Noise reduction structure

Abstract

To provide a noise reduction structure capable of reducing the noise of both the inside and the outside of a building.SOLUTION: A noise reduction structure 20 comprises slopes 34, 46 sloping so as to extend from a window surface toward a tip of a veranda 12 while provided at at least one of a ceiling surface and a lateral wall surface of the veranda 12 at a building 10 and a sound absorption mechanism provided at the slopes 34, 46 and capable of absorbing noise.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a noise reduction structure. [Background technology]

[0002] The following Patent Document 1 describes a sound-insulating balcony structure that has a reflective surface on the balcony ceiling that reflects incident noise sound waves. In this sound-insulating balcony structure, the inclination angle of the reflective surface relative to the propagation direction of the direct noise waves is set to 90 degrees or more, thereby reducing noise incident on the window openings of the building. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-211509 Summary of the Invention [Problem to be solved by the invention]

[0004] The sound-insulating veranda structure in Patent Document 1 reflects noise to the outside of the building. Therefore, even if it is possible to reduce noise inside the building, it is difficult to reduce noise outside the building. This means that the reflected noise may affect other buildings.

[0005] In consideration of the above, an object of the present invention is to provide a noise reduction structure that can reduce noise both inside and outside a building. [Means for solving the problem]

[0006] The noise reduction structure of claim 1 is a structure for reducing noise generated by a veranda ceiling in a building. At the tip of the horizontal section that forms A sloped portion that is provided and slopes so as to widen from the window surface toward the tip of the balcony Or, an inclined portion provided at the tip of a vertical portion forming a side wall surface of the balcony in the building and inclined so as to widen from the window surface toward the tip of the balcony; The inclination To the department and a sound absorbing mechanism that is provided to absorb noise.

[0007] In the noise reduction structure of claim 1, a sound-absorbing mechanism that absorbs noise is provided on a sloped portion provided on at least one of the balcony ceiling and side wall surfaces. If the sound-absorbing mechanism is located on the sloped portion of the balcony ceiling, it can absorb noise from below. Also, if the sound-absorbing mechanism is located on the sloped portion of the balcony side wall, it can absorb noise from the side.

[0008] This reduces noise both inside and outside the building compared to structures that use a "reflective surface" on the balcony ceiling to reflect noise.

[0009] Furthermore, by installing the sound-absorbing mechanism on the sloped portion of the balcony ceiling or side wall surface rather than directly on the balcony ceiling or side wall surface, the sound-absorbing area of ​​the sound-absorbing mechanism is increased, enabling high sound-absorbing performance.

[0010] Furthermore, the sloped portion is inclined so as to widen from the window surface toward the end of the balcony, so it is unlikely to obstruct the view from inside the room or obstruct the entry of light.

[0011] The noise reduction structure of claim 2 is as follows: Balcony on a building Installed on both the ceiling and side walls The balcony also has an inclined portion that slopes from the window surface toward the tip of the balcony, and a sound-absorbing mechanism that is provided on the inclined portion and can absorb noise.

[0012] In the noise reduction structure of claim 2, since the inclined portions are provided on both the ceiling surface and the side wall surface, noise incident from both below and the sides can be absorbed, thereby improving sound absorption performance compared to when the inclined portions are provided on only one of the ceiling surface and the side wall surface.

[0013] A noise reduction structure according to claim 3 is the noise reduction structure according to claim 1 or 2, wherein the sound absorbing mechanism is formed of at least one of a punched metal and a porous material.

[0014] In the noise reduction structure of claim 3, the sound absorbing mechanism is formed from at least one of punched metal and porous material. Therefore, even if the sound absorbing mechanism is exposed to wind and rain, rainwater is less likely to accumulate and is easily drained. This makes the sound absorbing mechanism less likely to deteriorate. [Effects of the Invention]

