box and the inner wall of the outer box, and at least part of the gas buffer supports the bottom wall of the inner box; in the constant pressure mode, the gas buffer is connected to the compartment.

[0007] Optionally, the inflation and deflation mechanism comprises an air pump, a compartment pipe and a buffer pipe, the air pump has a first interface and a second interface, the compartment pipe connects the first interface and the compartment, and the buffer pipe connects the second interface and the gas buffer; In the vacuum mode, the gas in the compartment is pumped into the gas buffer by the air pump; in the constant pressure mode, the gas buffer, the compartment pipe, the buffer pipe and the compartment are connected.

[0008] Optionally, the inflation and deflation mechanism further comprises a multi-way valve and a one-way valve, the multi-way valve having a first valve port, a second valve port and a third valve port, the compartment pipe is connected to the first valve port via a first pipe, the buffer pipe is connected to the second valve port via a second pipe, and the third valve port is connected to the second interface via a third pipe; the one-way valve is installed at the first interface so that the gas can only flow from the compartment to the first interface; In the vacuuming mode, the second valve port is connected to the third valve port, and the gas in the compartment flows into the gas buffer through the compartment pipeline, the first interface, the second interface, the third valve port, the second valve port, and the buffer pipeline in sequence; In the constant pressure mode, the first valve port is connected to the second valve port, and the gas in the inflation cavity of the gas buffer flows into the compartment cavity through the buffer pipe, the second valve port, the first valve port, and the compartment cavity pipe in sequence.

[0009] Optionally, the inflation and deflation mechanism further comprises a first tracheal valve and a second tracheal valve, wherein the first tracheal valve is connected to the compartment pipe and the first interface, and the second tracheal valve is connected to the buffer pipe and the second interface; The air pump is a bidirectional air pump. In the constant pressure mode, the gas in the inflation cavity of the gas buffer is pumped into the compartment through the air pump.

[0010] Optionally, the gas buffer is an air spring, a plurality of the gas buffers are provided, a plurality of the buffer pipes are provided, and each of the gas buffers is connected to a buffer pipe; The inner box includes an inner box top plate, an inner box bottom plate, and an inner box side panel connected between the inner box top plate and the inner box bottom plate, and the outer box includes an outer box top plate, an outer box bottom plate, and an outer box side panel connected between the outer box top plate and the outer box bottom plate; Among the plurality of gas buffers, in the vacuum mode, some of the gas buffers are supported between the inner box bottom plate and the outer box bottom plate, and some of the gas buffers are supported between the inner box side panels and the outer box side panels.

[0011] Optionally, the gas buffer is an airbag, a top side of the airbag is provided with a receiving groove, and the bottom of the inner box is fixed in the receiving groove; The airbag is provided with a plurality of connection ports, the buffer pipes are provided with a plurality of connection ports, and each of the connection ports is connected to a buffer pipe.

[0012] Optionally, a limiting plate is installed in the accommodating groove, the limiting plate has a limiting groove opening toward the inner box, the limiting groove is adapted to the shape of the inner box, and the bottom of the inner box is fixed in the limiting groove.

[0013] Optionally, the inflation and deflation mechanism also includes a buffer air row, on which a first buffer air port and multiple second buffer air ports are provided, the second interface of the air pump is connected to the first buffer air port, and multiple buffer pipes are provided, and each of the second buffer air ports is connected to a buffer pipe.

[0014] Optionally, the inflation and deflation mechanism further comprises a base having a containing cavity, the air pump, the cavity partition pipe and the buffer pipe are installed in the containing cavity, and the outer box is placed on the top surface of the base.

[0015] On the other hand, an embodiment of the present invention further provides a microphone signal-to-noise ratio testing system, comprising a testing instrument and the above-mentioned microphone signal-to-noise ratio testing device, wherein the testing instrument is used to test the signal-to-noise ratio of the microphone installed in the inner box.

