Sound absorption module and sound absorption structure

Abstract

The utility model provides a sound absorption module and a sound absorption structure. The sound absorption module comprises a first sound absorption structure which is provided with at least one first sound absorption unit, and the first sound absorption unit is provided with an open hole and an insertion pipe extending from the open hole to an inner cavity of the first sound absorption unit; the second sound absorption structure is provided with at least one second sound absorption unit; the first sound absorption structure and the second sound absorption structure are arranged in the same face. Moreover, the first sound absorption structure is configured to absorb sound waves of a first frequency band, the second sound absorption structure is configured to absorb sound waves of a second frequency band, the lower limit value of the first frequency band is smaller than the lower limit value of the second frequency band, and the upper limit value of the first frequency band is smaller than the upper limit value of the second frequency band. According to the sound absorption module, the thickness and the preparation cost can be obviously reduced on the premise of ensuring the sound absorption bandwidth.

Description

Technical Field

[0001] The utility model relates to the technical field of sound absorption, in particular to a sound absorption module and a sound absorption structure. Background Art

[0002] With the advancement of technology, people are increasingly demanding the acoustic performance of high-tech products and quieter homes. Traditional porous materials already possess excellent sound absorption properties. By incorporating low-frequency meta-structured sound-absorbing materials, even stronger noise shielding or directional sound wave absorption can be achieved. This combination has important applications in traffic noise control and building noise barriers.

[0003] While the combination of porous materials and metastructured sound absorbers holds enormous potential for application, it also faces several technical challenges. For example, the structural design of porous structures and metastructured sound absorbers typically requires precise geometric control. Furthermore, further research is needed to optimize the design of metastructured sound absorbers to achieve the desired performance improvements without compromising the inherent functionality of the porous materials. Utility Model Content

[0004] Based on this, the present invention aims to provide an improved sound absorbing module and sound absorbing structure to solve at least one of the above problems.

[0005] In a first aspect, the present application provides a sound absorption module, comprising:

[0006] a first sound absorbing structure having at least one first sound absorbing unit, wherein the first sound absorbing unit has an opening and an insertion tube extending from the opening to an inner cavity of the first sound absorbing unit; and

[0007] a second sound absorbing structure having at least one second sound absorbing unit;

[0008] Wherein, the first sound absorbing structure and the second sound absorbing structure are arranged in the same plane;

[0009] Furthermore, the first sound absorbing structure is configured to absorb sound waves in a first frequency band, and the second sound absorbing structure is configured to absorb sound waves in a second frequency band, wherein a lower limit value of the first frequency band is smaller than a lower limit value of the second frequency band, and an upper limit value of the first frequency band is smaller than an upper limit value of the second frequency band.

[0010] The above-mentioned sound absorption module has at least the following beneficial effects:

[0011] 1. By arranging the first sound absorbing structure and the second sound absorbing structure in the same plane, the overall structure has only one layer, which is conducive to significantly reducing the thickness of the sound absorbing module;

[0012] 2. Under the same web size, the first sound absorbing structure and the second sound absorbing structure can share the web size, so that the sound absorbing module requires less materials to prepare, which is conducive to reducing the preparation cost;

[0013] 3. The structure of the opening and the inserted tube can make the first sound absorption unit have a resonant cavity structure to achieve resonant sound absorption. Therefore, the combination of the first sound absorption structure and the second sound absorption structure with a higher sound absorption frequency can ensure the sound absorption bandwidth of the sound absorption module. In addition, the sound absorption frequency can be adjusted by changing the parameters of the opening and the inserted tube. After combination, it can achieve absorption of any target noise frequency band.

[0014] 4. The resonant cavity type sound absorbing unit can unify the size and reduce the structural complexity of the sound absorbing unit, which is conducive to reducing the difficulty of preparation and further reducing the preparation cost.

[0015] In one embodiment, the upper limit value of the first frequency band is less than or equal to the lower limit value of the second frequency band.

