Acoustic detection device

Abstract

The embodiment of the utility model discloses an acoustic detection device. The acoustic detection device comprises an impedance tube, a sound production module and an acoustic module. The two opposite ends of the impedance tube along the axis are provided with a first opening and a second opening respectively, the sound production module is arranged at the first opening, and the acoustic module is detachably arranged at the second opening. The sound production module is provided with a first sound source and a first sound absorption material. When the acoustic detection device carries out detection, the first sound source sounds towards the acoustic module, and the acoustic module carries out feedback according to a specific detection item. According to the acoustic detection device provided by the embodiment of the utility model, through the structural arrangement, the acoustic detection device capable of carrying out different acoustic measurements on various products to be detected is provided, and the detection difficulty and the detection cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of acoustics, in particular to an acoustic detection device. Background Art

[0002] Acoustic testing is a non-contact measurement technology that obtains information about the properties, structure or other characteristics of the object to be tested by emitting sound wave signals and analyzing the reflected sound waves or calculating the sound waves received by the object to be tested. This method can be applied to many fields, including engineering, medicine, environmental science, etc. Depending on the nature of the object to be tested and the items to be tested, the acoustic testing of different objects to be tested often has different requirements, requiring the construction of different test scenes and the setting of different test instruments, making it difficult to easily measure different acoustic parameters of multiple objects to be tested. Utility Model Content

[0003] In view of this, an object of the present invention is to provide an acoustic detection device suitable for measuring different acoustic parameters of a variety of objects to be tested.

[0004] An embodiment of the present invention provides an acoustic detection device, which includes: an impedance tube having a tube wall, at least one through hole being arranged on the tube wall, the impedance tube having a first opening and a second opening at two ends opposite to each other along the axis; a sound module being arranged at the first opening, the sound module having a first sound source and a first sound-absorbing material, the first sound source facing the inside of the impedance tube; and an acoustic module being detachably connected to the second opening.

[0005] Furthermore, the acoustic module includes a hard boundary structure, which is arranged at the second opening and closes the second opening.

[0006] Furthermore, the acoustic detection device also includes at least one signal receiving component, the shape of the through hole matches the shape of the signal receiving component, and the signal receiving component passes through the through hole and extends into the impedance tube.

[0007] Furthermore, the signal receiving component includes two signal detection devices, the impedance tube has a plurality of through holes, the distances from the plurality of through holes to the first opening are all different, and the two signal receiving components are respectively arranged in different through holes.

[0008] Furthermore, the signal receiving component is arranged between the sound module and the acoustic module.

[0009] Furthermore, the acoustic module is used to accommodate the material to be detected.

[0010] Furthermore, the inner diameter of the impedance tube is 10 cm.

[0011] Furthermore, the acoustic module has a second sound source, and the first sound source and the second sound source are arranged oppositely at two ends of the impedance tube.

[0012] Furthermore, the through hole matches the shape of the microphone to be detected, and the microphone to be detected extends into the impedance tube through the through hole.

[0013] Further, a distance from at least one through hole to the first sound source is equal to a distance from at least one through hole to the second sound source.

[0014] Furthermore, the acoustic detection device also includes a control circuit, and the first sound source and the second sound source are electrically connected to the control circuit respectively. When the control circuit drives the first sound source to emit a first sound signal, the control circuit drives the second sound source to emit a second sound signal; when the control circuit drives the second sound source to emit a third sound signal, the control circuit drives the first sound source to emit a fourth sound signal.

[0015] Furthermore, the control circuit includes a signal delay device, which is a first filter or a delay component.

[0016] Furthermore, the first sound signal and the second sound signal are superimposed to form a first reference sound signal, and the third sound signal and the fourth sound signal are superimposed to form a second reference sound signal; the acoustic detection device also includes a reference signal receiving component electrically connected to the control circuit, the reference signal receiving component collects the first reference sound signal and the second reference sound signal, and the control circuit adjusts the time of driving the second sound source to emit the second sound signal or adjusts the time of driving the first sound source to emit the fourth sound signal according to the first reference sound signal and the second reference sound signal.

[0017] Furthermore, the control circuit also includes a second filter, and the second filter is a minimum mean square filter.

[0018] Furthermore, the acoustic module also includes a second sound absorbing material arranged on a side of the second sound source away from the sound emitting module.

[0019] Furthermore, the first sound absorbing material wraps an end of the first sound source away from the acoustic module.