[0015] The present invention can reduce noise both inside and outside a building. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1A is a side cross-sectional view showing a noise reduction structure according to an embodiment, and FIG. 1B is a cross-sectional view taken along line BB in FIG. [Figure 2] (A) is a partially enlarged cross-sectional view showing an example in which a punched metal is used as a sound-absorbing mechanism, (B) is a partially enlarged cross-sectional view showing an example in which a porous material is used as a sound-absorbing mechanism, and (C) is a partially enlarged cross-sectional view showing an example in which a punched metal and a porous material are used as a sound-absorbing mechanism. [Figure 3] FIG. 1A is a side cross-sectional view showing a modification of the noise reduction structure according to the embodiment, and FIG. 1B is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 10(A) is a side cross-sectional view showing another modified example of the noise reduction structure according to the embodiment, and FIG. 10(B) is a cross-sectional view taken along line BB in FIG. [Figure 5] 1A is a partially enlarged cross-sectional view showing a modified example of the arrangement of the sound-absorbing mechanism, FIG. 1B is a partially enlarged cross-sectional view showing another modified example, and FIG. 1C is a partially enlarged cross-sectional view showing yet another modified example. [Figure 6] 1A is a side cross-sectional view showing a modified example in which an acoustic tube is used as a sound absorbing mechanism, and FIG. 1B is a side cross-sectional view showing variations in the arrangement of the acoustic tube. [Figure 7] (A) is a cross-sectional view showing the configuration of the acoustic tube, and (B) is a graph showing the mechanism of the sound absorption effect of the acoustic tube. [Figure 8] 1 is a front view showing a noise reduction structure according to an embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, a noise reduction structure according to an embodiment of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in the various drawings are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and may be present in multiple numbers.

[0018] Furthermore, the description of the same components and symbols in each drawing may be omitted. Note that the present invention is not limited to the following embodiments, and may be implemented by making appropriate modifications, such as omitting components or replacing them with different components, within the scope of the object of the present invention.

[0019] In each figure, the directions indicated by arrows X and Y are directions along the horizontal plane and are perpendicular to each other. The direction indicated by arrow Z is a direction along the vertical direction (up and down). In each figure, the directions indicated by arrows X, Y, and Z are assumed to be consistent with each other.

[0020] <Noise reduction structure> 1(A) and 1(B) show a noise reduction structure 20 according to an embodiment of the present invention. The noise reduction structure 20 is applied to a building 10 and is a noise reduction means intended to suppress noise both inside and outside the building 10. The noise reduction structure 20 is configured to include a ceiling member 30, a partition member 40, and a perforated metal 50 as a sound absorbing mechanism, which will be described later.

[0021] (building) Although the use of the building 10 is not particularly limited, the building 10 in this embodiment is an apartment building. The noise reduction structure 20 is applied to a balcony 12 of the building 10.

[0022] An arterial road (not shown, such as a national expressway, a national highway, or a prefectural road) runs in front of the balcony 12 of the building 10. The longitudinal direction (X direction) of the balcony 12 is arranged along the direction of the lanes on the arterial road. Note that the area in front of the building 10 does not necessarily have to be an arterial road; for example, various roads other than arterial roads, train tracks, etc. may run.

[0023] The balcony 12 is an outdoor space separated from the indoor space R of the building 10 by a glass window 14. The glass window 14 is a sliding window that allows access from the indoor space R to the balcony 12, and is arranged along the longitudinal direction of the balcony 12. A slab 16 is formed on the outside of the glass window 14.

[0024] The slab 16 is a cantilevered slab that protrudes outward from the building 10, and is provided on each floor of the building 10 to form the floor surface of the veranda 12 on each floor. A handrail 16A is provided at the tip of the slab 16.

[0025] In this embodiment, an example is shown in which building 10 has two dwelling units arranged in the part facing the main road, but the number of dwelling units arranged in the part facing the main road is not particularly limited.

[0026] (ceiling components) As shown in Figure 1(A), in the balcony 12, a ceiling member 30 is provided below the slab 16 that forms the floor surface of the upper floor. This ceiling member 30 has a horizontal portion 32 and an inclined portion 34. The horizontal portion 32 and the inclined portion 34 are each formed using a non-combustible board material such as a calcium silicate board.

[0027] The horizontal section 32 is a section formed in the horizontal direction below the slab 16, and is disposed on the outer wall surface side of the building 10. On the other hand, the inclined section 34 is a section formed below the slab 16 and inclined upward relative to the horizontal section 32, and is disposed from the tip of the horizontal section 10 to the tip of the slab 16. The inclined section 34 is inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12. The inclined section 34 may also be curved.