[0016] In one embodiment, the first sound absorbing structure and the second sound absorbing structure are arranged side by side.

[0017] In one embodiment, the first sound absorbing structure has a plurality of first sound absorbing unit groups, each of which is arranged side by side in sequence along a first direction, and each of the first sound absorbing units in each of the first sound absorbing unit groups is arranged in a second direction in which the sound absorption frequency increases or decreases in sequence, and the second direction is different from the first direction.

[0018] In one embodiment, the second sound absorbing unit comprises a porous sound absorbing material, and each of the porous sound absorbing materials is located on one side of the first sound absorbing structure and is arranged side by side with the first sound absorbing structure.

[0019] In one embodiment, each of the first sound absorbing units and each of the second sound absorbing units are randomly arranged side by side.

[0020] In one embodiment, at least two of the first sound absorbing units are adjacent to each other and spaced apart, and at least one of the second sound absorbing units is located between the two adjacent first sound absorbing units.

[0021] In one embodiment, the second sound absorbing unit includes a porous sound absorbing material and a bottom plate located on a side of the porous sound absorbing material away from the opening of the first sound absorbing unit.

[0022] In one embodiment, the first frequency band includes 500 Hz to 1200 Hz, and the second frequency band includes 1200 Hz to 10000 Hz.

[0023] In one embodiment, the radius of the opening is in the range of 1.6 mm to 3.5 mm, and the length of the insertion tube is in the range of 2 mm to 4 mm.

[0024] In one embodiment, the thickness of the sound absorbing module ranges from 4 mm to 20 mm.

[0025] In a second aspect, the present application provides a sound-absorbing structure comprising a plurality of sound-absorbing modules as described in any of the foregoing embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the implementation methods of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 This is a structural diagram of a sound absorption module 10 according to an embodiment of the present application;

[0028] Figure 2 1 is a schematic top view of a sound absorbing module 10 according to an embodiment of the present application;

[0029] Figure 3 for Figure 2 A schematic cross-sectional view of the AA plane of the illustrated embodiment;

[0030] Figure 4 for Figure 2 A schematic cross-sectional view of the BB surface of the illustrated embodiment;

[0031] Figure 5 Schematic top view of a sound absorbing module 20 according to an embodiment of the present application;

[0032] Figure 6 for Figure 5 A schematic cross-sectional view of the CC plane of the illustrated embodiment;

[0033] Figure 7 This is a structural diagram of the sound absorbing module 20 according to an embodiment of the present application without the porous sound absorbing material;

[0034] Figure 8 This is a schematic diagram of the sound absorption effect of the first specific embodiment of the present application;

[0035] Figure 9 This is a schematic diagram of the sound absorption effect of the second specific embodiment of the present application;

[0036] Figure 10Schematic diagram comparing the sound absorption effects of the first and second specific embodiments of the present application.

[0037] Component number description:

[0038] 10. Sound absorption module, 20. Sound absorption module;

[0039] 110, first sound absorbing structure, 111, first sound absorbing unit, 111A, first sound absorbing unit group, 111B, first sound absorbing unit group, 1111, opening, 1112, insertion tube, 1113, inner cavity, 120, second sound absorbing structure, 121, second sound absorbing unit;

[0040] 210. First sound absorbing structure, 211. First sound absorbing unit, 2111. Opening, 2112. Insertion tube, 2113. Inner cavity, 2114. Hard wall, 220. Second sound absorbing structure, 221. Second sound absorbing unit, 2211. Porous sound absorbing material, 2212. Bottom plate. DETAILED DESCRIPTION

[0041] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0045] Traditional materials such as glass fiber, foam board, rock wool and micro-perforated panels are commonly used for sound absorption in buildings. However, the sound absorption effect of porous sound-absorbing materials is mainly concentrated in the medium and high frequency bands, and the sound absorption effect in the low frequency band is poor. In order to ensure a certain sound absorption bandwidth (mainly to cover low frequencies), the thickness of the porous sound-absorbing materials needs to be large, resulting in a reduction in the indoor movable space in the building. Although micro-perforated panels can achieve better sound absorption effects in the low frequency bands through the design of unit structures, they are limited by the number of units and the width of the structure itself. Their sound absorption bandwidth and sound absorption effect in the medium and high frequency bands are usually not as good as porous sound-absorbing materials.

