JP2006030397A - Noise absorbing structure and noise absorbing/insulating structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise absorbing structure and a noise absorbing/insulating structure capable of exerting a noise absorption property suitable for noise having a wide frequency range. <P>SOLUTION: First and second noise absorbing portions 26a, 26b whose noise absorbing characteristics are different are provided in a noise absorbing/insulating box 12. Respective noise absorbing portions 26a, 26b are constituted by being equipped with noise absorbing walls 21a, 21b which are arranged toward a noise source and noise insulating walls 22a, 22b which are arranged by being opposed respectively to the noise absorbing walls 21a, 21b. First noise absorbing holes 20a are provided by being penetrated in the first noise absorbing wall 21a as an aggregate of holes 28 whose diameters are equal, second noise absorbing holes 20b are provided by being penetrated in the second noise absorbing wall 21b as an aggregate of holes 28 whose diameters are larger than that of the holes 28. That is, the noise absorbing box 12 is formed so that internal opening areas of noise absorbing holes 20a, 20b are different for every noise absorbing portions 26a, 26b, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sound-absorbing structure and a sound-absorbing / insulating structure that absorbs vehicle interior noise and the like in a vehicle interior.

  In recent years, there has been a demand for quietness in the passenger compartment, and accordingly, further reduction in noise level such as in-vehicle noise has been demanded. Therefore, a sound absorbing structure including a base material in which a plurality of holes are formed and a space provided behind the base material is known. In this type of sound absorbing structure, when the sound from the sound source passes through the hole formed in the sound absorbing wall, the sound absorbing effect by the Helmholtz resonance principle is exhibited, so that the sound energy is absorbed quickly. It has become. In Patent Documents 1 to 3, the following sound absorbing structure is proposed.

Patent Documents 1 and 2 describe an interior part for a vehicle configured such that a plurality of holes are formed in a hollow member and the holes are arranged toward the vehicle interior. Patent Document 3 describes a sound insulating plate in which a cylindrical hollow body having an open end is closely placed on a support plate.
Japanese Utility Model Publication No.2-115049 JP 2000-16189 A JP-A-5-92441

  However, in Patent Documents 1 and 2, since the sound absorbing holes provided in the hollow member have the same diameter and the same opening area, the sound absorbing region is limited to a narrow region. . Further, in Patent Document 3, it is difficult to increase the volume of the space in the cylindrical hollow body relative to the opening area at the tip of the cylindrical hollow body, so that the sound absorption effect by the Helmholtz resonance principle is sufficiently exhibited. There is a disadvantage that can not be. For these reasons, there is still room for improvement in terms of exhibiting sound absorbing performance against in-vehicle noise having a wide frequency range.

  The present invention has been made in view of the above problems, and an object thereof is to provide a sound absorbing structure and a sound absorbing / insulating structure capable of exhibiting suitable sound absorbing performance for sound having a wide frequency range. There is to do.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a sound absorbing structure that absorbs sound of a predetermined frequency region generated from a sound source, and includes a sound absorbing body having a plurality of hollow sound absorbing portions. The wall materials arranged toward the sound source among the wall materials constituting each sound absorbing portion are used as sound absorbing walls, and one or a plurality of holes are formed in the sound absorbing walls so that the holes are formed in the sound absorbing walls. The gist of the present invention is that each of the sound absorbing holes is provided and the opening area of the sound absorbing hole is made different for each sound absorbing portion.

  According to this configuration, the sound absorber is formed such that the opening area of the sound absorbing hole is different for each sound absorbing portion. Thereby, the sound of a different frequency for each sound absorbing part is absorbed. Therefore, the frequency range of the sound absorbed by the sound absorbing body can be made wider than that of the conventional configuration, and suitable sound absorbing performance can be exhibited for sounds in a wide frequency range.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the plurality of holes constituting the sound absorbing hole have the same opening area.
According to this configuration, since the plurality of holes constituting each sound absorbing hole have the same opening area, the frequency region of the sound to be absorbed can be clearly set for each sound absorbing portion.

The gist of the invention described in claim 3 is that, in the invention described in claim 1 or 2, the wall material facing the sound absorbing wall is configured as a sound insulating wall having no sound absorbing hole.
According to this configuration, the sound insulating wall does not have the sound absorbing hole, and is formed so that the space in the sound absorbing portion and the outside do not communicate with each other. For this reason, sound propagation can be blocked by the sound insulation wall, and the sound from the sound source can be prevented from leaking outside.