[0028] The lower surfaces of the horizontal portion 32 and the inclined portion 34 form the ceiling surface of the balcony 12. The inclined portion 34 is an example of the "inclined portion provided on the ceiling surface of the balcony" in the present invention.

[0029] A space V1 formed between the slab 16 forming the floor surface of the upper floor and the ceiling member 30 can be used as a space for installing equipment and piping.

[0030] It is preferable that the horizontal portion 32 and the inclined portion 34 are fixed to a base material made of a metal material such as aluminum or steel, or fitted into a frame, etc. This ensures that the ceiling member 30 is rigid enough to prevent deformation or scattering when blown by the wind.

[0031] (Partition plate member) As shown in Figure 1(B), the balcony 12 is divided by partition members 40. The partition members 40 are installed at the boundaries between adjacent dwelling units, dividing the balcony 12 into multiple exclusive use areas and forming the side walls of these exclusive use areas. An "exclusive use area" is an area that is used daily only by the residents of a single dwelling unit.

[0032] The partition member 40 has two vertical portions 42 and 44 and an inclined portion 46. The vertical portions 42, 44 and the inclined portion 46 are each formed using a non-combustible plate material such as a calcium silicate board or a flexible board.

[0033] The vertical portion 42 is a portion formed along the vertical direction between the upper and lower slabs 16, and is disposed on the outer wall surface side of the building 10. The vertical portion 42 is also disposed along the short side direction (Y direction) of the balcony 12, and is longer in the Y direction than the vertical portion 44.

[0034] Similar to the vertical section 42, the vertical section 44 is a section formed along the vertical direction between the upper and lower slabs 16, and is disposed on the outer wall surface side of the building 10. The vertical section 44 is spaced apart from the vertical section 42 in the longitudinal direction of the balcony 12 and is disposed parallel to the vertical section 42.

[0035] The inclined portion 46 is a portion that connects the tip of the vertical portion 42 and the tip of the vertical portion 44. The inclined portion 46 is a portion formed between the upper and lower slabs 16, inclined toward the outside of the glass window 14 with respect to the connected vertical portion 44 (in other words, a portion that inclines with respect to the vertical portion 44 so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12). The inclined portion 46 may also be curved.

[0036] The vertical portions 42, 44 and the inclined portion 46 form the side wall surface of the exclusive use portion of the balcony 12. The inclined portion 46 is an example of the "inclined portion provided on the side wall surface of the balcony" in the present invention. The space V2 formed between the vertical portions 42, 44 and the inclined portion 46 can be used as a space for installing equipment and piping.

[0037] It is preferable that the vertical portions 42, 44 and the inclined portion 46 are fixed to a base material made of a metal material such as aluminum or steel, or are fitted into a four-sided frame, etc. This ensures that the partition member 40 has sufficient rigidity to prevent deformation or scattering when blown by the wind.

[0038] As shown in FIG. 8, the upper end of the inclined portion 46 of the partition member 40 is joined to the lateral end of the inclined portion 34 of the ceiling member 30.

[0039] In other words, when viewing the balcony 12 from the front (along the Y direction), the inclined portions 46 and 34 form a gate-shaped frame that surrounds the glass window 14 on three sides (the glass window 14 on the "left side" of the paper in Figure 8).

[0040] The inclined portion 46 and the inclined portion 34 form an L-shaped frame that surrounds the glass window 14 on two sides (the glass window 14 on the "right" side of the paper in FIG. 8).

[0041] (sound absorbing mechanism) 1(A) and 8, a perforated metal 50 is provided on the surface of the inclined portion 34 of the ceiling member 30. The perforated metal 50 is an example of a sound absorbing mechanism of the present invention.

[0042] 1(B) and 8, the perforated metal 50 is also provided on the surface of the inclined portion 46 of the partition member 40. Furthermore, the perforated metal 50 covers substantially the entire surface of the inclined portions 34 and 46.

[0043] 2(A), the perforated metal 50 is a steel or aluminum plate material in which a plurality of through holes 52 are formed at predetermined intervals in the in-plane direction. The perforated metal 50 is fixed to the surfaces of the inclined portions 34 and 46 using appropriate fixing means such as bolts or adhesive.

