CN117738342A - Sound absorption structure and anechoic chamber - Google Patents

Abstract

The application provides a sound absorbing structure and anechoic chamber. The sound absorbing structure includes a bracket having a mounting portion for mounting the sound absorbing structure to an external environment; the sound absorption component is arranged on the bracket; the microperforated panel sound absorption structure is arranged on the frame and positioned between the sound absorption assembly and the mounting part; the sound absorption assembly is provided with a first sound absorption parameter, the first sound absorption parameter is configured to enable the sound absorption assembly to absorb sound waves of a first frequency band, the micro-perforated plate sound absorption structure is provided with a second sound absorption parameter, and the second sound absorption parameter is configured to enable the micro-perforated plate sound absorption structure to absorb sound waves of a second frequency band; the lower limit value of the second frequency band is smaller than the lower limit value of the first frequency band. When the sound absorption structure achieves the same sound absorption effect, the whole thickness of the sound absorption structure is far smaller than that of the traditional sound absorption part, so that the free sound field in the anechoic chamber is enlarged, and the sound absorption structure is beneficial to development of various acoustic works and acoustic experiments.

Description

Sound absorption structure and anechoic chamber

Technical Field

The invention relates to the technical field of sound absorption, in particular to a sound absorption structure and a sound attenuation chamber.

Background

With the development of technology, the demands of people on acoustic performance of technology products, calm houses and the like are increasing. In order to effectively evaluate the sound quality of part of products and the noise reduction performance of sound absorbing and insulating materials, the evaluation is required to be performed in a sound eliminating chamber or a semi-sound eliminating chamber. Anechoic chambers are special rooms that isolate external noise and reduce internal sound reflection and transmission. Anechoic chambers are typically constructed of materials with sound absorbing capabilities, and are intended to provide a quiet environment for accurate acoustic measurements, experimental studies, or applications requiring a low noise environment.

However, the conventional anechoic chamber often needs to be provided with a sound absorbing component (such as a porous sound absorbing material) with a larger volume to eliminate middle-low frequency noise, so that a larger space is occupied, the size of a free sound field is limited, and the development of acoustic work and acoustic experiments is not facilitated.

Disclosure of Invention

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

In a first aspect, the present application provides a sound absorbing structure comprising:

a bracket having a mounting portion for mounting the sound absorbing structure to an external environment;

the sound absorption assembly is arranged on the bracket; the method comprises the steps of,

the microperforated panel sound absorption structure is arranged on the bracket and is positioned between the sound absorption assembly and the mounting part;

wherein the sound absorption assembly has a first sound absorption parameter configured to cause the sound absorption assembly to absorb sound waves of a first frequency band, the microperforated panel sound absorption structure has a second sound absorption parameter configured to cause the microperforated panel sound absorption structure to absorb sound waves of a second frequency band;

the lower limit value of the second frequency band is smaller than the lower limit value of the first frequency band.

Above-mentioned sound absorption structure possesses following beneficial effect at least:

1. by arranging the micro-perforated plate sound absorption structure between the sound absorption assembly and the mounting part and reasonably arranging the first sound absorption parameter of the sound absorption assembly and the second sound absorption parameter of the micro-perforated plate sound absorption structure, the lower limit value of the sound absorption frequency band of the micro-perforated plate sound absorption structure is lower than the lower limit value of the sound absorption frequency band of the sound absorption assembly, so that the middle-low frequency sound absorption bandwidth of the sound absorption structure is widened, and the sound absorption structure achieves better low-frequency sound absorption performance on the premise of possessing the middle-high frequency sound absorption effect;

2. when the same sound absorption effect is achieved, the overall thickness of the sound absorption structure is far smaller than that of the traditional sound absorption part, so that the limitation between the thickness of the traditional sound absorption part of the anechoic chamber and the sound absorption bandwidth is broken through, the free sound field in the anechoic chamber is enlarged, and the development of various acoustic works and acoustic experiments is facilitated;

3. compared with the traditional sound absorption component in the anechoic chamber, the volume of the sound absorption structure is reduced, so that the use of materials can be reduced, the light weight requirement can be met more easily, and the construction difficulty can be reduced;

4. the first sound absorption parameter and the second sound absorption parameter of the sound absorption structure can be adjusted according to the target sound absorption frequency band, so that the sound absorption structure also has stronger frequency design adjustability, and is beneficial to meeting different customized sound absorption requirements.

In one embodiment, the second sound absorption parameter includes: a first distance between the sound absorbing component and the sound absorbing structure of the microperforated panel, and a second distance between the sound absorbing structure of the microperforated panel and the plane of the installation part; wherein the first pitch and the second pitch are both greater than 0.

In one embodiment, the sum of the first spacing and the second spacing is less than or equal to the thickness of the sound absorbing assembly.

In one embodiment, the range of the first interval is h/5-h/3, and the range of the second interval is h/5-h/3, wherein h represents the thickness of the sound absorption component.

In one embodiment, the micro-perforated plate sound absorbing structure comprises two or more micro-perforated plates which are sequentially arranged at intervals along the extending direction of the bracket; the second sound absorption parameter further includes: an adjacent spacing between adjacent two of the microperforated panels; wherein the value range of the adjacent interval is h/5-h/3.

In one embodiment, the microperforated panel sound absorbing structure comprises at least one microperforated panel, the microperforated panel is provided with a plurality of perforations, and the second sound absorbing parameter further comprises a thickness, a porosity of the microperforated panel and a pore diameter of each perforation.

In one embodiment, the thickness of the microperforated panel ranges from 0.5mm to 1mm; the porosity of the microperforated panel ranges from 1% to 3%; the aperture of the perforation is 0.2 mm-0.8 mm.

In one embodiment, the perforations on at least one of the microperforated panels in the microperforated panel sound absorbing structure are arranged in an array; wherein the apertures of the perforations in any row of perforations are the same, and the apertures of at least two rows of perforations are different.

In one embodiment, the sound absorbing assembly comprises at least one first sound absorbing wedge comprising a tip portion and a base portion provided at the bottom of the tip portion, and the first sound absorbing parameter comprises the thickness of the tip portion and the thickness of the base portion.

In one embodiment, the ratio of the thickness of the tip portion to the thickness of the base portion ranges from 8 to 12.