  The invention according to claim 4 includes a sound absorbing body having a plurality of hollow sound absorbing portions, and each of the wall materials constituting each sound absorbing portion is arranged toward the sound source as a sound absorbing wall, By providing one or a plurality of holes in the sound absorbing wall, each sound absorbing wall is provided with a sound absorbing hole made of the hole, and the sound absorbing hole has a different opening area for each sound absorbing portion. The gist is that the wall material on the side facing the wall is configured as a sound insulating wall having no sound absorbing hole.

  According to this configuration, since the sound absorbing body is formed so that the opening areas of the respective sound absorbing holes are different for each sound absorbing portion, it is possible to exert the same effects as the invention of the first aspect. Further, among the wall materials constituting the sound absorbing portion, the wall material arranged on the side facing the sound absorbing wall is configured as a sound insulating wall having no sound absorbing holes, and therefore the same effect as the invention according to claim 3. Can be demonstrated. Therefore, it is possible to combine sound absorption performance and sound insulation performance suitable for sounds in a wide frequency range.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to exhibit suitable sound absorption performance with respect to the noise etc. which have a wide frequency.

(First embodiment)
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment in which the present invention is embodied as a sound-absorbing and insulating structure attached to a console as an interior product for a vehicle will be described with reference to FIGS.

  As shown in FIG. 1, a console 11 as a vehicle interior is arranged between the driver seat and the passenger seat in the vehicle interior. Drive system parts (engine, gear, etc.) as a sound source (not shown) are mounted on the front lower part of the vehicle. Various sounds generated from these drive system components propagate through the internal space of the console 11 and leak into the vehicle interior space from the gap, thereby generating vehicle interior noise. Therefore, two sound absorption / insulation boxes 12 are attached to the inside of the console 11 as sound absorbers, and these two sound absorption / insulation boxes 12 constitute an absorption / insulation structure.

  As shown in FIG. 2, in the console 11, an attachment portion 14 for attaching the sound absorbing and insulating box 12 is provided inwardly on the inner wall surface of the both side walls 11 a. The attachment portion 14 includes a pair of guide walls 15, and a guide groove 16 is formed between the guide walls 15. One mounting portion 14 is disposed at each of the front and rear portions of the console 11 corresponding to the mounting position of the sound absorbing and insulating box 12. The sound absorbing and insulating boxes 12 are held so as not to be displaced from predetermined positions in the console 11 by inserting both side edges in the width direction into the guide grooves 16 of the mounting portions 14.

  The sound absorbing and insulating box 12 is formed in a substantially square box shape using a synthetic resin such as polypropylene (PP), polyethylene (PE), or acrylonitrile butadiene styrene copolymer (ABS) as a material. That is, the sound absorbing and insulating box 12 includes a first wall 21, a second wall 22 disposed to face the first wall 21, and four side walls 24 that connect the first wall 21 and the second wall 22. And is formed so as to form a hollow body structure having a space 23 therein. A plurality of circular holes 28 are formed in the first wall 21 so that the space in the console 11 communicates with the space 23 in the sound absorbing and insulating box 12. . The second wall 22 and the side wall 24 are not provided with a hole 28, and the second wall 22 and the side wall 24 shield the space 23 in the sound absorbing and insulating box 12 from the space in the console 11. .

  The sound absorbing and insulating box 12 is arranged with the first wall 21 facing the front of the vehicle while being held by the mounting portion 14. The two sound absorbing and insulating boxes 12 are arranged one by one at the front and rear portions of the console 11 so as to block the course of sound propagating through the console 11. Further, as shown in FIG. 3, the heights of the two sound absorbing and insulating boxes 12 are set according to the height of the console 11. For this reason, each sound absorption and insulation box 12 is held by the mounting portion 14, and both side edges in the width direction and the vertical direction are in contact with the inner wall of the console 11, and between the inner wall of the console 11. It arrange | positions so that a clearance gap may not be formed. That is, each sound absorption / insulation box 12 is used in order to prevent engine sound and gear sound generated from drive system components from leaking into the vehicle interior as vehicle interior noise.