[0046] In response to the above-mentioned problems, the embodiments of the present application provide a sound absorption module that can ensure a wide sound absorption bandwidth, a small thickness, and a low cost. Specifically, by arranging the first sound absorption structure and the second sound absorption structure in the same plane, the overall structure has only one layer, which is conducive to significantly reducing the thickness of the sound absorption module. At the same time, under the same web size, the first sound absorption structure and the second sound absorption structure in the sound absorption module of the present application can share the web structure, so that less preparation materials are required, which is conducive to reducing preparation costs. In addition, the sound absorption module of the present application can enable the first sound absorption unit to have a resonant cavity structure through the structure of the opening and the insertion tube to achieve resonant sound absorption. Therefore, the combination of the first sound absorption structure and the second sound absorption structure with a higher sound absorption frequency can ensure the sound absorption bandwidth of the sound absorption module. In addition, by changing the parameters of the opening and the insertion tube, the sound absorption frequency can be adjusted. After the combination, it can achieve absorption of any target noise frequency band. In addition, the resonant cavity sound absorption unit can be unified in size, reducing the structural complexity of the sound absorption unit, which is conducive to reducing the difficulty of preparation and further reducing the preparation cost.

[0047] like Figures 1 to 4As shown, an embodiment of the present application provides a sound absorbing module 10, comprising: a first sound absorbing structure 110 having at least one first sound absorbing unit 111, the first sound absorbing unit 111 having an opening 1111 and an insertion tube 1112 extending from the opening 1111 into an inner cavity 1113 of the first sound absorbing unit 111; and a second sound absorbing structure 120 having at least one second sound absorbing unit 121. The first sound absorbing structure 110 and the second sound absorbing structure 120 are disposed in the same plane. Furthermore, the first sound absorbing structure 110 is configured to absorb sound waves in a first frequency band, and the second sound absorbing structure 120 is configured to absorb sound waves in a second frequency band. The lower limit of the first frequency band is smaller than the lower limit of the second frequency band, and the upper limit of the first frequency band is smaller than the upper limit of the second frequency band.

[0048] For example, the first sound absorption unit 111 can be a Fabry-Perot resonator or a Helmholtz resonator, and the corresponding resonant cavity is a Fabry-Perot resonator or a Helmholtz resonator. By accurately describing the loss of sound waves in different resonant cavities and utilizing impedance matching control of multiple resonant cavities with different structures, broadband sound absorption can be achieved. Optionally, by adjusting the radius of the opening 1111 and the length of the insertion tube 1112, the acoustic impedance of the first sound absorption unit 111 can be effectively controlled, thereby achieving impedance matching.

[0049] Optionally, the material of the first sound absorbing unit 111 includes one or more of polymer materials, metal materials, glass and ceramics. Optionally, the first sound absorbing unit 111 can be processed and formed by 3D printing, injection molding, molding, extrusion, die casting or casting.

[0050] Exemplarily, the second sound absorbing unit 121 includes a porous sound absorbing material, and the porous sound absorbing material is made of a fiber material, such as a fibrous porous sound absorbing material (such as glass wool, mineral wool), a foam porous sound absorbing material (such as polyurethane foam, phenolic foam), etc.

[0051] For example, when the first frequency range is A1-B1 and the second frequency range is A1-B2, A1 < A2 and B1 < B2. Optionally, the upper limit of the first frequency range is less than the lower limit of the second frequency range, i.e., B1 ≤ A2. This helps further broaden the sound absorption frequency range of the sound absorption module.

