Anechoic chamber, ceiling structure of an anechoic chamber, and acoustic testing method

Abstract

Reduce factors that cause sound reflection. [Solution] The anechoic chamber 1 comprises a ceiling structure 2 including a plurality of ceiling sound-absorbing wedges 21 arranged in two dimensions and a sound-absorbing wedge insertion frame 22 that holds the plurality of ceiling sound-absorbing wedges 21, and a floor structure 3 including a plurality of floor sound-absorbing wedges 31 arranged in two dimensions, a plurality of mesh floors 33 that can be arranged in two dimensions between the ends of the floor sound-absorbing wedges 31 and the ends of the ceiling sound-absorbing wedges 21, and a support member 34 that supports the mesh floors 33. The ceiling structure 2 includes suspension wires 81 attached to the sound-absorbing wedge insertion frame 22 for positioning acoustic equipment 91 between the ceiling structure 2 and the floor structure 3. The floor structure 3 is switchable between an initial state T1 in which a plurality of mesh floors 33 are positioned between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21, and a test-start ready state T2 in which no plurality of mesh floors 33 are positioned between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21.

Description

Technical Field

[0001] The present invention relates to an anechoic chamber, a ceiling structure of the anechoic chamber, and an acoustic test method.

Background Art

[0002] Equipment that suppresses the generation of electromagnetic wave and sound reflections to a degree where it can be considered that there is no reflection is known. Equipment that focuses on electromagnetic waves is called an anechoic chamber for radio waves. Equipment that focuses on sound reflection is called an anechoic chamber. An anechoic chamber is used when conducting various tests related to sound. For example, an anechoic chamber may be used when testing a prototype during the development of acoustic devices such as speakers and microphones. Patent Document 1 discloses a floor member disposed in an anechoic chamber. Patent Document 2 discloses an anechoic chamber for radio waves provided with a hanging type lifting and moving plate that can move in the vertical direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, an anechoic chamber is required to suppress sound reflections to a degree where it can be substantially considered that there is no reflection. Sound-absorbing wedges made of soft materials such as glass wool are laid on the ceiling, walls, and floor of the anechoic chamber, and these sound-absorbing wedges suppress sound reflections. On the other hand, auxiliary members such as the floor member described in Patent Document 1 for working in the anechoic chamber are arranged in the interior of the anechoic chamber. These members can be a factor in generating slight sound reflections.

[0005] This invention provides an anechoic chamber, a ceiling structure for an anechoic chamber, and an acoustic testing method that can reduce factors that cause sound reflection. [Means for solving the problem]

[0006] An anechoic chamber according to one embodiment of the present invention comprises a ceiling structure including a plurality of ceiling sound absorbers arranged in a two-dimensional manner and a ceiling grid member that holds the plurality of ceiling sound absorbers, and a floor structure including a plurality of floor sound absorbers arranged in a two-dimensional manner, a plurality of floor members that can be arranged in a two-dimensional manner between the ends of the floor sound absorbers and the ends of the ceiling sound absorbers, and column members that support the floor members, wherein the ceiling structure includes a suspension part attached to the ceiling grid member for arranging an object to be suspended between the ceiling structure and the floor structure, and the floor structure is switchable between a first embodiment in which a plurality of floor members are arranged between the floor sound absorbers and the ceiling sound absorbers, and a second embodiment in which no plurality of floor members are arranged between the floor sound absorbers and the ceiling sound absorbers.

[0007] This anechoic chamber allows for the suspension of an object to be attached to the ceiling grid members of the ceiling structure and positioned between the ceiling sound absorber and the floor sound absorber. This positioning work involves an operator entering the anechoic chamber and placing the object in the designated position. However, by using the first configuration, in which multiple floor members are placed between the floor sound absorber and the ceiling sound absorber, it is possible to perform the work inside the anechoic chamber. Furthermore, during testing, since the object is suspended from the ceiling grid members of the ceiling structure, there is no need to support it from the floor. As a result, the second configuration, in which multiple floor members are not placed between the floor sound absorber and the ceiling sound absorber, can be used during testing. Therefore, testing can be performed without floor members that could cause sound reflection.