[0016] The microphone signal-to-noise ratio test device of the present invention, in the vacuuming mode, the gas charging and discharging mechanism pumps the gas in the compartment cavity into the gas charging cavity of the gas buffer, and the gas buffer expands and supports the inner box, so that the gas buffer is inflated while the compartment cavity is vacuumed. In the constant pressure mode, the gas in the gas charging cavity of the gas buffer flows into the compartment cavity, so that the total amount of gas in the gas charging cavity and the compartment cavity remains basically unchanged, and the gas only flows in the gas charging cavity and the compartment cavity through the gas charging and discharging mechanism, and there is no need to fill the outside gas into the compartment cavity or only a small amount of outside gas needs to be filled into the compartment cavity. The extremely small ventilation volume effectively reduces the dust accumulation efficiency on the gas buffer, the inner wall of the outer box and the outer wall of the inner box, so that even after the microphone signal-to-noise ratio test device is tested many times and frequently, its test environment can still maintain basically the same background noise, reduce test variables, and improve the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a microphone signal-to-noise ratio testing device provided in the first embodiment of the present invention; Figure 2 yes Figure 1 A magnified view of part A; Figure 3 for Figure 1 Gas flow diagram of microphone signal-to-noise ratio test device in vacuum mode; Figure 4 for Figure 1 Gas flow diagram of microphone signal-to-noise ratio test device in constant pressure mode; Figure 5 A schematic structural diagram of a microphone signal-to-noise ratio testing device provided in a second embodiment of the present invention.

[0018] The reference numerals in the specification are as follows: 100, outer box; 101, inner box door; 200, inner box; 201, outer box door; 1, compartment; 2, gas buffer; 3, limit plate; 4, charging and discharging mechanism; 41, air pump; 411, first interface; 412, second interface; 42, compartment pipe; 43, buffer pipe; 44, base; 5, multi-way valve; 51, first valve port; 52, second valve port; 53, third valve port; 6, one-way valve; 7, first pipe; 8, second pipe; 9, third pipe; 10, compartment air exhaust; 11, buffer air exhaust; 12, first air pipe valve; 13, second air pipe valve. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figure 1 As shown, the first embodiment of the present invention provides a microphone signal-to-noise ratio testing device, including an inner box 200, an outer box 100, a gas buffer 2 and a charging and discharging mechanism 4, the inner box 200 is located in the outer box 100, the outer wall of the inner box 200 and the inner wall of the outer box 100 form a compartment 1, and the gas buffer 2 is located in the compartment 1.

[0021] The gas buffer 2 has an inflatable cavity inside, and the gas filling and deflation mechanism 4 is used to pump the gas in the compartment 1 into the inflatable cavity of the gas buffer 2. The gas buffer 2 expands and is supported between the outer wall of the inner box 200 and the inner wall of the outer box 100, and at least part of the gas buffer 2 supports the bottom wall of the inner box 200. In the constant pressure mode, the gas buffer 2 is connected to the compartment 1.

[0022] Specifically, after the microphone is placed in the inner box 200, when the signal-to-noise ratio of the microphone needs to be tested, the inflation and deflation mechanism 4 is switched to the vacuum mode to pump the gas in the compartment 1 into the inflation chamber of the gas buffer 2, so that the gas buffer 2 is inflated while the compartment 1 is vacuumed. The gas buffer 2 expands and pushes the inner box 200 in a preset direction.

[0023] The sound insulation effect of the vacuum chamber 1 is better, which is beneficial to reducing the background noise of the microphone signal-to-noise ratio test. The expanded gas buffer 2 serves as a contact unit between the inner box 200 and the outer box 100. The sound waves generated by the mechanical vibration of the outer box 100 are only transmitted through the elastic shell and the internal gas of the gas buffer 2. On the one hand, the gas buffering effect is much higher than that of solid elastic parts. On the other hand, the sound wave transmission efficiency of the gas medium is lower than that of the solid medium. Therefore, the sound wave transmission efficiency between the outer box 100 and the inner box 200 is greatly reduced, thereby effectively reducing the background noise of the microphone signal-to-noise ratio test device and improving the accuracy of the signal-to-noise ratio test results.

[0024] Moreover, since the air pressure in the compartment 1 is turned toward negative pressure, an air pressure difference is formed between the outside and the inside of the gas buffer 2, which is beneficial for the outward expansion of the gas buffer 2 after the filling and discharging mechanism 4 delivers gas into the inflation cavity, thereby improving the inflation efficiency of the gas buffer 2 and improving the efficiency of forming the vacuum environment of the compartment 1, thereby improving the testing efficiency.