[0052] For example, the arrangement surface of the first sound absorbing structure 110 and the second sound absorbing structure 120 may be a flat surface or a curved surface.

[0053] In some embodiments of the present application, Figure 1 and Figure 2As shown, the first sound absorbing structure 110 and the second sound absorbing structure 120 are arranged side by side. Optionally, "side by side" can mean that the side edge of the first sound absorbing structure 110 is in contact with the side edge of the second sound absorbing structure 120. However, it should be noted that the stacking of the first sound absorbing structure 110 and the second sound absorbing structure 120 does not constitute "side by side".

[0054] Optional, see Figure 2 The first sound absorbing structure 110 comprises a plurality of first sound absorbing unit groups 111A, 111B, etc., arranged side by side in a first direction D1. The first sound absorbing units within each first sound absorbing unit group are arranged along a second direction D2 with increasing or decreasing sound absorption frequencies. The second direction D2 is different from the first direction D1. Optionally, the second direction D2 is perpendicular to the first direction D1. This simplifies the structure of the sound absorbing module 10 and facilitates the fabrication of the first sound absorbing structure 110.

[0055] Optionally, to simplify the preparation, each first sound absorbing unit may share the same front panel and the same back panel, and openings and insertion tubes may be provided on the same front panel to correspond to the internal cavities, respectively, to form a plurality of first sound absorbing units 111 .

[0056] Optional, such as Figure 2 and Figure 4 As shown, the second sound absorbing unit 121 includes porous sound absorbing materials, each of which is located on one side of the first sound absorbing structure 110 and arranged side by side with the first sound absorbing structure 110. Figure 4 As shown, the porous sound-absorbing material can be a single piece or composed of multiple smaller pieces, depending on the actual design requirements. In this case, the porous sound-absorbing material is free of obstructions, i.e., it is not protected by rigid walls. Therefore, the sound absorption bandwidth of the porous sound-absorbing material and the first sound-absorbing structure 110 is more smoothly connected.

[0057] In some embodiments of the present application, Figure 5 and Figure 6 As shown, the first sound absorbing units 211 and the second sound absorbing units 221 in the sound absorbing module 20 are randomly arranged side by side. For example, "randomly arranged side by side" means that the first sound absorbing units 211 and the second sound absorbing units 221 are randomly arranged on the same surface, and the side walls of adjacent sound absorbing units are arranged in contact with each other.

[0058] Optionally, at least two first sound absorbing units 211 are adjacent and spaced apart, and at least one second sound absorbing unit 221 is located between the two adjacent first sound absorbing units 211. Optionally, the second sound absorbing unit 221 includes a porous sound absorbing material 2211 and a bottom plate 2212 located on a side of the porous sound absorbing material 2211 away from the openings of the first sound absorbing unit 211. Optionally, the porous sound absorbing material 2211 located at the edge is further provided with a side plate 2213 for limiting and fixing it. Figure 7 As shown, the porous sound-absorbing material 2211 is protected by the hard wall 2114, so that the sound absorption effect at the junction of the frequency bands is closer to that of the first sound-absorbing structure 210. Therefore, a clear valley will appear at the junction. However, in the high-frequency band, the hard wall around the porous sound-absorbing material 2211 can enhance its sound absorption effect to some extent.

[0059] Optionally, the bottom plate of the first sound absorbing unit 211 and the bottom plate of the second sound absorbing unit 221 can be integrally formed to simplify the manufacturing process and enhance the structural integrity of the sound absorbing module 20. Optionally, the side panels 2213 of the second sound absorbing unit 221 can also be integrally formed with the side panels of the first sound absorbing unit 211, which also helps simplify the manufacturing process and enhance the structural integrity of the sound absorbing module 20.

[0060] In some embodiments of the present application, the sound absorption frequency band of the sound absorption module 10 / 20 includes 500 Hz to 10,000 Hz, wherein the first frequency band includes 500 Hz to 1,200 Hz, and the second frequency band includes 1,200 Hz to 10,000 Hz.