[0020] The embodiment of the utility model discloses an acoustic detection device, which includes an impedance tube, a sound module and an acoustic module. The impedance tube has a first opening and a second opening at two opposite ends along the axis, the sound module is arranged at the first opening, and the acoustic module is detachably arranged at the second opening. The sound module has a first sound source and a first sound-absorbing material. When the acoustic detection device performs detection, the first sound source emits sound in the direction of the acoustic module, and the acoustic module provides feedback according to the specific detection items. Through the above-mentioned structural arrangement, the embodiment of the utility model provides an acoustic detection device that can perform different acoustic measurements on a variety of products to be tested, thereby reducing the detection difficulty and detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other purposes, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0022] Figure 1 It is a three-dimensional structural schematic diagram of an acoustic parameter measurement device provided by an embodiment of the utility model;

[0023] Figure 2 is a cross-sectional view of an acoustic detection device provided by an embodiment of the utility model;

[0024] Figure 3 It is a sound absorption coefficient curve diagram of an acoustic detection device provided by an embodiment of the utility model;

[0025] Figure 4 It is a sound field distribution diagram of an acoustic detection device provided by an embodiment of the utility model;

[0026] Figure 5 It is a schematic diagram of the three-dimensional structure of another acoustic detection device provided by an embodiment of the utility model;

[0027] Figure 6 is a cross-sectional view of another acoustic detection device provided by an embodiment of the utility model;

[0028] Figure 7 It is a circuit diagram of another acoustic detection device provided by an embodiment of the utility model;

[0029] Figure 8 This is a frequency response curve diagram measured by another acoustic detection device provided in an embodiment of the utility model.

[0030] Description of reference numerals:

[0031] 1-impedance tube; 11-tube wall; 111-through hole; 12-first opening; 13-second opening;

[0032] 2-sound module; 21-first sound source; 22-first sound absorbing material;

[0033] 3-acoustic module; 31-second sound source; 32-second sound absorbing material; 33-hard boundary structure;

[0034] 4-Detection signal receiving component;

[0035] 51- material to be tested; 52- microphone to be tested;

[0036] 6-reference signal receiving component; 61-first reference sound signal receiving component; 62-second reference sound signal receiving component;

[0037] 7-control circuit; 71-signal delay device; 72-second filter. DETAILED DESCRIPTION

[0038] The present application is described below based on embodiments, but the present application is not limited to these embodiments. In the detailed description of the present application below, some specific details are described in detail. It is possible for those skilled in the art to fully understand the present application without the description of these details. In order to avoid confusing the essence of the present application, known methods, processes, flows, components and circuits are not described in detail.

[0039] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0040] Unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] For ease of explanation, spatially relative terms such as "inside", "outside", "below", "below", "lower", "above", "upper", etc. are used herein to describe the relationship of one element or feature illustrated in the figures to another element or feature. It will be understood that spatially relative terms may be intended to include different orientations of the device in use or operation other than the orientation depicted in the figures. For example, if the device in the figure is turned over, the elements described as being "below" or "below" other elements or features will then be positioned as being "above" the other elements or features. Thus, the example term "below" can include both the orientations of above and below. The device may be oriented in other ways, and the spatially relative descriptors used herein should be interpreted accordingly.

[0042] Unless the context clearly requires otherwise, the words "include", "including" and similar words throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0043] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0044] The utility model provides an acoustic detection device, such as Figure 1and Figure 5 As shown, the acoustic detection device includes an impedance tube 1, a sound module 2 and an acoustic module 3. The product to be tested (such as a material to be tested 51 or a microphone to be tested 52) is arranged in the impedance tube 1, and the impedance tube 1 has a first opening 12 and a second opening 13 at two opposite ends along the axis, and the sound module 2 is arranged at the first opening 12, and the sound module 2 has a first sound source 21.