[0044] The sound absorbing mechanism of the present invention may be a porous material 54 shown in Fig. 2(B). For example, foamed polypropylene having voids may be used as the porous material 54. Alternatively, urethane or the like may be used as the porous material 54.

[0045] The sound-absorbing mechanism of the present invention can also be a combination of a perforated metal 50 and a porous material 54, as shown in Figure 2(C). The specifications of these sound-absorbing mechanisms may be changed depending on the location where they are applied. For example, the perforated metal 50 may be used for the inclined portion 34, and the porous material 54 may be used for the inclined portion 46.

[0046] The "sound absorbing" performance of the sound absorbing mechanism of the present invention refers to the ability to absorb (deade) at least a portion of incident sound. Incident sound that is not absorbed may be reflected to the outside.

[0047] To achieve this sound absorption performance, the sound absorbing mechanism has holes (through holes 52 in the punched metal 50 or air bubbles in the porous material 54) for absorbing incident sound. On the other hand, the "reflective surface" that is not a sound absorbing mechanism is, for example, a smooth and hard surface made of a heavy material such as a metal material.

[0048] <Action and effect> In the noise reduction structure 20 according to an embodiment of the present invention, as shown in Figures 1(A) and (B), a sound-absorbing mechanism for absorbing noise is provided on an inclined portion provided on at least one of the ceiling surface and side wall surface of the balcony 12.

[0049] Specifically, a punched metal 50 serving as a sound-absorbing mechanism is provided on the inclined portion 34 of the ceiling member 30 that forms the ceiling surface of the balcony 12, and a punched metal 50 is provided on the inclined portion 46 of the partition member 40 that forms the side wall surface of the balcony 12.

[0050] By providing the sound-absorbing mechanism on the sloped portion 34 of the ceiling surface of the balcony 12, it is possible to absorb noise from below as indicated by arrow N1 in Figure 1(A). In particular, on the upper floors of the building 10, noise emitted from vehicles traveling on the road in front, which is the main noise source, enters from below. By providing a sound-absorbing surface or sound-absorbing mechanism on the ceiling surface, this type of noise can be efficiently reduced.

[0051] Furthermore, since the sound-absorbing mechanism is located on the sloped portion 46 of the side wall surface of the balcony 12, it is possible to absorb noise from the side as indicated by arrow N2 in Figure 1(B). For example, the angle of the noise incident on the side wall surface changes as a vehicle travels on the road in front of the building 10, but the noise can be reduced regardless of the change in the angle of incidence.

[0052] This reduces noise both inside and outside the building 10 compared to a structure that reflects noise by providing a "reflective surface" on the ceiling or side wall of the balcony 12. In contrast, if a "reflective surface" is provided on the ceiling or side wall of the balcony 12, most of the noise is reflected outside the building 10, making it difficult to reduce noise outside the building 10.

[0053] Furthermore, by providing sound absorbing mechanisms on the inclined portions 34 and 46, reflected sound is suppressed, which in turn suppresses the incidence of rubbing reflected sound on the glass window 14. This makes it possible to suppress a decrease in sound insulation due to the coincidence effect between the glass and the rubbing incident sound.

[0054] Furthermore, by providing the perforated metal 50 as a sound absorbing mechanism on the inclined portions 34 and 46 of the ceiling and side walls of the balcony 12 rather than providing the sound absorbing mechanism directly on the ceiling and side walls of the balcony 12, the sound absorbing area of ​​the perforated metal 50 is increased, thereby achieving high sound absorbing performance.

[0055] That is, the area of ​​the inclined portion 34 is larger than the area of ​​region M shown in FIG. 1(A). Region M is the horizontal projection of the inclined portion 34 onto the slab 16, and the area of ​​region M is the horizontal projection area of ​​the inclined portion 34. Although the inclined portion 34 and region M require the same area in terms of floor plan, the actual area of ​​the inclined portion 34 is larger. Therefore, the area in which the perforated metal 50 can be installed is larger in the inclined portion 34, and it is easier to demonstrate sound absorption performance. The same is true for the inclined portion 46. That is, by providing sound-absorbing mechanisms in the inclined portions 34 and 46, noise can be reduced over a wider range of incident angles.