[0061] Furthermore, the radius of the opening 1111 / 2111 ranges from 1.6mm to 3.5mm, for example, it can be one of 1.6mm, 1.9mm, 2.2mm, 2.5mm, 2.8mm, 3.1mm, and 3.5mm; the length of the insertion tube 1112 / 2112 ranges from 2mm to 4mm, for example, it can be one of 2mm, 2.5mm, 3mm, 3.5mm, and 4mm.

[0062] Furthermore, the thickness of the sound absorbing module 10 / 20 ranges from 4 mm to 20 mm, for example, it can be one of 4 mm, 7 mm, 10 mm, 13 mm, 16 mm, 19 mm, and 20 mm.

[0063] The sound absorption module of the present application will be further described below through two specific embodiments. Specific embodiment 1

[0065] like Figure 1As shown, the sound absorption module 10 has a thickness of 20 mm and a format size of 202 mm * 202 mm. One side is a Helmholtz resonator array (i.e., a first sound absorption structure 110) for absorbing low-frequency sound waves, and the other side is a porous sound absorption material (i.e., a second sound absorption structure 120, which can be, for example, a sponge). The cavity opening and insertion tube sizes of each Helmholtz resonator are different, and the Helmholtz resonators are arranged in order of the size of the sound absorption frequency point, so that the Helmholtz resonator array has a better sound absorption effect in the low-frequency band.

[0066] Among them, the radius of the opening 1111 ranges from 1.6mm to 3.5mm, for example, it can be one of 1.6mm, 1.9mm, 2.2mm, 2.5mm, 2.8mm, 3.1mm, and 3.5mm; the length of the insertion tube 1112 ranges from 2mm to 4mm, for example, it can be one of 2mm, 2.5mm, 3mm, 3.5mm, and 4mm.

[0067] Furthermore, the sound absorption module 10 was tested using a reverberation chamber, and the sound absorption effect was as follows: Figure 8 As shown, the sound absorption frequency range covers 500Hz to 10,000Hz. The Helmholtz resonator array's primary operating frequency range is 500Hz to 1200Hz, while the porous sound-absorbing material's subsequent frequency range of 1200Hz to 10,000Hz is also effective. As can be seen, the sound absorption module 10 exhibits excellent sound absorption performance in the 500Hz to 10,000Hz range. Specific embodiment 2

[0069] like Figure 5 As shown, this embodiment provides another arrangement of the Helmholtz resonator array and the porous sound-absorbing material (such as sponge). In this embodiment, the Helmholtz resonators are randomly arranged and the porous sound-absorbing material is placed in the cavity between two adjacent Helmholtz resonators. The thickness of the sound-absorbing module 20 is 20mm and the format size is 201mm*201mm. The operating frequency band of the Helmholtz resonator array is 500Hz~1200Hz, and the sound absorption bandwidth of the porous sound-absorbing material is 1200Hz~10000Hz. The sound absorption effect is as follows: Figure 9 As shown, it can be seen that the sound absorption module 20 has a better sound absorption effect in the range of 500Hz to 10000Hz.

[0070] Among them, the radius of the opening 2111 ranges from 1.6mm to 3.5mm, for example, it can be one of 1.6mm, 1.9mm, 2.2mm, 2.5mm, 2.8mm, 3.1mm, and 3.5mm; the length of the insertion tube 2112 ranges from 2mm to 4mm, for example, it can be one of 2mm, 2.5mm, 3mm, 3.5mm, and 4mm.

[0071] The sound absorption effects of the first embodiment and the second embodiment are compared. Figure 10 As shown, the different arrangements of the Helmholtz resonator array and the porous sound-absorbing material affect the sound absorption performance of the sound-absorbing module. Around 1200 Hz, where the sound absorption bandwidth of the Helmholtz resonator array and the porous sound-absorbing material meet, the sound absorption performance is affected by the arrangement, and the sound absorption performance at higher frequencies is also affected. It can be seen that at this point, the low-frequency sound absorption performance of sound-absorbing module 20 is basically the same as that of sound-absorbing module 10, while the high-frequency sound absorption performance of sound-absorbing module 20 is significantly better than that of sound-absorbing module 10.