  In the sound absorbing and insulating box 12, when the sound propagating through the console 11 from the front of the vehicle passes through the hole 28 of the first wall 21, the air inside the hole 28 acts as a mass. On the other hand, the air in the space 23 of the sound absorbing and insulating box 12 shielded from the space in the console 11 by the second wall 22 and the side wall 24 except for the holes 28 provided in the first wall 21 acts as a spring. Due to these interactions, the air inside the hole 28 vibrates violently, and the sound from the sound source is quickly attenuated by converting its energy into thermal energy or the like. In this way, the sound absorbing and insulating box 12 quickly absorbs sound from the sound source by exhibiting its sound absorbing performance.

  Next, the main part of the present invention will be described. 4 is an overall perspective view of the sound absorbing and insulating box 12, and FIG. 5 is a cross-sectional view taken along line AA of FIG. Note that the two sound absorbing and insulating boxes 12 arranged at the front and rear portions of the console 11 have the same configuration.

  As shown in FIGS. 4 and 5, the sound absorbing and insulating box 12 is provided with a partition wall 25 that connects the first wall 21 and the second wall 22, so that the first sound absorbing portion 26 a and the second sound absorbing portion that are hollow are formed. It has a portion 26b. In other words, the sound absorbing and insulating box 12 of this embodiment is configured by integrating the first sound absorbing portion 26a having a rectangular box shape and the second sound absorbing portion 26b having a rectangular box shape. Is. A first sound absorbing portion 26 a is formed by a part of the first wall 21 and the second wall 22, the side wall 24, and the partition wall 25, and the other portion of the first wall 21 and the second wall 22 and the side wall 24. A second sound absorbing portion 26 b is formed by the partition wall 25. Further, the partition wall 25 partitions the space 23 inside the sound absorbing and insulating box 12 into two so that their volumes are equal. Accordingly, the small space 23a inside the first sound absorbing portion 26a and the small space 23b inside the second sound absorbing portion 26b have the same volume.

  A part of the first wall 21 serving as a wall material forming the first sound absorbing portion 26a is divided as a first sound absorbing wall 21a. Moreover, it is a wall material which forms the said 1st sound absorption part 26a, and a part of 2nd wall 22 facing the said 1st sound absorption wall 21a is divided as the 1st sound insulation wall 22a. On the other hand, the other part of the first wall 21 serving as a wall material forming the second sound absorbing part 26b is divided as a second sound absorbing wall 21b. Moreover, it is a wall material which forms the said 2nd sound absorption part 26b, and a part of 2nd wall 22 facing the said 2nd sound absorption wall 21b is divided as the 2nd sound insulation wall 22b.

  In the first sound absorbing wall 21a, the plurality of holes 28 are arranged at equal intervals in the vertical direction and the horizontal direction of the first sound absorbing wall 21a. Further, in the second sound absorbing wall 21b, the plurality of holes 28 are arranged at equal intervals in the vertical direction and the horizontal direction of the second sound absorbing wall 21b. As a collection of a plurality of holes 28, the first sound absorbing wall 21a is provided with a first sound absorbing hole 20a, and the second sound absorbing wall 21b is provided with a second sound absorbing hole 20b.

  The hole 28 constituting the second sound absorbing hole 20b has a larger diameter than the hole 28 constituting the first sound absorbing hole 20a, and its opening area is large. The holes 28 constituting the first sound absorbing hole 20a have the same diameter and the same opening area, and the holes 28 constituting the second sound absorbing hole 20b have the same diameter and the same opening area. Furthermore, the opening area S1 of the first sound absorbing hole 20a and the opening area S2 of the second sound absorbing hole 20b, which are the sum of the opening areas of the holes 28, are different from each other. In the present embodiment, the opening area S2 of the second sound absorbing hole 20b is set larger than the opening area S1 of the first sound absorbing hole 20a.

  As described above, the sound absorbing and insulating box 12 exhibits sound absorbing performance by the air inside the hole 28 acting as a mass and the air in the space 23 of the sound absorbing and insulating box 12 acting as a spring. Similarly, in the first and second sound absorbing portions 26a and 26b, the first and second sound absorbing holes 20a and 20b act as masses, and are in the small spaces 23a and 23b of the first and second sound absorbing portions 26a and 26b. The air acts as a spring, thereby exhibiting sound absorption performance.

  Here, the small spaces 23a and 23b have the same volume and the same action as a spring. In contrast, the first and second sound absorbing holes 20a and 20b have different opening areas S1 and opening areas S2, respectively. Accordingly, since the acting mass is different between the first and second sound absorbing parts 26a and 26b, the frequency regions of the sound absorbed by the first and second sound absorbing parts 26a and 26b are different. For this reason, the sound absorption and insulation box 12 has a wide sound absorption region in which the frequency region in which sound can be absorbed by the first sound absorbing unit 26a and the frequency region in which sound can be absorbed by the second sound absorbing unit 26b are combined.