[0045] The impedance tube 1 is formed by wrapping the tube wall 11, and the inner wall of the impedance tube 1 has a smooth surface to prevent the viscous damping of the inner wall from attenuating the sound wave, thereby reducing the test error. The impedance tube 1 is a tubular structure with a circular cross section. The cross section of the tubular structure can also be a hollow rectangle, a hollow ellipse, etc. The outer shape and the inner shape of the cross section can be the same or different, for example, a structure with a rectangular outer side and a circular inner side. The specific cross-sectional shape is determined according to actual needs. When the acoustic detection device is used to perform acoustic numerical detection on the material to be detected 51, in order to further improve the test effect, the diameter of the impedance tube 1 can be limited to affect the transmission mode and transmission speed of the sound wave in the impedance tube 1. It can be seen from the simulation test that when the inner diameter of the impedance tube 1 is 10cm, the waveform in the impedance tube 1 is a plane wave. When the acoustic detection device is used to detect the microphone 52 to be detected, in order to simulate a soundless environment, setting the impedance tube 1 to have a larger aspect ratio can provide sufficient area for the relatively propagated cancellation sound and the detection sound during detection to be superimposed and offset. For example, the inner diameter is 6cm and the length is 50cm.

[0046] The structure of the acoustic module 3 is set according to the product to be tested. Specifically, when the acoustic detection device is used to detect the acoustic impedance and other values ​​of the material to be tested 51, the acoustic detection device has the following features: Figure 2 The acoustic module 3 has a hard boundary structure 33. When the acoustic detection device is used to detect the directivity of the microphone 52 to be detected, the acoustic detection device has the following structure: Figure 6 In the structure shown, the acoustic module 3 has a second sound source 31 .

[0047] like Figure 2As shown, when the acoustic detection device is used to measure the acoustic impedance of the material to be detected 51, the acoustic module 3 is arranged at the second opening 13, the acoustic module 3 is used to accommodate the material to be detected 51, and the acoustic module 3 has a hard boundary structure 33. The hard boundary structure 33 is arranged at the second opening 13 and closes the second opening 13. The hard boundary structure 33 is a boundary with high reflection ability and almost no absorption of sound energy, that is, a hard boundary. When the sound wave encounters a hard boundary, almost all of the sound energy will be reflected back, and almost no sound energy will be absorbed or transmitted to the inside of the boundary. Optionally, the hard boundary structure 33 is a rigid structure. When the material to be detected 51 is detected, the first sound source 21 generates an initial sound signal, which passes through the material to be detected 51 and is reflected by the hard boundary structure 33 and passes through the material to be detected 51 again to form a detection sound signal, and the initial sound signal and the detection sound signal are superimposed to form a generalized standing wave. By measuring the generalized standing wave and calculating it, the sound absorption coefficient curve of the material can be obtained, and the relevant parameters of the material to be detected 51 can be obtained.

[0048] The measuring device also includes a detection signal receiving component 4, which is used to receive the initial sound signal and the detection sound signal. The tube wall 11 of the impedance tube 1 has at least one through hole 111, which penetrates the tube wall 11 and connects the inside and outside of the impedance tube 1. The through hole 111 is used to set the detection signal receiving component 4, so the shape of the through hole 111 matches the shape of the detection signal receiving component 4, and the detection signal receiving component 4 is set in the impedance tube 1 through the through hole 111. Figure 2 As shown, the tube wall 11 has a plurality of through holes 111, and the distances from the plurality of through holes 111 to the first opening 12 are all different. In this embodiment, the acoustic detection device includes two reference signal receiving components 6, and the two reference signal receiving components 6 are respectively arranged in different through holes 111. Optionally, the two reference signal receiving components 6 are arranged near the middle between the sound module 2 and the acoustic module 3.

[0049] When the material to be detected 51 is detected, the first sound source 21 generates an initial sound signal. After passing through the material to be detected 51, the initial sound signal is reflected by the hard boundary structure 33 and passes through the material to be detected 51 again to form a detection sound signal. The initial sound signal and the detection sound signal are superimposed to form a generalized standing wave. The sound field distribution diagram in the impedance tube 1 is shown in FIG. Figure 4 The two detection signal receiving components 4 respectively measure the amplitude and phase of the sound signal (including the initial sound signal and the detection sound signal) to obtain a frequency response curve, and then convert the response curve into a transfer function, and then calculate the transfer function of the two microphones to obtain the following: Figure 3 The sound absorption coefficient curve of the material to be detected 51 is shown. In some embodiments, the material to be detected 51 may be a porous material, and the sound absorption coefficient curve of the material to be detected 51 obtained by calculation is used to fit the parameters of the porous material.