[0072] Therefore, the arrangement of the Helmholtz resonator array and the porous sound-absorbing material can be reasonably selected according to the design requirements to achieve the required sound absorption effect.

[0073] An embodiment of the present application also provides a sound absorbing structure, comprising a plurality of sound absorbing modules as described in any of the above embodiments.

[0074] For example, adjacent sound absorbing modules can be connected by connecting pieces, thereby realizing the preparation of a large-scale sound absorbing structure, which is convenient for adapting to the surface of a space or an object.

[0075] It should be noted that the numbers representing quantities or properties used to describe and claim certain embodiments of the present application should be understood as being modified by the terms "roughly", "about", "approximately" or "substantially" in some cases. For example, unless otherwise stated, "roughly", "about", "approximately" or "substantially" can indicate a ±20% variation of the value described. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical fields and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0076] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A sound absorption module, characterized in that: include: a first sound absorbing structure having at least one first sound absorbing unit, wherein the first sound absorbing unit has an opening and an insertion tube extending from the opening into an inner cavity of the first sound absorbing unit; as well as, a second sound absorbing structure having at least one second sound absorbing unit; Wherein, the first sound absorbing structure and the second sound absorbing structure are arranged in the same plane; Furthermore, the first sound absorbing structure is configured to absorb sound waves in a first frequency band, and the second sound absorbing structure is configured to absorb sound waves in a second frequency band, wherein a lower limit value of the first frequency band is smaller than a lower limit value of the second frequency band, and an upper limit value of the first frequency band is smaller than an upper limit value of the second frequency band.

2. The sound absorbing module according to claim 1, characterized in that: The upper limit value of the first frequency band is less than or equal to the lower limit value of the second frequency band.

3. The sound absorbing module according to claim 1 or 2, characterized in that: The first sound absorbing structure and the second sound absorbing structure are arranged side by side.

4. The sound absorbing module according to claim 3, characterized in that: The first sound absorbing structure includes a plurality of first sound absorbing unit groups, each of which is arranged side by side in sequence along a first direction. The first sound absorbing units in each of the first sound absorbing unit groups are arranged in a second direction in a manner such that the sound absorption frequency increases or decreases in sequence, and the second direction is different from the first direction.

5. The sound absorbing module according to claim 3, characterized in that: The second sound absorbing unit includes a porous sound absorbing material, and each of the porous sound absorbing materials is located on one side of the first sound absorbing structure and is arranged side by side with the first sound absorbing structure.

6. The sound absorbing module according to claim 1 or 2, characterized in that: The first sound absorbing units and the second sound absorbing units are randomly arranged side by side.

7. The sound absorbing module according to claim 6, characterized in that: At least two of the first sound absorbing units are adjacent to each other and spaced apart, and at least one of the second sound absorbing units is located between the two adjacent first sound absorbing units.

8. The sound absorbing module according to claim 7, characterized in that: The second sound absorbing unit includes a porous sound absorbing material and a bottom plate located on a side of the porous sound absorbing material away from the opening of the first sound absorbing unit.

9. The sound absorbing module according to claim 1 or 2, characterized in that: The first frequency band includes 500 Hz to 1200 Hz, and the second frequency band includes 1200 Hz to 10000 Hz.

10. The sound absorbing module according to claim 9, characterized in that: The radius of the opening is in the range of 1.6 mm to 3.5 mm, and the length of the insertion tube is in the range of 2 mm to 4 mm.

11. The sound absorbing module according to claim 9, characterized in that: The thickness of the sound absorbing module ranges from 4 mm to 20 mm.

12. A sound absorbing structure, characterized in that: The invention comprises a plurality of sound absorbing modules according to any one of claims 1 to 11.

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