In one embodiment, the at least one first sound absorbing wedge comprises two or more first sound absorbing wedges, the microperforated panel sound absorbing structure comprises two or more microperforated panels, and one or more microperforated panels are disposed in the cavity between each first sound absorbing wedge and the mounting portion.

In one embodiment, the sound absorbing structure further comprises: the at least one second sound absorption wedge is arranged between the at least one first sound absorption wedge and the micro-perforated plate sound absorption structure.

In one embodiment, one or more second sound absorbing wedges are arranged in the cavity between each first sound absorbing wedge and the micro-perforated plate sound absorbing structure.

In one embodiment, the micro-perforated plate sound absorbing structure comprises two or more micro-perforated plates which are sequentially arranged at intervals along the extending direction of the bracket, and a porous sound absorbing material is arranged between every two adjacent micro-perforated plates.

In one embodiment, the sound absorbing assembly comprises at least one sound absorbing panel, and the first sound absorbing parameter comprises a thickness of the sound absorbing panel.

In one embodiment, at least one surface of the sound absorbing assembly is curved.

In a second aspect, the present application provides a sound-damping chamber comprising at least one indoor wall panel, a floor panel, and a sound absorbing structure as described hereinbefore provided to at least one of said indoor wall panel and/or said floor panel.

According to the silencing chamber, the sound absorption structures are arranged on at least one indoor wall plate and/or the bottom plate, so that the medium-low frequency sound absorption bandwidth of the silencing chamber is widened, and the silencing chamber can achieve better low-frequency sound absorption performance on the premise of possessing the medium-high frequency sound absorption effect; meanwhile, when the same sound absorption effect is achieved, the overall thickness of the sound absorption structure is far smaller than that of a traditional sound absorption part, so that the sound absorption chamber also has a larger free sound field, and various acoustic works and acoustic experiments are facilitated to be carried out.

In one embodiment, the anechoic chamber further comprises a vibration isolation rail arranged at the bottom of the anechoic chamber, and the vibration isolation rail comprises at least one vibration isolation spring.

In one embodiment, the vibration isolation rail is arranged on one side of the bottom plate close to the ground and comprises two or more vibration isolation springs arranged side by side.

In one embodiment, the anechoic chamber further comprises a sound insulation door provided on at least one of the indoor wall panels and rotatably connected thereto.

In one embodiment, the sound insulation door comprises a first galvanized steel sheet layer and a second galvanized steel sheet layer, and a low-frequency absorption layer is arranged between the first galvanized steel sheet layer and the second galvanized steel sheet layer; a first middle-high frequency absorption layer is arranged between the first galvanized steel sheet layer and the low frequency absorption layer; a second middle-high frequency absorption layer is arranged between the second galvanized steel sheet layer and the low frequency absorption layer; a sound insulation damping felt layer is arranged between the first galvanized steel sheet layer and the first middle-high frequency absorption layer; and a sound insulation damping felt layer is arranged between the second galvanized steel sheet layer and the second middle-high frequency absorption layer.

In one embodiment, the air conditioner further comprises a silencing air duct arranged on at least one indoor wall plate, the silencing air duct comprises an air inlet end, an air outlet end and an air cavity penetrating through the air inlet end and the air outlet end, a plurality of silencing modules are arranged on the silencing air duct in the extending direction of the air cavity, each silencing module comprises a plurality of super-structure silencing substrates arranged along the circumference of the silencing module, at least one communicating part is arranged on one side of each super-structure silencing substrate, facing the air cavity, of each super-structure silencing substrate, at least one resonant cavity is arranged in the inner part of each super-structure silencing substrate, and each resonant cavity is communicated with the air cavity through at least one communicating part so as to absorb the energy of sound waves in the air cavity through resonance.

In one embodiment, the silencing air duct further comprises at least one silencing insert plate arranged in the air cavity, at least one communicating part is arranged on two sides of the silencing insert plate respectively, at least two resonant cavities are formed in the silencing insert plate, and each resonant cavity is communicated with the air cavity through at least one communicating part so as to absorb energy of sound waves in the air cavity through resonance.

In one embodiment, the wind turbine further comprises a porous sound absorbing material arranged inside the wind cavity and positioned at the side of the wind cavity.

Drawings

In order to more clearly illustrate the embodiments of the present description or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present description, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is a schematic view of a sound absorbing structure according to an embodiment of the present application;

FIG. 2 is a schematic view of a sound absorbing structure according to an embodiment of the present application;

FIG. 3 is a schematic view of a portion of an arrangement of elements of a sound absorbing structure according to an embodiment of the present application;

FIG. 4 is a schematic top view of a microperforated panel of a sound absorbing structure according to an embodiment of the present disclosure;

FIG. 5 is a schematic top view of a sound absorbing assembly of a sound absorbing structure according to an embodiment of the present application;

FIG. 6 is a schematic cross-sectional view of the plane A-A of FIG. 5;

FIG. 7 is a graph of sound absorption effects of a sound absorbing structure according to an embodiment of the present application;

FIG. 8 is a schematic view of a sound absorbing structure according to an embodiment of the present application;

FIG. 9 is a graph of sound absorption effects of a sound absorbing structure according to an embodiment of the present application;

FIG. 10 is a schematic view of a muffling chamber according to one embodiment of the present application;

FIG. 11 is a schematic view of a vibration isolation rail according to an embodiment of the present application;

FIG. 12 is a schematic view of a muffler air duct according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of a muffler module according to an embodiment of the present application.