  The opening areas S1 and S2 of the first and second sound absorbing holes 20a and 20b are appropriately set according to the frequency region of the sound absorbed by the sound absorbing and insulating box 12, that is, the frequency region of the sound generated from the sound source. . The first and second sound insulation walls 22a and 22b that do not have the first and second sound absorption holes 20a and 20b are arranged so as to block sound propagating through the console 11 from the front of the vehicle. Therefore, the sound absorbing and insulating box 12 has a sound insulating performance for insulating the sound in addition to the sound absorbing performance for absorbing the sound from the sound source.

Therefore, according to the first embodiment, the following effects can be obtained.
The sound absorbing and insulating box 12 is formed such that the opening areas S1 and S2 of the first and second sound absorbing holes 20a and 20b of the first and second sound absorbing portions 26a and 26b are different from each other. As a result, when various sounds having a wide frequency range pass through the first and second sound absorption holes 20a and 20b, the sound absorption effect based on the Helmholtz resonance principle is exhibited and is quickly absorbed by the sound absorption and insulation box 12. . Therefore, the frequency range of the sound absorbed by the sound absorbing and insulating box 12 can be made wider than that of the conventional configuration, and suitable sound absorbing performance can be exhibited for sounds in a wide frequency range. Therefore, by using the sound absorption and sound insulation box 12 of the present embodiment, the noise level of the vehicle interior noise caused by the sound generated from the drive system parts such as engine sound and gear sound can be reduced as compared with the conventional case. Silence can be achieved.

  -Regarding the first and second sound absorbing portions 26a, 26b, the plurality of holes 28 constituting the first sound absorbing hole 20a have the same diameter and the same opening area, and the plurality of holes constituting the second sound absorbing hole 20b. All 28 have the same diameter and the same opening area. By doing in this way, in the sound absorption and insulation box 12, the frequency region of the sound absorbed for each of the first and second sound absorbing portions 26a and 26b can be clearly set.

  In the sound absorbing and insulating box 12, the wall materials facing the first and second sound absorbing walls 21a and 21b are configured as first and second sound insulating walls 22a and 22b. The first and second sound insulation walls 22a and 22b do not have the hole 28, and are formed so as to shield the space 23 in the sound absorption and insulation box 12 from the outside. For this reason, the propagation of sound through the air can be blocked by the first and second sound insulation walls 22a and 22b, and the sound from the sound source can be prevented from leaking outside. Therefore, it is possible to realize the sound absorbing and insulating box 12 that exhibits excellent sound absorbing and insulating performance against noise having a wide frequency range.

  In the sound absorbing and insulating box 12, the first and second sound absorbing portions 26a and 26b have the same volume, and the opening areas S1 of the first and second sound absorbing holes 20a and 20b with respect to the first and second sound absorbing portions 26a and 26b. , S2 are different from each other. In this case, by changing only the first wall 21 in which the hole 28 is provided in the sound absorbing and insulating box 12, the sound absorbing region of the sound absorbing and insulating box 12 can be easily changed. For this reason, it becomes easy to make it respond | correspond to the frequency region of a sound in order to absorb a sound, and the versatility sound-insulation box 12 can be implement | achieved.

  Since the sound absorbing and insulating box 12 is formed in a thin box shape, the volume occupied by them can be kept small. For this reason, for example, even in a limited space inside the vehicle interior such as the console 11, the installation space for the sound absorbing and insulating box 12 can be easily secured.

  Two sound absorption / insulation boxes 12 are attached to the inside of the console 11, and these are arranged so as to block the course of sound from the drive system components propagating in the console 11. This position is an optimal position for absorbing the sound from the sound source and an optimal position for blocking the sound from the sound source. By attaching the two sound absorbing and insulating boxes 12 at this position, it is possible to effectively absorb and interrupt the sound generated from the drive system components.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. Note that the detailed description of the same parts in the second embodiment as those in the first embodiment is omitted. 6 is an overall perspective view of the sound absorbing and insulating box 32, and FIG. 7 is a cross-sectional view taken along line AA of FIG.