[0025] When the test is completed, the inflation and deflation mechanism 4 switches to the constant pressure mode, the inflation chamber of the gas buffer 2 is connected to the compartment 1, and the gas compressed in the inflation chamber of the gas buffer 2 flows into the negative pressure compartment 1 until the air pressure in the inflation chamber is the same as the air pressure in the compartment 1.

[0026] Compared with the traditional vacuum forming method, which requires continuous external ventilation and causes continuous accumulation of dust and impurities in the outer box 100, the microphone signal-to-noise ratio testing device of the present invention, the total amount of gas in the inflation chamber and the compartment 1 of the gas buffer 2 remains basically unchanged, and the gas only flows in the inflation chamber and the compartment 1 through the inflation and deflation mechanism 4. The extremely small ventilation volume effectively reduces the dust accumulation efficiency on the gas buffer 2, the inner wall of the outer box 100 and the outer wall of the inner box 200. After the initial test determines the background noise, subsequent multiple tests can keep it basically the same as the precise original background noise, so that the microphone signal-to-noise ratio testing device can maintain basically the same background noise in the test environment even after multiple frequent tests, thereby reducing test variables and improving test accuracy.

[0027] The microphone signal-to-noise ratio test device of the present invention, in the vacuum mode, the gas charging and discharging mechanism 4 pumps the gas in the compartment 1 into the gas charging chamber of the gas buffer 2, and the gas buffer 2 expands and supports the inner box 200, so as to inflate the gas buffer 2 while the compartment 1 is vacuumed. In the constant pressure mode, the gas compressed in the gas charging chamber of the gas buffer 2 flows into the compartment 1, so that the total amount of gas in the gas charging chamber and the compartment 1 remains basically unchanged, and the gas only flows in the gas charging chamber and the compartment 1 through the gas charging and discharging mechanism 4, and there is no need to charge the external gas into the compartment 1 or only a small amount of external gas needs to be charged into the compartment 1. The extremely small ventilation volume effectively reduces the dust accumulation efficiency on the gas buffer 2, the inner wall of the outer box 100 and the outer wall of the inner box 200, so that even after the microphone signal-to-noise ratio test device is tested many times and frequently, its test environment can still maintain basically the same background noise, reduce test variables, and improve the test accuracy.

[0028] In one embodiment, if Figure 1 and Figure 3 As shown, the inflation and deflation mechanism 4 includes an air pump 41, a compartment pipe 42 and a buffer pipe 43. The air pump 41 has a first interface 411 and a second interface 412. The compartment pipe 42 connects the first interface 411 and the compartment 1, and the buffer pipe 43 connects the second interface 412 and the gas buffer 2.

[0029] like Figure 3 As shown, the arrows in the figure indicate the gas flow direction. In the vacuum mode, the gas in the compartment 1 is pumped into the gas buffer 2 by the air pump 41.

[0030] like Figure 4 As shown, the arrows in the figure indicate the direction of gas flow. In the constant pressure mode, the gas buffer 2, the compartment pipe 42, the buffer pipe 43 and the compartment 1 are connected, and the gas compressed in the gas buffer 2 flows into the compartment 1 after passing through the buffer pipe 43 and the compartment pipe 42 in turn until the air pressure in the compartment 1 is balanced with the air pressure in the inflation chamber.

[0031] In other embodiments, the air pump 41 may be replaced by an air compressor.

[0032] In one embodiment, if Figure 1 and Figure 2 As shown, the gas charging and discharging mechanism 4 further includes a multi-way valve 5 and a one-way valve 6. The multi-way valve 5 has a first valve port 51, a second valve port 52 and a third valve port 53. The compartment pipe 42 is connected to the first valve port 51 through a first pipe 7, the buffer pipe 43 is connected to the second valve port 52 through a second pipe 8, and the third valve port 53 is connected to the second interface 412 through a third pipe 9. The one-way valve 6 is installed at the first interface 411 so that the gas can only flow from the compartment 1 to the first interface 411.

[0033] like Figure 3 As shown, in the vacuum mode, the second valve port 52 and the third valve port 53 are connected, and the gas in the compartment 1 flows into the gas buffer 2 through the compartment pipe 42, the first interface 411, the second interface 412, the third valve port 53, the second valve port 52, and the buffer pipe 43 in sequence.