Description of element numbers:

10. sound absorbing structure, 10', sound absorbing structure, 110, sound absorbing assembly, 111-112, first sound absorbing wedge, 1121, tip, 11211 tip perforated plate, 1122, base, 11221 base perforated plate, 1123, sound absorbing material, 120, microperforated panel sound absorbing structure, 121, first microperforated panel, 1211, base plate, 1212, first microperforated, 1213, second microperforated, 122, second microperforated panel, 130, bracket, 131, mounting portion, 140, second sound absorbing wedge, M, mounting portion;

20. The indoor wallboard, 30, the bottom plate, 40, the vibration isolation rail, 41, the vibration isolation spring, 50, the sound insulation door, 60, the noise elimination wind channel, 61, the noise elimination wind channel air inlet end, 62, the noise elimination wind channel air outlet end, 63, the wind chamber, 610, the noise elimination module, 620, the noise elimination picture peg, 611, noise elimination module air inlet end, 612, noise elimination module air outlet end, 6110, super structure noise elimination base plate, 6111, intercommunication portion.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Anechoic room technology has found wide application in many fields, such as acoustic measurements, acoustic experiments, audio recordings, precision instrumentation, etc. The device can not only provide an accurate acoustic environment, but also effectively reduce the influence of noise on people and improve the effects of work and study. The techniques mainly applied in the anechoic chamber include:

Sound absorbing material: the interior walls of the muffling chamber are typically constructed of various sound absorbing materials, such as acoustical panels, acoustical wedges, etc., that absorb the energy of sound waves and reduce the reflection and propagation of sound.

The sound insulation structure comprises: the outer wall of the anechoic room usually adopts a sound insulation structure to isolate the interference of external noise, and meanwhile, the indoor sound can be ensured not to leak, such as a multi-layer sound insulation wall, a sound insulation door and the like.

An air treatment system: a good air handling system is typically required inside the anechoic chamber to ensure air circulation and control of environmental parameters such as temperature, humidity in the chamber.

In carrying out the present invention, the inventors have found that the conventional muffling chamber has the following problems:

1. the free sound field space is small, and the development of acoustic work and acoustic experiments is easy to be limited;

2. the background noise is higher, which is not beneficial to the measurement and test of low decibel noise; wherein, the background noise (background noise) represents an undesirable sound signal of the test equipment itself, or the noise of the surrounding environment when the sound source stops sounding;

3. the sound absorption bandwidth of the sound absorption component is smaller, which is not beneficial to further improving the sound absorption performance of the anechoic chamber.

In view of this, this application embodiment provides an improved anechoic chamber, through setting up improved sound absorption structure in inside, can enlarge anechoic chamber's free sound field and sound absorption bandwidth to combine vibration isolation rail, sound proof door and noise elimination wind channel, can fully reduce anechoic chamber's noise floor, thereby be favorable to further widening anechoic chamber's range of application, make things convenient for the development of all kinds of acoustic work and acoustic experiment.

As shown in fig. 10, the embodiment of the present application provides a sound-deadening chamber 1 including at least one indoor wall plate 20, a base plate 30, and a sound absorbing structure 10 provided to at least one indoor wall plate 20 and/or base plate 30. In addition, the muffling chamber 1 further includes a vibration isolation rail 40 provided at the bottom of the muffling chamber 1, and a sound insulation door 50 and a muffling air duct 60 provided at least one indoor wall plate 20. The sound absorption structure 10 is beneficial to improving the sound absorption bandwidth and sound absorption performance of the anechoic chamber 1, and the sound absorption structure 10 has smaller space occupation, so that the free sound field of the anechoic chamber 1 is beneficial to expanding; the vibration isolation rail 40, the soundproof door 50 and the soundproof air duct 60 are advantageous in isolating the interference of external noise, thereby reducing the noise floor of the soundproof room 1, and also ensuring that the indoor sound is not leaked.

The indoor wall panel 20 may be any of a wall, a wall panel, an aluminum alloy plate, a wood plate, and a ceiling, for the purpose of more extensive understanding, and the indoor wall panel 20 may be a non-detachable plate-like member on the sound-deadening chamber 1. For a wider understanding, the bottom plate 30 may be any one of a floor, an aluminum alloy plate, and a plate brick (including a tile), or the bottom plate 30 may be a plate-like member that is not movable on the sound-deadening chamber 1.

As illustrated in fig. 1 and 2, the sound absorbing structure 10 includes: a bracket 130 having a mounting portion 131 for mounting the sound absorbing structure 10 to an external environment (e.g., indoor wall panel, floor panel, etc.); a sound absorbing assembly 110 provided to the bracket 130; and a microperforated panel sound absorbing structure 120 disposed on the bracket 130 and between the sound absorbing assembly 110 and the mounting portion 131; wherein the sound absorbing assembly 110 has a first sound absorbing parameter configured to enable the sound absorbing assembly 110 to absorb sound waves of a first frequency band, the microperforated panel sound absorbing structure 120 has a second sound absorbing parameter configured to enable the microperforated panel sound absorbing structure 120 to absorb sound waves of a second frequency band; the lower limit value of the second frequency band is smaller than the lower limit value of the first frequency band. For example, the sound absorbing assembly 110 may absorb sound through a porous material (mesh region in the drawing) filled therein; the principle of the micro-perforated plate sound absorbing structure 120 for absorbing sound is as follows: and sound waves enter the back cavity of the micro-perforated plate through the perforations on the micro-perforated plate, when the sound frequency is close to the resonance frequency of the back cavity, air in the micropores is repeatedly rubbed with the hole wall, and heat loss is generated through a hot tack effect, so that heat energy is dissipated, and the purpose of sound absorption is achieved. Alternatively, the bracket 130 may be a keel frame, which is other support structure capable of forming a cavity between the sound absorbing assembly 110 and the microperforated panel sound absorbing structure 120, and between the microperforated panel sound absorbing structure 120 and the mounting portion 131. Alternatively, the mounting portion 131 may be fastened, riveted, screwed, bonded, or the like to the external environment, which is not limited in this application.

Alternatively, as shown in FIG. 2, for muffling chambers with higher cut-off frequencies (e.g., 80Hz/100 Hz), the sound absorbing assembly 110 may employ a thinner (e.g., 350 mm) sound absorbing plate. Alternatively, as shown in FIG. 1, for muffling chambers with lower cut-off frequencies (e.g., 50 Hz), the sound absorbing assembly 110 may employ a thicker (e.g., 850 mm) sound absorbing wedge. Wherein, the sound absorption flat plate and the sound absorption wedge can be formed by cladding porous materials by a perforated plate. It should be noted that the conventional sound absorption flat plate and the sound absorption wedge have the main disadvantage of poor low-frequency sound absorption performance under the limit of a certain thickness, and a thickness of more than 1.5m is generally required to meet the low-frequency sound absorption requirement (for example, the sound absorption coefficient of absorbing 50Hz sound waves can reach 0.99 after at least more than 1.7 m), so that the practical available space of the sound absorption chamber is greatly reduced. The sound absorption structure 10 according to the embodiment of the application, through adding the micro-perforated plate sound absorption structure 120 between the sound absorption assembly 110 and the mounting portion 131, can greatly reduce the thickness of the whole sound absorption structure 10 under the condition of realizing the same low-frequency sound absorption effect, thereby expanding the free sound field of the anechoic room 1 and facilitating the development of various acoustic works and acoustic experiments.