[0050] In this embodiment, the sound module 2 further includes a first sound absorbing material 22 disposed on the side of the first sound source 21 away from the acoustic module 3. The first sound absorbing material 22 is used to absorb the detection sound signal propagating toward the first sound source 21, so as to prevent the detection sound signal from continuing to reflect from the sound module 2 and thus superimposing with the initial sound signal emitted by the first sound source 21. In this embodiment, the first sound absorbing material 22 may be a sound absorbing board, sound insulation cotton, or other material that can reduce sound reflection and absorb noise. Optionally, the first sound absorbing material 22 wraps the rear end of the first sound source 21 (the end opposite to the sound emitting end).

[0051] The sound module 2 and / or the acoustic module 3 are detachably connected to the impedance tube 1. In this embodiment, sealing rings are respectively provided at the connection between the sound module 2 and the impedance tube 1 and at the connection between the acoustic module 3 and the impedance tube 1, so as to ensure that the acoustic detection device does not leak sound during the measurement process and improve the reliability of the test.

[0052] When producing differential pressure microphones, it is necessary to test whether the differential pressure microphones are assembled correctly and whether there are any air leaks. During the test, the microphone to be tested (i.e. the newly produced differential pressure microphone) needs to be placed in an open, soundless environment, with the walls of the environment far enough away from the microphone to be tested. However, there is no such testing environment on the production line of differential pressure microphones, so it is impossible to quickly test, resulting in reduced production efficiency and product reliability of differential pressure microphones.

[0053] like Figure 6 As shown, the acoustic detection device is used to detect the assembly performance of the microphone 52 to be detected. The acoustic module 3 has a second sound source 31. When the microphone 52 to be detected needs to be detected, the first sound source 21 sends a first sound signal, and the first sound signal is offset by the second sound signal sent by the second sound source 31 after passing through the microphone 52 to be detected, that is, Figure 6 The first sound source 21 emits a first sound signal transmitted to the right, and the second sound source 31 emits a second sound signal transmitted to the left; the second sound source 31 emits a third sound signal, and the third sound signal is offset by the fourth sound signal emitted by the first sound source 21 after passing through the microphone 52 to be detected, that is, Figure 6 The second sound source 31 emits a third sound signal transmitted to the left, and the first sound source 21 emits a fourth sound signal transmitted to the right. At this time, the microphone 52 to be detected is approximately in an empty and soundless environment, and the detection signal reflected by the side wall of the environment will not be reflected to the microphone 52 to be detected.

[0054] The acoustic detection device also includes a control circuit 7, and the first sound source 21 and the second sound source 31 are electrically connected to the control circuit 7 respectively. When the first sound source 21 is used to detect the microphone 52 to be detected, the control circuit 7 sends a first detection signal to the first sound source 21 so that the first sound source 21 sends a first sound signal, and sends a first cancellation signal to the second sound source 31 so that the second sound source 31 sends a second sound signal. When the second sound source 31 is used to detect the microphone 52 to be detected, the control circuit 7 sends a second detection signal to the second sound source 31 so that the second sound source 31 sends a third sound signal, and sends a second cancellation signal to the first sound source 21 so that the first sound source 21 sends a fourth sound signal. Among them, the first sound signal and the third sound signal are both swept frequency signals, and the frequency scanning speed of the swept frequency signal can be set according to the microphone 52 to be detected. The second sound signal is a sound signal with the same amplitude and opposite phase as the first sound signal, and the fourth sound signal is a sound signal with the same amplitude and opposite phase as the third sound signal. By controlling the time difference between the second sound signal and the first sound signal, and between the fourth sound signal and the third sound signal, interference may occur between the two groups of sound signals, thereby canceling each other out.

[0055] In order to enable the control circuit 7 to accurately cancel the signals sent to the first sound source 21 and the second sound source 31 after passing through the microphone 52 to be detected, the control circuit 7 includes a signal delay device 71. The signal delay device 71 can be a first filter or a delay component. Taking the acoustic detection device using the first sound source 21 to send a first sound signal as an example, the control circuit 7 sends the first detection signal to the first sound source 21, and the first sound source 21 receives the first detection signal and sends a first sound signal. The signal delay device 71 is used to delay the time when the first cancellation signal sent by the control circuit 7 reaches the second sound source 31, so that the second sound source 31 sends the second sound signal after the first sound source 21 sends the first sound signal, so that the propagation distance of the first sound signal is greater than the propagation distance of the second sound signal, and then the first sound signal meets and cancels the second sound signal after passing through the microphone 52 to be detected.