[0008] In the anechoic chamber described above, the column members include floor member support sections on which floor members are placed. When the floor structure is in its first form, the floor member support sections are located between the floor sound absorber and the ceiling sound absorber. When the floor structure is in its second form, the floor member support sections may be located between the front and base ends of the floor sound absorber. This configuration makes it possible to suppress sound reflection caused by the floor member support sections.

[0009] In the anechoic chamber described above, the suspension section may include a position adjustment section for adjusting the distance from the tip of the ceiling sound absorber to the object to be suspended, or from the tip of the floor sound absorber to the object to be suspended. With this configuration, the object to be suspended can be placed at a desired position within the anechoic chamber.

[0010] In the anechoic chamber described above, the suspended object is a lighting fixture placed between the ceiling structure and the floor structure. When the floor structure is in its first form, the lighting fixture is placed between the floor sound absorber and the ceiling sound absorber. When the floor structure is in its second form, the lighting fixture does not need to be placed between the front and base ends of the floor sound absorber. With this configuration, when the object is placed inside the anechoic chamber, the lighting fixture can brighten the interior of the anechoic chamber, making it easier to work inside the chamber. Furthermore, when conducting tests, it is possible to ensure that there are no lighting fixtures inside the anechoic chamber that could cause sound reflection. Therefore, factors that cause sound reflection can be reduced.

[0011] The above-described anechoic chamber may further include a ceiling-side structural element, and the ceiling lattice member may be connected to the ceiling-side structural element by a suspension support. With this configuration, a predetermined working space can be provided between the ceiling-side structural element and the ceiling lattice member.

[0012] The above-described anechoic chamber may further include a wall structure comprising a plurality of sound-absorbing wall elements arranged in a two-dimensional manner, and a wall grid member that holds the plurality of sound-absorbing wall elements. This configuration makes it possible to suppress the occurrence of sound reflections on the wall side of the anechoic chamber.

[0013] In the anechoic chamber described above, the ceiling lattice member includes multiple ceiling lattice sections into which each of the multiple ceiling sound absorbers is inserted, and the wall lattice member includes multiple wall lattice sections into which each of the multiple wall sound absorbers is inserted. The size of the ceiling lattice section may be smaller than the size of the wall lattice section. With this configuration, the ceiling sound absorbers placed in the ceiling lattice section, which are subjected to a vertically downward force along the direction in which the ceiling sound absorbers extend, can be reliably held. Furthermore, the wall sound absorbers placed in the wall lattice section, which are subjected to a vertically downward force along a direction intersecting the direction in which the ceiling sound absorbers extend, can also be reliably held.

[0014] Another embodiment of the present invention, an anechoic chamber ceiling structure, comprises a plurality of ceiling sound absorbers arranged in a two-dimensional manner, and a ceiling lattice member that holds the plurality of ceiling sound absorbers, wherein the ceiling lattice member includes a plurality of ceiling lattice sections into which each of the plurality of ceiling sound absorbers is inserted, and the base end of the sound absorber on the side opposite to the sound absorber tip that is positioned on the room side is smaller than the inner dimensions of the ceiling lattice section. With this configuration, it is possible to hold the ceiling sound absorbers with the ceiling lattice section and to remove the ceiling sound absorbers from the ceiling lattice section.

[0015] An acoustic testing method, which is yet another embodiment of the present invention, comprises the steps of forming a first form in a floor structure including a plurality of floor sound absorbers arranged in two dimensions, a plurality of floor members that can be arranged in two dimensions on the floor sound absorbers, and column members that support the floor members, by arranging a plurality of floor members in two dimensions above the plurality of floor sound absorbers arranged in two dimensions; and placing a test object between the ceiling structure and the floor structure in a ceiling structure including a plurality of ceiling sound absorbers arranged in two dimensions and a ceiling lattice member that holds the plurality of ceiling sound absorbers, by suspending a test object from a suspension part attached to the ceiling lattice member; and forming a second form in which no floor members are placed between the ceiling sound absorbers and the floor sound absorbers by removing the floor members after the step of placing the test object.