Alternatively, the first sound absorption parameter may include an equivalent density and bulk modulus of the porous material in the sound absorption assembly 110, which may be used to characterize the acoustic impedance of the porous material. Alternatively, the first sound absorption parameter may include an acoustic parameter of the porous material in the sound absorption assembly 110, such as porosity, air flow resistance, tortuosity factor, viscous characteristic length, thermal characteristic length, and the like. Optionally, the first sound absorption parameter may also include a thickness of the sound absorption assembly 110. Alternatively, when the sound absorbing assembly 110 includes a sound absorbing panel as shown in fig. 2, the first sound absorbing parameter of the sound absorbing structure 10' may further include a thickness of the sound absorbing panel, wherein an up-down direction indicated by an arrow in fig. 2 indicates a thickness direction of the sound absorbing panel. Alternatively, when the sound absorbing assembly 110 includes the sound absorbing wedges as shown in fig. 1, the first sound absorbing parameter of the sound absorbing structure 10 may further include the number of the sound absorbing wedges, the proportional relationship of thicknesses of the tip portions and the base portions in the sound absorbing wedges, the angles of the tip portions, etc., wherein the up-down direction shown by the arrow in fig. 1 indicates the thickness direction of the sound absorbing wedges, that is, the thickness direction of the tip portions and the base portions.

Alternatively, as shown in fig. 1-3, the microperforated panel sound absorbing structure 120 comprises one or more microperforated panels. As shown in fig. 3, for example, the perforated plate sound absorbing structure 120 includes a first perforated plate 121 and a second perforated plate 122, where the first perforated plate 121 includes a substrate 1211 and a plurality of micro-perforations formed on the substrate 1211, and each micro-perforation has a pore diameter less than or equal to 1mm.

Optionally, as shown in fig. 3, the sound absorbing assembly 110 and the micro-perforated plate sound absorbing structure 120 are both disposed on the bracket 130, and a cavity is formed between the sound absorbing assembly 110 and the micro-perforated plate sound absorbing structure 120, and a cavity is also formed between the micro-perforated plate sound absorbing structure 120 and the mounting portion 131, so that the second sound absorbing parameter may include a first distance D1 between the sound absorbing assembly 110 and the micro-perforated plate sound absorbing structure 120, and a second distance D2 between the micro-perforated plate sound absorbing structure 120 and the plane M where the mounting portion 131 is located; wherein, the first interval D1 and the second interval D2 are both larger than 0. Alternatively, the plane M of the mounting portion 131 and the mounting plane (e.g., the surface of the indoor wall panel 20) of the sound absorbing structure 10 when mounted to the external environment can be regarded as the same plane, so that the second distance D2 can also be regarded as the distance between the micro perforated plate sound absorbing structure 120 and the mounting plane (e.g., the surface of the indoor wall panel 20). Alternatively, the plane M on which the mounting portion 131 is located may be a tangential plane to a portion of the mounting portion 131 closest to the external environment when mounted. Optionally, the range of the values of the first interval D1 and the second interval D2 may be determined according to the overall structure size of the sound absorbing structure 10, so that the low-frequency sound absorbing curve peak value of the sound absorbing structure 10 is improved by properly adjusting the intervals, but a larger valley is easily formed at the middle-high-frequency sound absorbing curve, so that the sound absorbing performance of the overall sound absorbing structure 10 is reduced, and therefore, the proportional relationship between the intervals and the thickness of the sound absorbing assembly 110 needs to be balanced to achieve better sound absorbing performance.

Optionally, the second sound absorption parameter may further include at least one of the number of microperforated panels, the pore size of the perforations on the microperforated panels, the pore spacing of the perforations, the porosity of the microperforated panels, and the sheet thickness of the microperforated panels. Alternatively, the number of microperforated panels in the microperforated panel sound absorbing structure 120 may be two or more, and the single microperforated panel has limited sound absorbing performance, so that the low frequency sound absorption coefficient and the frequency bandwidth of the sound absorbing structure 10 can be improved more advantageously by the plurality of microperforated panels, and meanwhile, the sound absorption curve of the sound absorbing structure 10 can be smoothed by detailed adjustment of the second sound absorption parameter, so that the sound absorbing structure 10 can exert more excellent sound absorbing effect. Optionally, the thickness of the microperforated panel ranges from 0.5mm to 1mm; the porosity of the microperforated panel ranges from 1% to 3%; the value range of the aperture of the perforation is 0.2 mm-0.8 mm.

Fig. 7 shows a sound absorption effect diagram when the sound absorption assembly 110 employs the sound absorption wedge. As shown in fig. 7, the sound absorption coefficient of the sound absorption structure 10 (i.e., the composite wedge) of the present embodiment is significantly higher in the frequency band of 20Hz to 180Hz than that of the conventional wedge (i.e., the single wedge), and the sound absorption effect of the whole sound absorption structure 10 is also significantly better than that of the conventional wedge structure.

By adjusting the first sound absorption parameter and the second sound absorption parameter together, the lower limit value of the sound absorption frequency band (the second frequency band) corresponding to the sound absorption component 110 of the micro-perforated plate sound absorption structure 120 is smaller than the lower limit value of the sound absorption frequency band (the first frequency band) corresponding to the sound absorption component 110, which is beneficial to widening the middle-low frequency sound absorption bandwidth of the sound absorption structure 10 and enabling the sound absorption structure 10 to achieve better low-frequency sound absorption performance on the premise of possessing the middle-high frequency sound absorption effect; when the same sound absorption effect is achieved, the thickness of the whole structure of the sound absorption structure 10 is about 1/2 of the thickness of a single sound absorption flat plate or a single sound absorption wedge, so that the limitation between the thickness of a traditional sound absorption part of the anechoic chamber and the sound absorption bandwidth is broken through, and the free sound field in the anechoic chamber is enlarged; meanwhile, compared with the traditional sound absorption component in the anechoic chamber, the volume of the sound absorption structure 10 is reduced, so that the use of materials can be reduced, the light-weight requirement of the structure can be met more easily, and the construction difficulty can be reduced; in addition, the first sound absorption parameter and the second sound absorption parameter of the sound absorption structure 10 can be adjusted according to the target sound absorption frequency band, so that the sound absorption structure 10 further has strong frequency design adjustability, and is beneficial to meeting different customized sound absorption requirements.