[0056] However, due to the loss of the sound signal during the propagation process, the physical delay of the first sound signal or the third sound signal caused by the length of the impedance tube 1, and the delay value of the signal delay device 71 needs to be debugged, so the second sound signal and the first sound signal, the fourth sound signal and the third sound signal cannot completely cancel each other out, but some sound signals will remain. Specifically, the residual noise signal formed by the superposition of the first sound signal and the second sound signal can be called the first reference sound signal, and the residual noise signal formed by the superposition of the third sound signal and the fourth sound signal can be called the second reference sound signal. In order to reduce the residual noise signal, the acoustic detection device also includes a reference signal receiving component 6 electrically connected to the control circuit 7, and the reference signal receiving component 6 collects the first reference sound signal and the second reference sound signal. The control circuit 7 adjusts the first cancellation signal according to the first reference sound signal, and adjusts the second cancellation signal according to the second reference sound signal.

[0057] In this embodiment, the reference signal receiving component 6 includes a first reference sound signal receiving component 61 and a second reference sound signal receiving component 62. The first reference sound signal receiving component 61 is disposed near the sound module 2 and receives the second reference sound signal, and the second reference sound signal receiving component 62 is disposed near the acoustic module 3 and receives the first reference sound signal. Figure 7As shown, the control circuit 7 also includes a second filter 72, the first reference sound signal receiving component 61 feeds back the received second reference sound signal to the second filter 72, the second reference sound signal receiving component 62 feeds back the received first reference sound signal to the second filter 72, and the second filter 72 adjusts the signal delay device 71 according to the reference signal (the first reference sound signal or the second reference sound signal), so that when the signal delay device 71 sends the second cancellation signal to the first sound source 21 and sends the first cancellation signal to the second sound source 31, the delay time is more accurate. The second filter 72 is an adaptive filter, which can automatically adjust the filter parameters according to the characteristics of the input signal. In this embodiment, the second filter 72 is a minimum mean square filter (Least Mean Square Filter, LMS Filter), which uses the minimum mean square (Least Mean Square, LMS) algorithm to continuously adjust the filter weights to minimize the mean square error between the output signal and the expected output signal. In some embodiments, the second filter 72 may also be selected from recursive least squares filter (RLS filter), minimum mean square error filter (RLS filter), infinite impulse response adaptive filter (IIR filter), etc. The second filter 72 corrects the delay value of the delay component to the first cancellation signal according to the received first reference sound signal. The second filter 72 also corrects the delay value of the delay component to the second cancellation signal according to the received second reference sound signal, so that the cancellation between the second sound signal and the first sound signal, and the fourth sound signal and the third sound signal is optimized, so that the microphone 52 to be tested is located in a test environment that is equivalent to an anechoic environment but occupies a smaller area.

[0058] The through hole 111 on the impedance tube 1 includes a test hole for setting the microphone 52 to be detected and a reference hole for setting the reference signal receiving component 6. In order to ensure the structural strength of the tube wall 11 where the through hole 111 is opened, and to provide certain support for the reference signal receiving component 6 and the microphone 52 to be detected, the thickness of the tube wall 11 where the through hole 111 is set is greater than the thickness of the tube wall 11 in other areas. In this embodiment, the distance from the first sound source 21 to the test hole is substantially equal to the distance from the second sound source 31 to the test hole, so that the distance from the microphone 52 to be detected set in the impedance tube 1 through the test hole to the first sound source 21 and the second sound source 31 is approximately equal, so that the reference signal receiving component 6 set in the center of the impedance tube 1 is less interfered by near-field sound waves, which can improve the accuracy of the test. At least two reference holes are respectively set close to the first sound source 21 and the second sound source 31, so that in the two reference signal receiving components 6, the first reference sound signal receiving component 61 is set close to the first sound source 21, and the second reference sound signal receiving component 62 is set close to the second sound source 31. In this embodiment, the reference hole and the test hole have the same size, so only one row of through holes 111 with equal apertures need to be provided on the tube wall 11. The spacing between adjacent through holes 111 can be equal or unequal.

[0059] In this embodiment, sealing rings are respectively provided at the connection between the sound module 2 and the impedance tube 1 and at the connection between the acoustic module 3 and the impedance tube 1, so as to ensure that the acoustic detection device does not leak sound during the measurement process and improve the reliability of the test.