[0016] According to this method, a floor can be formed by arranging a plurality of floor members two-dimensionally above a plurality of floor sound absorbers arranged two-dimensionally in an anechoic chamber. As a result, an operator can enter the anechoic chamber, and thus the operation of suspending a test object can be performed. Further, after the operation of suspending the test object, the floor members are removed. As a result, a state in which no floor member is arranged between the ceiling sound absorber and the floor sound absorber can be formed. Therefore, the test can be carried out in a state where factors causing sound reflection are reduced.

Effect of the Invention

[0017] According to the present invention, there are provided an anechoic chamber capable of reducing factors causing sound reflection, a ceiling structure of the anechoic chamber, and an acoustic test method.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a cross-sectional perspective view showing the structure of an anechoic chamber according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing a ceiling structure unit. [Figure 3] FIG. 3 is an exploded perspective view showing a sound absorption wedge insertion frame and a ceiling floor grid constituting the ceiling structure unit. [Figure 4] FIG. 4 is a plan view showing a sound absorption wedge holding frame provided on the sound absorption wedge insertion frame. [Figure 5] FIG. 5(a) is a perspective view showing a state in which a sound absorption wedge is being inserted into the sound absorption wedge holding frame. FIG. 5(b) is an enlarged view showing a main part in the state in which a sound absorption wedge is being inserted into the sound absorption wedge holding frame. [Figure 6] FIG. 6(a) is a perspective view showing a state in which the insertion of the sound absorption wedge into the sound absorption wedge holding frame is completed. FIG. 6(b) is an enlarged view showing a main part in the state in which the insertion of the sound absorption wedge into the sound absorption wedge holding frame is completed. [Figure 7] FIG. 7 is an enlarged perspective view showing a part of a floor structure according to the first embodiment. [Figure 8] FIG. 8 is an enlarged perspective view showing a part of the floor structure. [Figure 9] FIG. 9 is a flowchart showing the main steps of the acoustic test method. [Figure 10] FIG. 10 is a cross-sectional view showing the anechoic chamber just before performing the preparation step. [Figure 11] FIG. 11 is a cross-sectional view schematically showing the step of arranging the acoustic equipment. [Figure 12] FIG. 12 is a cross-sectional view schematically showing the step of adjusting the position and orientation of the acoustic equipment. [Figure 13] FIG. 13 is a cross-sectional view schematically showing the step of carrying out the mesh floor. [Figure 14] FIG. 14 is a cross-sectional view schematically showing the step of carrying out the lighting equipment. [Figure 15] FIG. 15 is a cross-sectional view schematically showing a state where the acoustic test can be started. [Figure 16] FIGS. 16(a) and 16(b) are perspective views showing a floor structure which is a modification.

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0020] <anechoic chamber FIG. 1 is a cross-sectional perspective view showing a part of the anechoic chamber 1 cut away. The anechoic chamber 1 shown in FIG. 1 includes an anechoic region 11 and a ceiling work region 12. The anechoic region 11 is a space for performing various acoustic tests. The ceiling work region 12 is a so-called catwalk. The ceiling work region 12 is a space for an operator to enter and perform various preparation and withdrawal operations for the work associated with the implementation of the acoustic test.

[0021] The anechoic chamber 1 is composed of a ceiling structure 2, a floor structure 3, and a wall structure 4. The space enclosed by the ceiling structure 2, the floor structure 3, and the wall structure 4 is the aforementioned anechoic region 11. The anechoic region 11 is a space enclosed by multiple sound-absorbing wedges arranged without gaps in each of the ceiling structure 2, the floor structure 3, and the wall structure 4. The ceiling structure 2, the floor structure 3, and the wall structure 4 will be described in detail below.