As shown in fig. 10 and 11, for example, the bottom of the muffling chamber 1 is further provided with a vibration isolation rail 40, and the vibration isolation rail 40 includes at least one vibration isolation spring 41. Alternatively, the vibration isolation rail 40 is provided on a side of the bottom plate 30 near the ground and includes two or more vibration isolation springs 41 provided side by side. By arranging the vibration isolation rail 40 at the bottom of the anechoic chamber 1, the vibration transmitted to the anechoic chamber 1 is blocked outside the anechoic chamber 1, thereby reducing the noise floor of the anechoic chamber 1; on the other hand, the vibration isolation spring 41 is usually made of special stainless steel through special design and processing, can be used for more than 30 years continuously, has the characteristics of fire resistance, water resistance, no pollution, corrosion resistance and the like, does not need special maintenance, and is simple to maintain. Alternatively, when the noise damping gauge is high and the noise damping chamber 1 is located in a room, the vibration isolation rail 40 may be also provided between the outer wall of the room and the inner wall of the noise damping chamber 1.

Alternatively, the natural frequency f of the vibration isolation rail 40 ₀ Less than or equal to 5Hz, so as to be according to the efficiency formula of the vibration isolation spring 41:where f represents the external disturbance frequency, ζ represents the damping ratio of the vibration isolation spring, and when the external disturbance frequency f is 40Hz, the efficiency T of the vibration isolation spring 41 is about 95.2%, so that the vibration transmitted from the outside can be effectively blocked.

Illustratively, as shown in fig. 10, the muffling chamber 1 further includes a sound-proof door 50 provided to at least one of the indoor wall panels 20 and rotatably connected to the indoor wall panel 20. Optionally, the sound insulation door 50 comprises a first galvanized steel sheet layer and a second galvanized steel sheet layer, and a low-frequency absorption layer is arranged between the first galvanized steel sheet layer and the second galvanized steel sheet layer for absorbing low-frequency sound; a first middle-high frequency absorption layer is arranged between the first galvanized steel sheet layer and the low frequency absorption layer to absorb middle-high frequency sound; a second middle-high frequency absorption layer is arranged between the second galvanized steel sheet layer and the low frequency absorption layer for absorbing middle-high frequency sound; a sound insulation damping felt layer is arranged between the first galvanized steel sheet layer and the first middle-high frequency absorption layer so as to further improve the sound insulation effect; and a sound insulation damping felt layer is arranged between the second galvanized steel sheet layer and the second middle-high frequency absorption layer so as to ensure the sound insulation effect. The sound insulation door 50 is arranged on the anechoic chamber 1, which is favorable for realizing the insulation effect applicable to low, medium and high frequency sounds, thereby further reducing the noise floor of the anechoic chamber 1 and ensuring that the indoor sound is not leaked.

As illustrated in fig. 12 and 13, the muffling chamber 1 further includes a muffling air duct 60 provided in at least one indoor wall plate 20, the muffling air duct 60 includes an opposite air inlet end 61 and an air outlet end 62, and an air chamber 63 penetrating the air inlet end 61 and the air outlet end 62, the muffling air duct 60 is provided with a plurality of muffling modules 610 in an extending direction of the air chamber 63, the muffling modules 610 include a plurality of super-structured muffling substrates 6110 provided along a circumferential direction thereof, one side of the super-structured muffling substrate 6110 facing the air chamber 63 is provided with at least one communicating portion 6111, and an inside of the super-structured muffling substrate 6110 has at least one resonant cavity, each of which communicates with the air chamber 63 through the at least one communicating portion 6111 to absorb energy of sound waves in the air chamber 63 through resonance.

The silencing air duct 60 can be used for silencing the air conditioning system pipeline in the silencing chamber 1, so that the silencing air duct 60 is beneficial to reducing noise of the air conditioning system pipeline while guaranteeing air circulation of the silencing chamber 1, and noise floor of the silencing chamber 1 is further reduced. In some setting examples, the silencing air duct 60 may be used as a pipeline of an air conditioning system, or the silencing air duct 60 may be used as a part of a pipeline of the air conditioning system, and specifically, the setting may be performed according to the actual silencing requirement of the silencing chamber 1.

Specifically, a resonant cavity is arranged in the silencing air duct 60, when the frequency of sound waves in the air cavity 63 is basically consistent with the natural frequency of the resonant cavity, the air in the resonant cavity can be subjected to severe vibration so as to generate friction heat with the side wall of the resonant cavity, the conversion from sound energy to mechanical energy to internal energy is realized, and finally the energy absorption of the sound waves in the air cavity 63 is realized; in addition, when the number of the resonant cavities is multiple, a plurality of coupling resonant frequencies can be generated by utilizing the near-field coupling effect among the resonant cavities, so that the sound absorption frequency range of sound waves can be widened, and the sound elimination performance of the sound elimination air duct 60 can be improved; in addition, by arranging the plurality of silencing modules 610 in the extending direction of the air cavity 63, each silencing part extends inwards, so that the occupation of the transverse space of the silencing air duct 60 can be effectively reduced, the expansion ratio of the silencing air duct 60 can be reduced, for example, the expansion ratio is close to 1, and the silencing air duct 60 can be modularized without integrally preparing an air duct with a larger length, thereby being beneficial to reducing the preparation difficulty of the silencing air duct 60 and further reducing the preparation cost; finally, it should be noted that, because the silencing air duct 60 has a silencing effect, the use of additional porous sound absorbing materials can be effectively reduced under the same silencing requirement, thereby being beneficial to further reducing the space occupation, reducing the expansion ratio and further reducing the preparation cost.