  As shown in FIGS. 6 and 7, the sound absorbing and insulating box 32 includes first and second sound absorbing and insulating sub boxes 32 a and 32 b, and these are integrally assembled. The first and second sound absorption / insulation sub-boxes 32a and 32b have the same internal volume, and a thin sound absorption / insulation box 32 having a thin box shape is formed by joining the side surfaces thereof.

  In the second embodiment, in the sound absorbing and insulating box 32, the first sound absorbing and insulating subbox 32a is configured as the first sound absorbing portion 46a, and the second sound absorbing and insulating subbox 32b is configured as the second sound absorbing portion 46b. That is, the first sound absorbing and insulating sub-box 32a includes a first sound absorbing wall 41a and a first sound insulating wall 42a disposed to face the first sound absorbing wall 41a. A plurality of holes 48 are formed in the first sound absorbing wall 41a, and the holes 48 are arranged at equal intervals in the vertical direction and the horizontal direction of the first sound absorbing wall 41a. And the aggregate | assembly of the hole 48 penetrated by the 1st sound absorption wall 41a is comprised as the 1st sound absorption hole 40a.

  On the other hand, the second sound absorbing and insulating sub-box 32b includes a second sound absorbing wall 41b and a second sound insulating wall 42b disposed to face the second sound absorbing wall 41b. The second sound absorbing wall 41b is provided with a plurality of holes 49 larger in diameter than the holes 48 constituting the first sound absorbing holes 40a, and each hole 49 has a vertical direction and a horizontal direction of the second sound absorbing wall 41b. Are arranged at equal intervals. And the aggregate | assembly of the hole 49 penetrated by the 2nd sound absorption wall 41b is comprised as the 2nd sound absorption hole 40b.

  In the case of this embodiment, similarly to the first embodiment, the first and second sound absorbing portions 46a and 46b have the same volume, and the opening areas S1 and S2 of the first and second sound absorbing holes 40a and 40b are different from each other. As a result, the sound absorption and insulation box 32 has a wide sound absorption region.

Therefore, according to the second embodiment, the following effects can be obtained.
The sound absorbing and insulating box 32 is configured by integrally assembling a first sound absorbing and insulating subbox 32a having a first sound absorbing hole 40a and a second sound absorbing and insulating subbox 32b having a second sound absorbing hole 40b. . In this case, by optimizing the combination of the sound absorption and insulation sub-boxes having different sound absorption regions, more suitable sound absorption performance can be exhibited for sounds having a wide range of frequencies.

In addition, you may change the said embodiment as follows.
In each embodiment, the sound absorbing and insulating box 12 is not limited to providing two sound absorbing parts, and three or more sound absorbing parts may be provided. For example, in the first embodiment, three or more kinds of sound absorbing holes having different opening areas may be provided in the first wall 21 and the portions corresponding to the sound absorbing holes may be used as sound absorbing portions. If it is 2nd Embodiment, what is necessary is just to comprise the sound absorption sound insulation box 32 from three or more sound absorption sound insulation sub-boxes.

  -In 1st Embodiment, although the sound-absorption sound-insulation structure was comprised from the two sound-absorption sound insulation boxes 12, you may set the number arbitrarily as needed. Also in the second embodiment, the sound absorbing and insulating structure may be configured from a sound absorbing and insulating box whose number is arbitrarily set as necessary.

  -In each embodiment, the attachment position of the sound-insulation box 12 and 32 is arbitrarily set according to the position of a sound source, the shape of to-be-attached components, etc. For example, the sound absorbing and insulating box 12 may be attached to the inner wall surfaces of the both side walls 11 a of the console 11.

  -In 1st Embodiment, if the hole 28 which comprises the 1st and 2nd sound absorption holes 20a and 20b is on the 1st and 2nd sound absorption walls 21a and 21b, respectively, it sets to arbitrary (random) positions. Also good. Further, the first and second sound absorbing holes 20a and 20b do not necessarily have to be formed from holes having the same diameter, and may be formed from holes having different opening areas.

-In 1st Embodiment, the position of the hole 28 which comprises the 1st and 2nd sound absorption holes 20a and 20b may not be at equal intervals in the vertical direction and the horizontal direction of the sound absorption and insulation box 12, respectively.
-In each embodiment, although the volume of the 1st and 2nd sound absorption part was made the same, you may vary a volume for every sound absorption part.