[0022] <Ceiling structure of an anechoic chamber> The ceiling structure 2 (ceiling structure part) is suspended from the ceiling frame 102 by a plurality of suspension members 20 (suspension support parts). In other words, a predetermined space is formed between the ceiling structure 2 and the ceiling frame 102, which is the aforementioned ceiling work area 12. Therefore, the ceiling structure 2 forms the floor of the ceiling work area 12. Furthermore, the ceiling structure 2 forms the ceiling of the anechoic region 11. The ceiling structure 2 can also be said to be the part that separates the anechoic region 11 and the ceiling work area 12. The ceiling structure 2 is formed by a plurality of ceiling structure units 2S arranged in a two-dimensional manner. The plurality of ceiling structure units 2S are connected to each other to form the ceiling of the anechoic region 11 and the floor of the ceiling work area 12.

[0023] Figure 2 is a perspective view showing a disassembled ceiling structure unit 2S. As shown in Figure 2, the ceiling structure unit 2S is mainly made up of three parts. Specifically, the ceiling structure unit 2S has nine ceiling sound-absorbing wedges 21 (ceiling sound absorbers), a sound-absorbing wedge insertion frame 22 (ceiling lattice member), and a ceiling floor lattice 23.

[0024] As shown in Figure 3, the sound-absorbing wedge insertion frame 22 is made up of metal rods with a round or rectangular cross-section. One sound-absorbing wedge insertion frame 22 is connected to an adjacent sound-absorbing wedge insertion frame 22 by a connecting fitting 24. The connecting fitting 24 is positioned on the rod that forms the upper end of the outer periphery of the sound-absorbing wedge insertion frame 22. The floor of the ceiling work area 12 is formed by connecting the sound-absorbing wedge insertion frames 22 using the connecting fitting 24. Furthermore, the lower end of the suspension member 20 is inserted into the gap between adjacent connecting fittings 24 and fixed to the sound-absorbing wedge insertion frame 22 by a bolt that connects the connecting fittings 24.

[0025] The sound-absorbing wedge insertion frame 22 has nine wedge placement sections 220 when viewed from above. Nine ceiling sound-absorbing wedges 21 are inserted into each of the nine wedge placement sections 220. The sound-absorbing wedge insertion frame 22 has the function of holding the inserted ceiling sound-absorbing wedges 21 to prevent them from falling. Furthermore, the sound-absorbing wedge insertion frame 22 also has the function of allowing the inserted ceiling sound-absorbing wedges 21 to be pulled out. This function is achieved by the sound-absorbing wedge holding frame 25 (ceiling lattice section) which is fixed to the lower part of the sound-absorbing wedge insertion frame 22. The sound-absorbing wedge holding frame 25 is fixed to the lower side of the sound-absorbing wedge insertion frame 22.

[0026] Figure 4 is a view from below of the sound-absorbing wedge insertion frame 22 to which the sound-absorbing wedge retaining frame 25 is fixed. In plan view, the sound-absorbing wedge retaining frame 25 is rectangular in shape, with a pair of short sides 251 being shorter than a pair of long sides 252. As shown in Figure 4, in adjacent sound-absorbing wedge retaining frames 25, the long side of one sound-absorbing wedge retaining frame 25 faces the short side of the other sound-absorbing wedge retaining frame 25. In other words, adjacent sound-absorbing wedge retaining frames 25 are oriented 90 degrees apart. This orientation corresponds to the orientation of the ceiling sound-absorbing wedge 21.

[0027] As shown in Figures 5(a) and 5(b), one ceiling sound-absorbing wedge 21 is inserted into one sound-absorbing wedge holding frame 25. The ceiling sound-absorbing wedge 21 will now be briefly explained.