In conclusion, the anechoic chamber 1 can expand the free sound field, which is beneficial to the development of various acoustic works and acoustic experiments; meanwhile, the noise floor of the anechoic chamber 1 is low, which is beneficial to the measurement and test of low decibel noise; in addition, the sound absorption structure 10 of the anechoic chamber 1 has wider sound absorption bandwidth and better middle-low frequency sound absorption performance, thereby being beneficial to further improving the sound absorption performance of the anechoic chamber 1.

In some embodiments of the present application, as shown in fig. 3, the sum of the first spacing D1 and the second spacing D2 is less than or equal to the thickness of the sound absorbing assembly 110. In this manner, it is advantageous to stabilize the sound absorption performance of the sound absorption structure 10 in the middle-high frequency band. Optionally, the first distance D1 has a value ranging from h/5 to h/3, and the second distance D2 has a value ranging from h/5 to h/3, where h represents the thickness of the sound absorbing assembly 110, and the up-down direction indicated by the arrow in fig. 3 represents the thickness direction of the sound absorbing assembly 110. Alternatively, as shown in fig. 1 to 3, the perforated panel sound absorbing structure 120 includes two or more perforated panels spaced along the extending direction of the bracket 130, so that the second sound absorbing parameter further includes an adjacent distance Dp between two adjacent perforated panels, where the sum of D1, D2, dp is less than or equal to the thickness of the sound absorbing assembly 110, and the adjacent distance Dp has a value ranging from h/5 to h/3.

In some embodiments of the present application, the perforations on at least one of the microperforated panel sound absorbing structures are arranged in an array; wherein the apertures of the perforations in any row of perforations are the same, and the apertures of at least two rows of perforations are different. As shown in fig. 4, taking the first micro-perforated plate 121 as an example, a substrate 1211 of the first micro-perforated plate 121 is provided with a first micro-perforation 1212 and a second micro-perforation 1213, the first micro-perforation 1212 and the second micro-perforation 1213 are arranged in an array, the aperture of each perforation in any row of perforations is the same, and the apertures of two adjacent rows of perforations are different. In this way, it is beneficial to provide more degrees of freedom for the second sound absorption parameter adjustment, and thus to achieve a broadband low-frequency sound absorption effect for the sound absorption structure 10.

In some embodiments of the present application, as shown in fig. 5 and 6, the sound absorbing assembly 110 includes at least first sound absorbing wedges 111 and 112. Taking the first sound absorption wedge 112 as an example, the first sound absorption wedge 112 comprises a tip portion 1121 and a base portion 1122 arranged at the bottom of the tip portion 1121, and the first sound absorption parameter comprises the thickness of the tip portion 1121 and the thickness of the base portion 1122, wherein the tip portion 1121 comprises a tip portion perforated plate 11211 covered on the surface thereof, and the base portion comprises a base portion perforated plate 11221 covered on the surface thereof. For example, proper adjustment of the thickness of the base is beneficial to improving the sound absorption performance of the sound absorption structure 10 in the low frequency band, but an excessively thick base can reduce the sound absorption performance of the sound absorption structure 10 in the middle and high frequency bands, and according to the sound source characteristics, a better impedance matching condition is beneficial to be achieved by reasonably setting the proportional relationship between the tip of the sound absorption wedge and the base, so that better acoustic performance is obtained, and the sound absorption structure 10 can better give consideration to the middle and high frequency sound absorption effect and the low frequency sound absorption effect. By way of example, proper adjustment of the tip angle of the sound absorption wedge is also beneficial to improving the sound absorption performance of the sound absorption structure 10 in the low frequency band, but an excessive tip angle can reduce the impedance matching effect of the sound absorption wedge, and according to the sound source characteristics, the tip angle of the sound absorption wedge is beneficial to achieving better impedance matching conditions by reasonably setting the tip angle of the sound absorption wedge, so that better acoustic performance is obtained.

Alternatively, as shown in FIG. 6, the ratio of the thickness of the tip 1121 to the thickness of the base 1122 may range from 8 to 12. By controlling the ratio of the thickness of the tip 1121 to the thickness of the base 1122 to satisfy the above range, it is advantageous to enhance the sound absorption performance of the sound absorption structure 10 in the low frequency band while not reducing the sound absorption performance of the sound absorption structure 10 in the medium and high frequency bands.

In some embodiments of the present application, at least one surface of the sound absorbing assembly 110 is curved, which is advantageous for achieving a better impedance matching condition of the sound absorbing assembly 110 and improving sound absorbing performance. Alternatively, when the sound absorbing assembly 110 is a sound absorbing panel, the top surface of the sound absorbing panel may be provided as a curved surface; alternatively, when the sound absorbing assembly 110 is a sound absorbing wedge, the side of the sound absorbing wedge may be provided as a curved surface.

In some embodiments of the present application, as shown in fig. 3, the at least one first sound absorbing wedge includes two or more first sound absorbing wedges, the microperforated panel sound absorbing structure 120 includes two or more microperforated panels, and one or more microperforated panels are disposed in the cavity between each first sound absorbing wedge and the mounting portion 131. By providing a plurality of first sound absorbing wedges and configuring at least one microperforated panel in the cavity below each first sound absorbing wedge, the sound absorbing performance of sound absorbing structure 10 is facilitated to be further improved. As can be seen from fig. 10, each first sound-absorbing wedge in the sound-absorbing chamber 1 may be sequentially connected to each other along a direction parallel to the indoor wall plate 20, and at least one micro-perforated plate is disposed in a cavity between each first sound-absorbing wedge and the indoor wall plate 20. Alternatively, the microperforated panel may be a plurality of small microperforated panels so as to be disposed respectively corresponding to each of the first sound-absorbing wedges; alternatively, the micro-perforated plate may be one or a small number of large micro-perforated plates, and different positions on the large micro-perforated plate may correspond to different first sound absorption wedges and be disposed below the first sound absorption wedges.