  In the second embodiment, the sound absorbing and insulating box 32 may be configured by forming a plurality of the sound absorbing and insulating boxes 12 of the first embodiment and assembling them together. Alternatively, the sound absorbing and insulating box 32 may be configured by being assembled separately to a console or the like, without necessarily being assembled integrally with the sound absorbing and insulating box 32.

  -In each embodiment, although all the holes which comprise a sound absorption hole had circular shape, arbitrary shapes, such as an ellipse shape and a polygon, may be sufficient, for example. In this case, examples of the polygon include a triangle and a rhombus.

  In each embodiment, the sound absorbing and insulating boxes 12 and 32 are both formed in a thin box shape, but may be changed to any shape in consideration of the sound absorbing performance, the mounting position, and the like. In this case, examples of the changeable shape include a sphere, a disk, and a trapezoid.

  -In each embodiment, you may attach the sound-insulation box 12 and 32 to vehicle interior parts other than the console 11, for example, an instrument panel, a glove box, a door trim, a rear trim, a roof trim, a pillar trim, etc. Further, in these cases, it may be used as a component that absorbs in-vehicle noise due to audio or human voice other than vehicle drive system components.

-In each embodiment, as long as the opening area of a sound absorption hole differs for every sound absorption part, a sound absorption hole may be comprised from one hole.
Next, the technical idea that can be grasped from the embodiment and other examples will be described below.

The sound absorbing structure according to any one of claims 1 to 3, comprising a plurality of the sound absorbing bodies.
The sound absorbing structure according to any one of claims 1 to 3, wherein the internal volume of each of the sound absorbing portions is the same.

The sound absorbing structure according to any one of claims 1 to 3, wherein the sound absorbing body is formed in a thin box shape.
-Vehicle interior parts provided with the sound absorption structure of any one of Claims 1-3.

The perspective view in a vehicle interior which shows the attachment position of the sound absorption and sound insulation box in 1st Embodiment. The schematic cross section at the time of seeing the console which similarly shows the attachment position of a sound-insulation sound box from upper direction. The schematic sectional drawing at the time of seeing the console which similarly shows the attachment position of a sound-insulation sound box from the side. The perspective view of a sound absorption sound insulation box similarly. AA sectional drawing of FIG. The perspective view of the sound-absorption sound insulation box in 2nd Embodiment. AA sectional drawing of FIG.

Explanation of symbols

  12, 32 ... Sound absorbing and insulating box as sound absorbing body, 20a, 40a ... First sound absorbing hole as sound absorbing hole, 20b, 40b ... Second sound absorbing hole as sound absorbing hole, 21a, 41a ... First sound absorbing wall as a sound absorbing wall, 21b, 41b ... Second sound absorbing wall as a sound absorbing wall, 22a, 42a ... First sound insulating wall as a sound insulating wall, 22b, 42b ... Second sound insulating wall as a sound insulating wall, 28, 48, 49 ... hole, 26a, 46a ... first sound absorbing part as sound absorbing part, 26b, 46b ... second sound absorbing part as sound absorbing part.

Claims (4)

A sound-absorbing structure that absorbs sound in a predetermined frequency range generated from a sound source,
A sound absorbing body having a plurality of sound absorbing portions forming a hollow shape is provided, and among the wall materials constituting each sound absorbing portion, each of the wall materials arranged toward the sound source is a sound absorbing wall, and one or more A sound-absorbing structure characterized in that a sound-absorbing hole made of the hole is provided in each sound-absorbing wall by making the holes transparent, and the opening area of the sound-absorbing hole is made different for each sound-absorbing part.   The sound absorbing structure according to claim 1, wherein each of the plurality of holes constituting the sound absorbing hole has the same opening area.   The sound absorbing structure according to claim 1 or 2, wherein a wall material facing the sound absorbing wall is configured as a sound insulating wall not having the sound absorbing hole. A sound absorbing and insulating structure that absorbs sound in a predetermined frequency region generated from a sound source,
A sound absorbing body having a plurality of sound absorbing portions forming a hollow shape is provided, and among the wall materials constituting each sound absorbing portion, each of the wall materials arranged toward the sound source is a sound absorbing wall, and one or more By making the holes transparent, each sound absorbing wall is provided with a sound absorbing hole made of the hole, and the sound absorbing hole has a different opening area for each sound absorbing portion, and a wall material on the side facing the sound absorbing wall is provided. A sound-absorbing / insulating structure characterized in that the sound-absorbing wall has no sound-absorbing holes.

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