[0060] In this embodiment, the sound module 2 further includes a first sound absorbing material 22 disposed on the side of the first sound source 21 away from the second sound source 31; the acoustic module 3 further includes a second sound absorbing material 32 disposed on the side of the second sound source 31 away from the first sound source 21. The first sound absorbing material 22 is used to absorb the third sound signal emitted by the second sound source 31 but not offset by the fourth sound signal, and the second sound absorbing material 32 is used to absorb the first sound signal emitted by the first sound source 21 but not offset by the second sound signal, further ensuring that there is no residual noise signal propagating to the microphone 52 to be detected. The first sound absorbing material 22 and the second sound absorbing material 32 can be materials such as sound absorbing panels and sound insulation cotton that can reduce sound reflection and absorb noise. In this embodiment, the first sound absorbing material 22 wraps the rear end (the end opposite to the sound emitting end) of the first sound source 21, and the second sound absorbing material 32 wraps the rear end (the end opposite to the sound emitting end) of the second sound source 31.

[0061] When the acoustic detection device provided by the embodiment of the utility model is used for testing, the microphone 52 to be detected is first set in the impedance tube 1 through the through hole 111. When the control circuit 7 sends the first detection signal to the first sound source 21 and sends the first cancellation signal to the second sound source 31, the signal delay device is configured to delay the output of the first cancellation signal, and the second filter 72 is configured to correct the first cancellation signal. The first sound signal is a propagating wave transmitted from the first sound source 21 to the second sound source 31, and the microphone 52 to be detected receives the first sound signal. When the control circuit 7 sends the second detection signal to the second sound source 31 and sends the second cancellation signal to the first sound source 21, the signal delay device is configured to delay the output of the second cancellation signal, and the second filter 72 is configured to correct the second cancellation signal. The third sound signal is a propagating wave transmitted from the second sound source 31 to the first sound source 21, and the microphone 52 to be detected receives the third sound signal. The first sound signal and the third sound signal with opposite transmission directions can respectively simulate the sound waves transmitted along the front and rear of the microphone 52 to be detected. Figure 8 This is a frequency response curve diagram measured by another acoustic detection device provided by an embodiment of the utility model. The two curves in the figure represent the indication effect of the microphone 52 to be detected on the sound waves coming from the front and the back respectively. The greater the difference between the two curves, the better the directivity of the microphone 52 to be detected, indicating that the assembly of the microphone 52 to be detected does not leak sound. When the microphone 52 to be detected has the problem of sound leakage, the difference between the two lines in the frequency response curve diagram decreases.

[0062] The acoustic detection device includes an impedance tube 1 and a sound module 2 and an acoustic module 3 arranged on opposite sides of the impedance tube 1. The sound module 2 is fixedly connected or detachably connected to the impedance tube 1, and the acoustic module 3 is detachably connected to the impedance tube 1, so that the measurement items of the acoustic detection device can be changed by replacing the structure connecting the two ends of the impedance tube 1. Figure 1 and Figure 2 The sound module 2 of the acoustic detection device shown is similar to Figure 5 and Figure 6 The structure of the sound module 2 of the acoustic detection device shown can be completely the same; Figure 1 and Figure 2 The sound module 2 of the acoustic detection device shown is similar to Figure 5 and Figure 6The structure of the impedance tube 1 of the acoustic detection device shown can be completely the same, so that the measurement items of the acoustic detection device can be changed by replacing the structure connected at both ends of the impedance tube 1. For example, the first opening 12 of the impedance tube 1 is connected to the sound module 2, and the second opening 13 of the impedance tube 1 is connected to the acoustic module 3 with the second sound source 31. At this time, the structure formed is an acoustic detection device for detecting the microphone 52 to be detected. The first opening 12 of the impedance tube 1 is connected to the sound module 2, and the second opening 13 is connected to the acoustic module 3 with the hard boundary structure 33. At this time, the structure formed is an acoustic detection device for detecting the material 51 to be detected.

[0063] The embodiment of the utility model discloses an acoustic detection device. An impedance tube and a sound module disposed at the first opening of the impedance tube can reuse different acoustic detection devices. Different measuring devices can be formed by replacing the acoustic module connected to the second opening of the impedance tube. Specifically, an acoustic module having a second sound source is disposed at the second opening to constitute an acoustic detection device that can measure a microphone to be detected, and an acoustic module having a hard boundary structure is disposed at the second opening to constitute an acoustic detection device that can detect a material to be detected. The utility model provides a structure having an impedance tube and a sound module, so that different acoustic measurements can be performed on a variety of products to be tested after replacing different acoustic modules, thereby reducing the difficulty and cost of detection.