In some embodiments of the present application, as shown in fig. 8, the sound absorbing structure 10 further includes: at least one second sound absorbing wedge 140 is disposed between the at least one first sound absorbing wedge and the microperforated panel sound absorbing structure 120. Optionally, the second sound absorbing wedge 140 is disposed on the microperforated panel closest to the first sound absorbing wedge. Optionally, the second sound absorbing wedge 140 also has a tip and a base. Alternatively, the second sound absorbing wedge 140 may have only a tip portion. Optionally, the second sound absorbing wedge 140 is also filled with a porous material to absorb sound waves of a corresponding frequency. By providing the second sound absorbing wedge 140 between the at least one first sound absorbing wedge and the micro perforated plate sound absorbing structure 120, the number of reflections and consumption of sound waves in each sound absorbing wedge can be increased, thereby facilitating further improvement of the sound absorbing performance of the sound absorbing structure 10.

Optionally, one or more second sound absorbing wedges are disposed in the cavity between each first sound absorbing wedge and the sound absorbing structure of the microperforated panel, as shown in fig. 8, two second sound absorbing wedges 140 are disposed below each first sound absorbing wedge 111 and each second sound absorbing wedge 112, which is beneficial to further improving the degree of recombination between the porous material and the microperforated panel in the sound absorbing wedges, thereby further increasing the reflection times and consumption of sound waves in each sound absorbing wedge, and further improving the sound absorbing performance of the sound absorbing structure 10.

Alternatively, with continued reference to fig. 8, the microperforated panel sound absorbing structure 120 comprises two or more microperforated panels spaced apart along the direction of extension of the stent 130 with a porous sound absorbing material (mesh region) disposed between adjacent microperforated panels. Thus, the degree of compositing of the porous material and the microperforated panel is further improved, the reflection times and consumption of sound waves are further increased, and the sound absorption performance of the sound absorption structure 10 is further improved.

As shown in fig. 9, in which the conventional wedge represents a single wedge structure in which the micro perforated plate sound absorbing structure 120 is not provided, the composite wedge 1 represents the sound absorbing structure shown in fig. 1, and the composite wedge 2 represents the sound absorbing structure shown in fig. 8. It can be seen that the sound absorption coefficient of the composite wedge 2 between 50Hz and 80Hz is closer to 0.99 than that of the composite wedge 1 between 50Hz and 80Hz, that is, the low-frequency sound absorption performance of the composite wedge 2 is better than that of the composite wedge 1 while the middle-high frequency sound absorption performance is ensured.

In some embodiments of the present application, the various types of sheet materials used in the sound absorbing structure 10 may be manufactured from materials selected from plastics, metals, and the like, depending on fire protection and processing requirements.

In some embodiments of the present application, as shown in fig. 12, the silencing wind channel 60 further includes at least one silencing insert plate 620 disposed in the wind cavity 63, at least one communication portion (not shown) is disposed on two sides of the silencing insert plate 620, and at least two resonant cavities are disposed inside the silencing insert plate 620, each resonant cavity is communicated with the wind cavity 63 through the at least one communication portion, so as to absorb energy of sound waves in the wind cavity 63 through resonance. By arranging the silencing insert plates 120 with sound absorption functions on both sides in the wind cavity 63, the silencing effect of the silencing wind channel 60 can be effectively improved, and the expansion ratio of the silencing wind channel 60 can be further reduced. Alternatively, the number of the silencing insert plates 620 is less than or equal to a predetermined value, and if the number of the silencing insert plates 620 is excessive, resistance of the silencing insert plates 620 to wind is increased, thereby being disadvantageous for ventilation in the wind chamber 63. Alternatively, the predetermined value may be determined based on actual noise abatement requirements and ventilation performance requirements, e.g., when the noise abatement requirements are high, then the predetermined value may be appropriately greater; when the ventilation performance requirement is higher, the predetermined value may be suitably smaller. Alternatively, the predetermined value may be one of 1, 2, 3, 4.

In some embodiments of the present application, the muffling chamber 1 further includes a porous sound absorbing material provided inside the wind chamber 63 and located laterally of the wind chamber 63. Thus, the silencing effect of the silencing air duct 60 is further improved. It should be noted that the porous sound absorbing material should be disposed at a position to minimize the influence on the air flow of the muffling air duct 60, for example, may be disposed close to the super-structure muffling substrate 6110 on the side of the air duct.

In some embodiments of the present application, the material of at least a portion of the sound-damping duct 60 includes metallic and non-metallic materials, such as one or more of steel, iron, aluminum alloy, plexiglas, polylactic acid material, plastic, rubber, wood, stone, and carbon fiber composite. The preparation of the noise elimination air duct 60 by adopting the materials is beneficial to improving the mechanical strength of the noise elimination air duct 60 and is also beneficial to selecting and matching based on the requirements of environmental protection, processing, fire prevention, heat dissipation and the like.

The embodiment of the application also provides a sound absorption structure, which comprises: a bracket having a mounting portion for mounting the sound absorbing structure to an external environment; the sound absorption component is arranged on the bracket; the microperforated panel sound absorption structure is arranged on the bracket and positioned between the sound absorption assembly and the mounting part; the sound absorption assembly is spaced from the micro-perforated plate sound absorption structure by a first distance, and the micro-perforated plate sound absorption structure is spaced from the plane of the installation part by a second distance; wherein, the first interval and the second interval are both greater than 0.

According to the sound absorption structure, the micro-perforated plate sound absorption structure is arranged between the sound absorption assembly and the installation part, so that the medium-low frequency sound absorption bandwidth of the sound absorption structure is widened, and the sound absorption structure achieves better low-frequency sound absorption performance on the premise of possessing the medium-high frequency sound absorption effect; and when reaching same sound absorption effect, the overall structure thickness of sound absorption structure is showing and is less than traditional sound absorbing component's thickness, has broken through the restriction between traditional anechoic room sound absorption wedge thickness and the sound absorption bandwidth, is favorable to expanding anechoic room's free sound field, satisfies the lightweight demand of structure simultaneously, is favorable to reducing the construction degree of difficulty.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (24)

1. A sound absorbing structure comprising:

a bracket having a mounting portion for mounting the sound absorbing structure to an external environment;

the sound absorption assembly is arranged on the bracket; the method comprises the steps of,

the microperforated panel sound absorption structure is arranged on the bracket and is positioned between the sound absorption assembly and the mounting part;

wherein the sound absorption assembly has a first sound absorption parameter configured to cause the sound absorption assembly to absorb sound waves of a first frequency band, the microperforated panel sound absorption structure has a second sound absorption parameter configured to cause the microperforated panel sound absorption structure to absorb sound waves of a second frequency band;

the lower limit value of the second frequency band is smaller than the lower limit value of the first frequency band.