[0028] The ceiling sound-absorbing wedge 21 is made of a relatively soft material that easily absorbs sound. The ceiling sound-absorbing wedge 21 is an integrated component including a wedge portion 211 and a main body portion 212. The wedge portion 211 is composed of a pair of wedge sides 211a that are parallel to each other and a pair of wedge slopes 211b that narrow towards the tip 21e. This wedge portion 211 is exposed to the anechoic region 11 and has the effect of not reflecting sound generated in the anechoic region 11. The main body portion 212 is connected to the base end of the wedge portion 211. The cross-section of the main body portion 212 is approximately square and does not narrow towards the tip 21e like the wedge portion 211.

[0029] Figures 6(a) and 6(b) show the process of inserting the ceiling sound-absorbing wedge 21 into the sound-absorbing wedge retaining frame 25. The ceiling sound-absorbing wedge 21 is inserted so that the wedge slope 211b faces the short side portion 251 of the sound-absorbing wedge retaining frame 25. Figures 6(a) and 6(b) then show the completed insertion of the ceiling sound-absorbing wedge 21 into the sound-absorbing wedge retaining frame 25. As shown in Figure 6(b), the wedge portion 211 is either inside the sound-absorbing wedge retaining frame 25 or passing through the sound-absorbing wedge retaining frame 25. In contrast, the main body portion 212 does not pass through the sound-absorbing wedge retaining frame 25 but is caught on the sound-absorbing wedge retaining frame 25. In the sound-absorbing wedge retaining frame 25, the internal dimension W252 formed by the pair of long sides 252 is approximately the same as the width of the pair of wedge sides 211a and the width of the pair of main body sides 212a. In contrast, the internal dimension W251 formed by the pair of short sides 251 is larger than the width of the pair of wedge bevels 211b, but narrower than the width of the pair of main body sides 212a. Therefore, as shown in Figure 6(b), the pair of main body parts 212 are able to engage with the sound-absorbing wedge retaining frame 25.

[0030] As mentioned above, the sound-absorbing wedge retaining frames 25 attached to the sound-absorbing wedge insertion frame 22 are arranged in a grid pattern, and adjacent sound-absorbing wedge retaining frames 25 are rotated 90 degrees apart. Because adjacent ceiling sound-absorbing wedges 21 are rotated 90 degrees apart, adjacent sound-absorbing wedge retaining frames 25 are also rotated 90 degrees apart.

[0031] The ceiling sound-absorbing wedges 21 that constitute the ceiling structure 2 are subjected to a downward force due to gravity. By having the ceiling sound-absorbing wedges 21 catch on the sound-absorbing wedge holding frame 25, this force prevents the ceiling sound-absorbing wedges 21 from falling from the ceiling work area 12 side to the anechoic area 11 side (downward). Therefore, by arranging multiple ceiling sound-absorbing wedges 21 in a two-dimensional manner, it is possible to form a ceiling area that can exert the function of suppressing sound reflection.

[0032] On the other hand, it is assumed that the ceiling sound-absorbing wedge 21, which is caught in the sound-absorbing wedge holding frame 25, will be lifted upward. In the lifting direction, the sound-absorbing wedge holding frame 25 will not interfere with the ceiling sound-absorbing wedge 21, and no snagging will occur. Therefore, the ceiling sound-absorbing wedge 21 can be pulled out toward the ceiling work area 12 (upward). In other words, the combination of the ceiling sound-absorbing wedge 21 and the sound-absorbing wedge holding frame 25 has two effects: it prevents the ceiling sound-absorbing wedge 21 from falling, and it allows the ceiling sound-absorbing wedge 21 to be easily pulled out. Due to these effects, it is possible to remove the ceiling sound-absorbing wedge 21 as needed to perform work such as installing sound equipment 91, and then put the ceiling sound-absorbing wedge 21 back in place after the work is completed.