[0034] like Figure 4 As shown, in the constant pressure mode, the first valve port 51 and the second valve port 52 are connected, and the gas in the inflation cavity of the gas buffer 2 flows into the compartment 1 through the buffer pipe 43, the second valve port 52, the first valve port 51, and the compartment pipe 42 in sequence.

[0035] With this design, the air pump 41 can only transport the gas from the compartment 1 to the inflation chamber in one direction. The one-way air pump 41 has a simple structure, a small size, occupies a small space, and is easy to arrange.

[0036] In one embodiment, if Figure 1 As shown, the gas buffer 2 is an airbag, a receiving groove is provided on the top side of the airbag, and the bottom of the inner box 200 is fixed in the receiving groove.

[0037] The airbag is provided with a plurality of connection ports, and a plurality of buffer pipes 43 are provided, and each connection port is connected to a buffer pipe 43 .

[0038] The supporting surface of the airbag supporting the inner box 200 is larger, the airbag has a better buffering effect on the inner box 200, and the stability of the inner box 200 is higher.

[0039] Since the inflation cavity in the airbag has a large space, the airbag is connected to multiple buffer pipes 43, and the gas extracted from the compartment 1 by the air pump 41 can be simultaneously transported to the airbag through multiple buffer pipes 43, thereby improving the inflation efficiency of the airbag and thus improving the test efficiency.

[0040] In one embodiment, a limiting plate 3 is installed in the accommodating groove, the limiting plate 3 has a limiting groove opening toward the inner box 200, the limiting groove is adapted to the shape of the inner box 200, and the bottom of the inner box 200 is fixed in the limiting groove.

[0041] Since the airbag has a poor efficiency in limiting the inner box 200 when the inner box 200 is directly placed on the upper surface of the airbag, the inner box 200 is likely to slide relative to the upper surface of the airbag when the airbag is inflated. Therefore, a limiting plate 3 is fixed on the airbag, and the limiting groove of the limiting plate 3 is used to limit the inner box 200.

[0042] In one embodiment, the limiting plate 3 is an elastic plate, and when the airbag is deflated, the limiting plate 3 can buffer the inner box 200. The limiting plate 3 can be made of rubber.

[0043] In one embodiment, if Figure 1 As shown, it also includes a buffer gas exhaust 11, a first buffer gas port and a plurality of second buffer gas ports are provided on the buffer gas exhaust 11, a second interface 412 of the air pump 41 is connected to the first buffer gas port, a plurality of buffer pipes 43 are provided, and each second buffer gas port is connected to a buffer pipe 43. The plurality of buffer pipes 43 are connected to the second interface 412 of the air pump 41 through a buffer gas exhaust 11 to simplify the pipe connection structure and reduce the occupied space.

[0044] In one embodiment, the inner box 200 and the outer box 100 are both square, and an inner access opening is provided on the top plate of the inner box 200, and an inner box door 101 is installed at the inner access opening. An outer access opening is provided on the top plate of the outer box 100, and an outer box door 201 is installed at the outer access opening, and an operator takes and places the microphone through the inner access opening and the outer access opening.

[0045] In one embodiment, a compartment air discharge 10 is further included, and a first compartment air port and a plurality of second compartment air ports are provided on the compartment air discharge 10, the first compartment air port is connected to a first interface 411 of an air pump 41, a plurality of compartment pipes 42 are provided, and each second compartment air port is connected to a compartment pipe 42. The plurality of compartment pipes 42 are connected to the first interface 411 of the air pump 41 through one compartment air discharge 10, so as to simplify the pipe connection structure and reduce the occupied space.

[0046] In one embodiment, a fourth compartment air port is further provided on the upper surface of the compartment air discharger 10, and the fourth compartment air port is connected to the plurality of second compartment air ports. One end of the first pipe 7 is connected to the first valve port 51 of the three-way valve, and the other end is connected to the fourth compartment air port.

[0047] In one embodiment, two groups of compartment pipes 42 are provided, and the two groups of compartment pipes 42 are respectively provided on opposite sides of the inner box 200 . Accordingly, two groups of second compartment air ports of the compartment air discharger 10 are provided.

[0048] In one embodiment, four groups of buffer pipes 43 are provided, and the four groups of buffer pipes 43 are evenly spaced in the horizontal direction. Correspondingly, four groups of second buffer air ports of the buffer air discharge 11 are provided, and four groups of connecting ports on the airbag are provided.