[0056] Furthermore, since the inclined portion 34 is inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12 (in other words, the tip of the slab 16), it is easy to absorb noise from the front as shown by arrow N3 in Figure 1(A). Similarly, the inclined portion 46 is inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12, so it can also absorb noise from the front as shown by arrow N4 in Figure 1(B).

[0057] Furthermore, these inclined portions 34 and 46 are inclined so as to widen from the window surface of the glass window 14 toward the tip of the balcony 12, so that they are unlikely to obstruct the view from the indoor space R or obstruct the entry of light. Furthermore, when the balcony 12 is viewed from the front, the inclined portions 34 and 46 are inclined so as to recede toward the glass window 14, so that the feeling of oppression from the building 10 can be reduced.

[0058] In the noise reduction structure 20 according to the embodiment of the present invention, the sound absorbing mechanism is formed of at least one of a perforated metal 50 and a porous material 54. Specifically, the sound absorbing mechanism is formed of a perforated metal 50 shown in Fig. 2(A), a porous material 54 shown in Fig. 2(B), or a composite of the perforated metal 50 and a porous material 54 shown in Fig. 2(C).

[0059] Therefore, even if the sound absorbing mechanism is exposed to wind and rain, rainwater is less likely to accumulate and is easily drained, making the sound absorbing mechanism less likely to deteriorate.

[0060] <Modification> (Modifications regarding the placement of sound absorbing mechanisms) 1(A) and 1(B), in the noise reduction structure 20 according to this embodiment, perforated metal 50 as a sound-absorbing mechanism is provided on both the inclined portions 34 and 46 formed on the ceiling surface and the side wall surface of the balcony 12, but the embodiment of the present invention is not limited to this. For example, a configuration may be adopted in which a sound-absorbing mechanism is not provided on either the inclined portions 34 or 46.

[0061] 3(A) and 3(B), the partition member may be formed only by the vertical portion 42, and a perforated metal 50 serving as a sound-absorbing mechanism may be provided on the inclined portion 34 formed on the ceiling surface of the balcony 12. The sound-absorbing mechanism may or may not be provided on the vertical portion 42. Furthermore, the balcony 12 may not be provided with a partition member. A configuration without a partition member can be applied to buildings such as hospitals and public buildings.

[0062] 4(A) and 4(B), the ceiling member 30 (see FIG. 1) may be omitted, and a perforated metal 50 serving as a sound-absorbing mechanism may be provided on an inclined portion 46 formed on the side wall surface of the balcony 12. A sound-absorbing mechanism may or may not be provided on the underside of the slab 16.

[0063] In other words, in the present invention, it is sufficient that an inclined portion (i.e., at least one of inclined portions 34 and 46) is provided on at least one of the ceiling surface and side wall surface of the balcony 12, and that a sound-absorbing mechanism is provided on at least one of these inclined portions 34 and 46.

[0064] In this case, the sound absorbing mechanism may be provided on a part of the inclined portion 46, as in the perforated metal 50 shown in Fig. 5(A). The sound absorbing mechanism may also be disposed in a position that includes the vertical portion 44, as in the perforated metal 50 shown in Fig. 5(B). The sound absorbing mechanism fixed to the vertical portion 44 may cover a part of the vertical portion 44, as shown in Fig. 5(C).

[0065] It should be noted that the various modifications regarding the placement of these sound absorbing mechanisms can also be applied to the placement of the acoustic tube 60, which will be described later.

[0066] (Variations regarding the specifications of the sound absorbing mechanism) In the noise reduction structure 20 according to this embodiment, as explained using Figures 2(A) to (C), the sound absorbing mechanism is formed by at least one of the punched metal 50 and the porous material 54, but the embodiment of the present invention is not limited to this.

[0067] For example, the sound absorbing mechanism can be formed using an acoustic tube 60, as shown in Figures 6(A) and (B). The acoustic tube 60 is a cylindrical tube with a bottom, as shown in Figure 7(A). Noise incident on the acoustic tube 60, as indicated by arrow N5, is reflected by the bottom 62 of the acoustic tube 60 and is emitted from the acoustic tube 60, as indicated by arrow N6.