[0033] The ceiling and floor grid 23 forms the floor surface of the ceiling work area 12. One ceiling and floor grid 23 is attached to one sound-absorbing wedge insertion frame 22. In other words, workers can walk on the ceiling and floor grid 23. The ceiling and floor grid 23 has a frame portion 231, a grid mesh portion 232, and claw portions 233. The grid mesh portion 232 is exposed at the opening of the frame portion 231, and three claw portions 233 are attached to each side of the upper surface of the frame portion 231. Part of these claw portions 233 protrudes from the side of the frame portion 231. The protruding portion is designed to catch on the upper edge of the connecting fitting 24 mentioned above. With this configuration, the ceiling and floor grid 23 can be removed from the sound-absorbing wedge insertion frame 22 as needed, and the removed ceiling and floor grid 23 can be placed back onto the sound-absorbing wedge insertion frame 22. In other words, the ceiling and floor grid 23 is detachable from the sound-absorbing wedge insertion frame 22.

[0034] <Floor structure of an anechoic chamber> The floor structure 3 (floor structure) is composed of a plurality of floor sound-absorbing wedges 31 (floor sound-absorbing bodies), a sound-absorbing wedge insertion frame 32, a plurality of mesh floors 33 (floor members), and a plurality of support members 34 (column members). The sound-absorbing wedge insertion frame 22 is the same as that of the ceiling structure 2, except that it does not have a sound-absorbing wedge holding frame 25, so its illustration and detailed description are omitted.

[0035] Of the members that make up the floor structure 3, the support members 34 are used only in the floor structure 3. The support members 34 are for laying the mesh floor 33 on top of the sound-absorbing floor wedges 31. The support members 34 are arranged in a grid pattern on top of the floor frame 103. For example, each corner of four mesh floors 33 rests on one support member 34. The support members 34 can be switched between an extended form, which is the longest in length, and a retracted form, which is the shortest in length. When in the extended form, the upper end of the support member 34 is above the tip 31e of the sound-absorbing floor wedges 31. When in the retracted form, the upper end of the support member 34 is below the tip 31e of the sound-absorbing floor wedges 31. For example, when in the retracted form, the upper end of the support member 34 may be below the wedge portion 211 of the sound-absorbing floor wedges 31. In the example shown in Figure 7, the support member 34 includes a base cylindrical portion 340, a first movable cylindrical portion 341, a second movable cylindrical portion 342, and a floor member support portion 343. The base cylindrical portion 340 is fixed to the floor structure 103. The first movable cylindrical portion 341 has an outer diameter smaller than the inner diameter of the base cylindrical portion 340. The first movable cylindrical portion 341 is inserted into the base cylindrical portion 340 and is movable up and down relative to the base cylindrical portion 340. Furthermore, the second movable cylindrical portion 342 has an outer diameter smaller than the inner diameter of the first movable cylindrical portion 341. The second movable cylindrical portion 342 is inserted into the first movable cylindrical portion 341 and is movable up and down relative to the first movable cylindrical portion 341. A disc-shaped floor member support portion 343 is fixed to the upper end of the second movable cylindrical portion 342. The first movable cylindrical part 341 and the second movable cylindrical part 342 are moved by a drive source such as a ball screw mechanism or a hydraulic mechanism.

[0036] In ceiling structure 2 and wall structure 4, ceiling sound-absorbing wedges 21 and wall sound-absorbing wedges 41 are exposed in all areas facing the room, both during testing and during preparation / dismantling. In contrast, floor structure 3 can have two configurations: a first configuration in which areas facing the room include both exposed floor sound-absorbing wedges 31 and exposed support members 34, and a second configuration in which floor sound-absorbing wedges 31 are exposed in all areas facing the room. The first configuration can be adopted during preparation / dismantling. In the first configuration (see Figure 10), the mesh floor 33 is laid out, and workers 70 can enter the room. The second configuration can be adopted during acoustic testing. In the second configuration (see Figure 15), the mesh floor 33 is not present on top of the floor sound-absorbing wedges 31 that constitute floor structure 3. Furthermore, in the second form, the support material 34 is in a contracted state, and the floor sound-absorbing wedge 31 is also placed over it.