[0049] In one embodiment, the buffer air exhaust 11 and the compartment air exhaust 10 are both placed horizontally, the air pump 41 is placed on the upper surface of the compartment air exhaust 10 , and the buffer air exhaust 11 is placed on the upper surface of the air pump 41 .

[0050] In one embodiment, the inflation and deflation mechanism 4 further includes a base 44 having a receiving cavity, the air pump 41 , the cavity partition pipe 42 and the buffer pipe 43 are installed in the receiving cavity, and the outer box 100 is placed on the top surface of the base 44 .

[0051] In other embodiments, Figure 5 As shown, it also includes a first tracheal valve 12 and a second tracheal valve 13 . The first tracheal valve 12 connects the compartment pipe 42 and the first interface 411 , and the second tracheal valve 13 connects the buffer pipe 43 and the second interface 412 .

[0052] The air pump 41 is a bidirectional air pump. In the constant pressure mode, the gas in the inflation chamber of the gas buffer 2 is pumped into the compartment 1 through the air pump 41 to improve the efficiency of the gas in the inflation chamber flowing into the compartment 1, so that the air pressure in the inflation chamber and the air pressure in the compartment 1 can be the same as soon as possible. At the same time, the air pump 41 with a bidirectional air pump structure can ensure that the gas always moves back and forth on the same path, further reducing the degree of change in the total amount of gas and the impurity content, and further improving the test efficiency.

[0053] like Figure 5 As shown, the second embodiment of the present invention provides a microphone signal-to-noise ratio testing device. The difference from the first embodiment is that the gas buffer 2 is an air spring, and a plurality of gas buffers 2 are provided.

[0054] A plurality of buffer pipes 43 are provided, and each gas buffer 2 is connected to a buffer pipe 43. The inner box 200 includes an inner box top plate, an inner box 200 bottom plate, and an inner box side panel connected between the inner box top plate and the inner box 200 bottom plate, and the outer box 100 includes an outer box top plate, an outer box bottom plate, and an outer box side panel connected between the outer box top plate and the outer box bottom plate.

[0055] Among the multiple gas buffers 2, in the vacuum mode, some of the gas buffers 2 are supported between the bottom plate of the inner box 200 and the bottom plate of the outer box, and some of the gas buffers 2 are supported between the side panels of the inner box and the side panels of the outer box.

[0056] In one embodiment, four groups of gas buffers 2 are provided, two of which are supported between the bottom plate of the inner box 200 and the bottom plate of the outer box, and the remaining two groups are respectively provided on opposite sides of the inner box side panels.

[0057] In other embodiments, the gas buffer 2 may include an air bag and a plurality of air springs, the air bag being supported between the bottom plate of the inner box 200 and the bottom plate of the outer box, and the plurality of air springs being supported between the side panels of the inner box and the side panels of the outer box.

[0058] In addition, an embodiment of the present invention further provides a microphone signal-to-noise ratio testing system, including a testing instrument and the microphone signal-to-noise ratio testing device in any of the above embodiments, wherein the testing instrument is used to test the signal-to-noise ratio of the microphone installed in the inner box 200 .

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microphone signal-to-noise ratio test device, characterized in that: The invention comprises an inner box (200), an outer box (100), a gas buffer (2) and a gas charging and discharging mechanism (4), wherein the inner box (200) is located inside the outer box (100), a space between an outer wall of the inner box (200) and an inner wall of the outer box (100) forms a compartment (1), and the gas buffer (2) is located in the compartment (1); The gas buffer (2) has an inflatable cavity inside, and the inflating and deflation mechanism (4) has a vacuum mode and a constant pressure mode. In the vacuum mode, the inflating and deflation mechanism (4) is used to pump the gas in the compartment (1) into the inflatable cavity of the gas buffer (2), and the gas buffer (2) expands and is supported between the outer wall of the inner box (200) and the inner wall of the outer box (100), and at least part of the gas buffer (2) supports the bottom wall of the inner box (200); in the constant pressure mode, the gas buffer (2) is connected to the compartment (1).