[0064] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An acoustic detection device, characterized in that: The acoustic detection device comprises: An impedance tube (1) comprises a tube wall (11), at least one through hole (111) is arranged on the tube wall (11), and the impedance tube (1) has a first opening (12) and a second opening (13) at two opposite ends along the axis respectively; A sound-generating module (2) is arranged at the first opening (12), the sound-generating module (2) having a first sound source (21) and a first sound-absorbing material (22), the first sound source (21) facing the interior of the impedance tube (1); The acoustic module (3) is detachably connected to the second opening (13).

2. The acoustic detection device according to claim 1, characterized in that: The acoustic module (3) comprises a hard boundary structure (33), wherein the hard boundary structure (33) is arranged at the second opening (13) and closes the second opening (13).

3. The acoustic detection device according to claim 2, characterized in that: The acoustic detection device further comprises at least one detection signal receiving component (4); the shape of the through hole (111) matches the shape of the detection signal receiving component (4); and the detection signal receiving component (4) passes through the through hole (111) and extends into the impedance tube (1).

4. The acoustic detection device according to claim 3, characterized in that: The detection signal receiving component (4) comprises two detection signal receiving components (4); the impedance tube (1) has a plurality of through holes (111); the distances between the plurality of through holes (111) and the first opening (12) are all different; and the two detection signal receiving components (4) are respectively arranged in different through holes (111).

5. The acoustic detection device according to claim 3 or 4, characterized in that: The detection signal receiving component (4) is arranged between the sound generating module (2) and the acoustic module (3).

6. The acoustic detection device according to claim 2, characterized in that: The acoustic module (3) is used to accommodate the material (51) to be detected.

7. The acoustic detection device according to claim 2, characterized in that: The inner diameter of the impedance tube (1) is 10 cm.

8. The acoustic detection device according to claim 1, characterized in that: The acoustic module (3) has a second sound source (31), and the first sound source (21) and the second sound source (31) are arranged opposite to each other at two ends of the impedance tube (1).

9. The acoustic detection device according to claim 8, characterized in that: The through hole (111) matches the shape of the microphone (52) to be detected, and the microphone (52) to be detected passes through the through hole (111) and extends into the impedance tube (1).

10. The acoustic detection device according to claim 8, characterized in that: The distance between at least one of the through holes (111) and the first sound source (21) is equal to the distance between at least one of the through holes (111) and the second sound source (31).

11. The acoustic detection device according to claim 8, characterized in that: The acoustic detection device further comprises a control circuit (7), wherein the first sound source (21) and the second sound source (31) are electrically connected to the control circuit (7) respectively; when the control circuit (7) drives the first sound source (21) to emit a first sound signal, the control circuit (7) drives the second sound source (31) to emit a second sound signal; and when the control circuit (7) drives the second sound source (31) to emit a third sound signal, the control circuit (7) drives the first sound source (21) to emit a fourth sound signal.

12. The acoustic detection device according to claim 11, characterized in that: The control circuit (7) comprises a signal delay device (71), and the signal delay device (71) is a first filter or a delay component.

13. The acoustic detection device according to claim 11 or 12, characterized in that: The first sound signal and the second sound signal are superimposed to form a first reference sound signal, and the third sound signal and the fourth sound signal are superimposed to form a second reference sound signal; The acoustic detection device further comprises a reference signal receiving component (6) electrically connected to the control circuit (7), wherein the reference signal receiving component (6) collects a first reference sound signal and a second reference sound signal, and the control circuit (7) adjusts the time for driving the second sound source (31) to emit a second sound signal or adjusts the time for driving the first sound source (21) to emit a fourth sound signal according to the first reference sound signal and the second reference sound signal.

14. The acoustic detection device according to claim 13, characterized in that: The control circuit (7) further comprises a second filter (72), wherein the second filter (72) is a minimum mean square filter.

15. The acoustic detection device according to claim 8, characterized in that: The acoustic module (3) further comprises a second sound absorbing material (32) arranged on a side of the second sound source (31) away from the sound generating module (2).

16. The acoustic detection device according to claim 8, characterized in that: The impedance tube (1) has an inner diameter of 6 cm and a length of 50 cm.

17. The acoustic detection device according to claim 2 or 8, characterized in that: The first sound absorbing material (22) wraps an end of the first sound source (21) away from the acoustic module (3).

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