2. The sound absorbing structure of claim 1 wherein the second sound absorbing parameter comprises:

a first distance between the sound absorbing component and the sound absorbing structure of the microperforated panel, and a second distance between the sound absorbing structure of the microperforated panel and the plane of the installation part;

wherein the first pitch and the second pitch are both greater than 0.

3. The sound absorbing structure of claim 2, wherein the sum of the first spacing and the second spacing is less than or equal to the thickness of the sound absorbing assembly.

4. The sound absorbing structure of claim 3 wherein the first spacing has a value in the range of h/5 to h/3 and the second spacing has a value in the range of h/5 to h/3, wherein h represents the thickness of the sound absorbing assembly.

5. The sound absorbing structure of any one of claims 2-4, wherein,

the microperforated panel sound absorption structure comprises two or more microperforated panels which are sequentially arranged at intervals along the extending direction of the bracket;

the second sound absorption parameter further includes:

an adjacent spacing between adjacent two of the microperforated panels; wherein the value range of the adjacent interval is h/5-h/3.

6. The sound absorbing structure of any one of claims 2-4, wherein,

the microperforated panel sound absorbing structure comprises at least one microperforated panel, a plurality of perforations are formed in the microperforated panel, and the second sound absorbing parameter further comprises thickness, porosity and aperture of each perforation of the microperforated panel.

7. The sound absorbing structure of claim 6, wherein the microperforated panel has a thickness ranging from 0.5mm to 1mm; the porosity of the microperforated panel ranges from 1% to 3%; the aperture of the perforation is 0.2 mm-0.8 mm.

8. The sound absorbing structure of claim 6, wherein the sound absorbing structure comprises,

the perforation on at least one micro-perforated plate in the micro-perforated plate sound absorption structure is arranged in an array form; wherein the apertures of the perforations in any row of perforations are the same, and the apertures of at least two rows of perforations are different.

9. The sound absorbing structure of any one of claims 2-4, wherein the sound absorbing assembly comprises at least one first sound absorbing wedge comprising a peak portion and a base portion disposed at a bottom of the peak portion, the first sound absorbing parameter comprising a thickness of the peak portion and a thickness of the base portion.

10. The sound absorbing structure of claim 9, wherein the ratio of the thickness of the tip portion to the thickness of the base portion has a value in the range of 8 to 12.

11. The sound absorbing structure of claim 9, wherein the at least one first sound absorbing wedge comprises two or more first sound absorbing wedges, the microperforated panel sound absorbing structure comprises two or more microperforated panels, and one or more microperforated panels are disposed in the cavity between each first sound absorbing wedge and the mounting portion.

12. The sound absorbing structure of claim 9, wherein the sound absorbing structure further comprises: the at least one second sound absorption wedge is arranged between the at least one first sound absorption wedge and the micro-perforated plate sound absorption structure.

13. The sound absorbing structure of claim 12, wherein one or more of the second sound absorbing wedges are disposed in a cavity between each of the first sound absorbing wedges and the microperforated panel sound absorbing structure.

14. The sound absorbing structure of claim 12, wherein the microperforated panel sound absorbing structure comprises two or more microperforated panels sequentially spaced apart along the direction of extension of the support, and a porous sound absorbing material is disposed between two adjacent microperforated panels.

15. The sound absorbing structure of any one of claims 2-4 wherein the sound absorbing assembly comprises at least one sound absorbing panel and the first sound absorbing parameter comprises a thickness of the sound absorbing panel.

16. The sound absorbing structure of claim 1 wherein at least one surface of the sound absorbing assembly is curved.

17. A sound-damping chamber, characterized by comprising at least one indoor wall plate, a base plate, and a sound-absorbing structure according to any one of claims 1-16 provided to at least one of the indoor wall plate and/or the base plate.

18. The anechoic chamber of claim 17, further comprising a vibration isolation rail disposed at a bottom of the anechoic chamber, the vibration isolation rail comprising at least one vibration isolation spring.

19. The muffling chamber of claim 18, wherein the vibration isolation rail is disposed on a side of the floor proximate the ground and comprises two or more vibration isolation springs disposed side-by-side.

20. The anechoic chamber of claim 17, further comprising a sound-proof door provided in at least one of said indoor panels and rotatably connected thereto.

21. The anechoic chamber of claim 20, wherein the sound-proof door comprises a first galvanized steel sheet layer and a second plated steel sheet layer with a low frequency absorption layer therebetween; a first middle-high frequency absorption layer is arranged between the first galvanized steel sheet layer and the low frequency absorption layer; a second middle-high frequency absorption layer is arranged between the second galvanized steel sheet layer and the low frequency absorption layer; a sound insulation damping felt layer is arranged between the first galvanized steel sheet layer and the first middle-high frequency absorption layer; and a sound insulation damping felt layer is arranged between the second galvanized steel sheet layer and the second middle-high frequency absorption layer.

22. The muffling chamber of claim 17, further comprising a muffling air duct provided in at least one of the indoor wall panels, the muffling air duct comprising opposite air inlet and air outlet ends and an air chamber penetrating the air inlet and air outlet ends, the muffling air duct being provided with a plurality of muffling modules in an extending direction of the air chamber, the muffling modules comprising a plurality of super-structured muffling substrates provided along a circumference thereof, one side of the super-structured muffling substrate facing the air chamber being provided with at least one communication portion, and an inside of the super-structured muffling substrate being provided with at least one resonant chamber, each resonant chamber being communicated with the air chamber through at least one communication portion to absorb energy of sound waves in the air chamber through resonance.

23. The muffling chamber of claim 22, wherein the muffling air duct further comprises at least one muffling insert plate provided to the wind chamber, at least one communicating portion is provided on both sides of the muffling insert plate, respectively, and the inside of the muffling insert plate has at least two resonant cavities, each of which communicates with the wind chamber through at least one of the communicating portions to absorb energy of sound waves in the wind chamber through resonance.

24. The anechoic chamber of claim 22, further comprising a porous sound absorbing material disposed inside and laterally of the wind cavity.