2. The microphone signal-to-noise ratio test device according to claim 1, characterized in that: The gas charging and discharging mechanism (4) comprises an air pump (41), a compartment pipe (42) and a buffer pipe (43); the air pump (41) has a first interface (411) and a second interface (412); the compartment pipe (42) connects the first interface (411) and the compartment (1); and the buffer pipe (43) connects the second interface (412) and the gas buffer (2); In the vacuum mode, the gas in the compartment (1) is pumped into the gas buffer (2) via the air pump (41); in the constant pressure mode, the gas buffer (2), the compartment pipe (42), the buffer pipe (43) and the compartment (1) are connected.

3. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The inflation and deflation mechanism (4) further comprises a multi-way valve (5) and a one-way valve (6); the multi-way valve (5) has a first valve port (51), a second valve port (52) and a third valve port (53); the compartment pipe (42) is connected to the first valve port (51) via a first pipe (7); the buffer pipe (43) is connected to the second valve port (52) via a second pipe (8); and the third valve port (53) is connected to the second interface (412) via a third pipe (9); the one-way valve (6) is installed at the first interface (411) so that gas can only flow from the compartment (1) to the first interface (411); In the vacuum pumping mode, the second valve port (52) and the third valve port (53) are connected, and the gas in the compartment (1) flows into the gas buffer (2) in sequence through the compartment pipeline (42), the first interface (411), the second interface (412), the third valve port (53), the second valve port (52), and the buffer pipeline (43); In the constant pressure mode, the first valve port (51) and the second valve port (52) are connected, and the gas in the inflation cavity of the gas buffer (2) flows into the compartment cavity (1) via the buffer pipe (43), the second valve port (52), the first valve port (51), and the compartment cavity pipe (42) in sequence.

4. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The inflation and deflation mechanism (4) further comprises a first air pipe valve (12) and a second air pipe valve (13), wherein the first air pipe valve (12) is connected to the compartment pipe (42) and the first interface (411), and the second air pipe valve (13) is connected to the buffer pipe (43) and the second interface (412); The air pump (41) is a bidirectional air pump. In the constant pressure mode, the gas in the inflation cavity of the gas buffer (2) is pumped into the compartment (1) via the air pump (41).

5. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The gas buffer (2) is an air spring, a plurality of the gas buffer (2) are provided, a plurality of the buffer pipes (43) are provided, and each of the gas buffers (2) is connected to a buffer pipe (43); The inner box (200) comprises an inner box top plate, an inner box bottom plate, and an inner box side panel connected between the inner box top plate and the inner box bottom plate, and the outer box (100) comprises an outer box top plate, an outer box bottom plate, and an outer box side panel connected between the outer box top plate and the outer box bottom plate; Among the plurality of gas buffers (2), in the vacuum pumping mode, some of the gas buffers (2) are supported between the inner box bottom plate and the outer box bottom plate, and some of the gas buffers (2) are supported between the inner box side panels and the outer box side panels.

6. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The gas buffer (2) is an air bag, a receiving groove is provided on the top side of the air bag, and the bottom of the inner box (200) is fixed in the receiving groove; The airbag is provided with a plurality of connection ports, a plurality of buffer pipes (43) are provided, and each of the connection ports is connected to a buffer pipe (43).

7. The microphone signal-to-noise ratio test device according to claim 6, characterized in that: A limiting plate (3) is installed in the accommodating groove, the limiting plate (3) having a limiting groove opening toward the inner box (200), the limiting groove being adapted to the outer shape of the inner box (200), and the bottom of the inner box (200) being fixed in the limiting groove.

8. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The inflation and deflation mechanism (4) further comprises a buffer gas row (11), the buffer gas row (11) being provided with a first buffer gas port and a plurality of second buffer gas ports, the second interface (412) of the air pump (41) being connected to the first buffer gas port, a plurality of buffer pipes (43) being provided, and each of the second buffer gas ports being connected to a buffer pipe (43).

9. The microphone signal-to-noise ratio test device according to claim 2, characterized in that: The inflation and deflation mechanism (4) further comprises a base (44), the base (44) having a receiving cavity, the air pump (41), the cavity partition pipe (42) and the buffer pipe (43) being installed in the receiving cavity, and the outer box (100) being placed on the top surface of the base (44).

10. A microphone signal-to-noise ratio test system, characterized in that: It comprises a testing instrument and a microphone signal-to-noise ratio testing device according to any one of claims 1 to 9, wherein the testing instrument is used to test the signal-to-noise ratio of a microphone installed in the inner box (200).

Images