[0068] 7(B) shows the waveforms of the incident and reflected sound waves of wavelength λ measured at the open end of the acoustic tube 60, as shown by curves K1 and K2. The incident and reflected sound waves of wavelength λ are out of phase with each other by half the wavelength (0.5λ) at the open end of the acoustic tube 60, so they interfere with each other, resulting in a sound absorption effect.

[0069] Because the length L of the acoustic tube 60 is (0.25λ), the incident and reflected sound waves of wavelength λ are shifted in phase by half the wavelength (0.5λ) at the open end of the acoustic tube 60. In other words, noise of various wavelengths enters the acoustic tube 60, but of the noise, noise whose length equivalent to 0.25 times the wavelength λ matches the length L of the acoustic tube 60 is absorbed.

[0070] 6(A), the sound absorbing mechanism of this embodiment uses a combination of multiple acoustic tubes 60 of different lengths. Specifically, each acoustic tube 60 is arranged with its open end facing downward and its cylindrical axis aligned in the vertical direction.

[0071] Furthermore, the length of the acoustic tube 60 arranged at the tip of the balcony 12 is shorter than the length of the acoustic tube 60 arranged at a position on the balcony 12 close to the glass window 14.

[0072] As a result, the acoustic tube 60 located closer to the glass window 14 absorbs noise with a relatively long wavelength (low sound), while the acoustic tube 60 located at the tip of the balcony 12 absorbs noise with a short wavelength (high sound). The length of the acoustic tube 60 can be varied as needed depending on the wavelength of the noise to be absorbed.

[0073] The acoustic tubes 60 can also be arranged as shown in Figure 6(B). In the example shown in this figure, each acoustic tube 60 is arranged with its open end facing the tip of the balcony 12 and its cylindrical axis running horizontally (from the glass window 14 toward the tip of the balcony 12).

[0074] Furthermore, the length of the acoustic tubes 60 arranged at the lower part of the balcony 12 is shorter than the length of the acoustic tubes 60 arranged at a position close to the slab 16 above.

[0075] As a result, the acoustic tube 60 located closer to the slab 16 can absorb noise with a relatively long wavelength (low sound), while the acoustic tube 60 located below can absorb noise with a relatively short wavelength (high sound).

[0076] In this way, the "inclined portion provided on the ceiling surface of the balcony and sloping so as to widen from the window surface toward the tip of the balcony" in this invention also includes an inclined portion formed by the open ends of multiple acoustic tubes 60 of different lengths.

[0077] Although not shown in the figures, the acoustic tube 60 may be provided on the side wall surface of the balcony 12 in addition to or instead of the ceiling surface of the balcony 12. In this case, too, the open end of the acoustic tube 60 is positioned so as to form a sloped portion that widens from the glass window 14 toward the tip of the balcony 12.

[0078] As described above, the sound-absorbing mechanism of the present invention is not particularly limited in configuration as long as it absorbs noise, and for example, various perforated plates other than the punched metal 50 can be used as resonators. Also, the sound-absorbing mechanism may be a sound-absorbing plate that absorbs sound by vibrating in accordance with the frequency of the incident noise. [Explanation of symbols]

[0079] 10 Building 12 Veranda 14 Glass window (window) 30 Ceiling material (ceiling) 34 Slope 40 Partition plate member (side wall) 46 Slope 50 Punching metal (sound absorbing mechanism) 54 Porous material (sound absorption mechanism) 60 Acoustic tube (sound absorbing mechanism)

Claims

1. an inclined portion provided at the tip of a horizontal portion forming the ceiling surface of a balcony in the building and inclined so as to widen from the window surface toward the tip of the balcony, or an inclined portion provided at the tip of a vertical portion forming the side wall surface of the balcony in the building and inclined so as to widen from the window surface toward the tip of the balcony; a sound absorbing mechanism provided on the inclined portion and capable of absorbing noise; Noise reduction structure.

2. an inclined portion provided on both the ceiling surface and the side wall surface of the balcony in the building, and inclined so as to widen from the window surface toward the tip of the balcony; a sound absorbing mechanism provided on the inclined portion and capable of absorbing noise; Noise reduction structure.

3. 3. The noise reduction structure according to claim 1, wherein the sound absorbing mechanism is formed of at least one of a punched metal and a porous material.

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