[0037] <Wall structure of an anechoic chamber> Like the ceiling structure 2 and floor structure 3, the wall structure 4 is formed by arranging multiple floor sound-absorbing wedges 31 (wall sound absorbers) in a two-dimensional manner. Part of the wall structure 4 serves as an entrance / exit for entering the anechoic region 11. The wall structure 4 is composed of a sound-absorbing wedge insertion frame (wall lattice member, not shown) and multiple floor sound-absorbing wedges 31. The floor sound-absorbing wedges 31 that make up the wall structure 4 are arranged perpendicular to the direction of gravity. Therefore, unlike the ceiling sound-absorbing wedges 21 that make up the ceiling structure 2, they are not pulled downward by the total weight of the ceiling sound-absorbing wedges 21. For this reason, there is no need to provide a sound-absorbing wedge holding frame 25 on the sound-absorbing wedge insertion frame 22 as in the ceiling structure 2, and the position of the floor sound-absorbing wedge 31 can be maintained simply by inserting the main body 212 of the floor sound-absorbing wedge 31 into the sound-absorbing wedge insertion frame 22.

[0038] Furthermore, the wall structure 4 may be provided with a portion for connecting the end of a position adjustment wire 85 for adjusting the position and orientation of components such as acoustic equipment 91 placed in the anechoic region 11. In addition, a winch (not shown) for adjusting the length of the position adjustment wire 85 may be provided as needed.

[0039] <Acoustic Testing Methods> Next, an acoustic test method using anechoic chamber 1 will be described with reference to Figures 9 to 15. The acoustic test method includes at least a preparation step S1 and a test step S2. The acoustic test method may include, but may not include, a dismantling step S3 performed after the test step S2.

[0040] Figure 10 shows the initial state T1 (first form, see Figure 7) of the anechoic chamber 1 immediately before the start of preparation step S1. The process of forming the initial state T1 is step S0, as shown in the flowchart of Figure 9. Two lighting fixtures 92 are placed in the anechoic area 11 of the anechoic chamber 1. Furthermore, the floor structure 3 includes a two-dimensionally laid mesh floor 33. In this state of the anechoic chamber 1, workers can enter the anechoic area 11 and perform various preparatory tasks.

[0041] Next, the sound equipment 91 is placed in the anechoic region 11 (S11). First, the worker 70 brings the sound equipment 91 into the anechoic region 11. The worker 70 places the sound equipment 91 in the designated position on the mesh floor 33. Next, as shown in Figure 11, the worker 70 enters the ceiling work area 12. The worker 70 removes the ceiling floor grid 23 that is located directly above the area where the sound equipment 91 is placed. Once the ceiling floor grid 23 is removed, the wedge base end face 21t of the ceiling sound-absorbing wedge 21 (see Figure 5(a)) is exposed, making it possible to pull out the ceiling sound-absorbing wedge 21. The worker 70 then pulls out several of the ceiling sound-absorbing wedges 21. This temporarily forms a through hole from the ceiling work area 12 to the anechoic region 11. Through this hole, a suspension wire 81 (suspension part) for suspending the sound equipment 91 is lowered from the ceiling work area 12 to the anechoic area 11. After that, the worker 70 puts the removed ceiling sound-absorbing wedge 21 back into the original through-hole.

[0042] Next, as shown in Figure 12, the worker 70 entering the anechoic zone connects the sound equipment 91 to the end of the suspension wire 81. Furthermore, the worker 70 connects the end of the position adjustment wire 85 to the sound equipment 91. Then, the worker 70 operates the suspension winch 811 to position the sound equipment 91 at a predetermined height. For example, the height at which the sound equipment 91 is positioned can be defined by the height relative to the tip of the floor sound-absorbing wedge 31 constituting the floor structure 3, and the distance relative to the tip of the wall sound-absorbing wedge 41 constituting the wall structure 4. Next, the worker 70 operates the position adjustment winch 821, etc., to position the sound equipment 91 at a predetermined position when the anechoic zone 11 is viewed from above. At this time, in addition to adjusting the position relative to the XY axes on the floor plane, the orientation of the sound equipment 91 may also be adjusted. The orientation of the sound equipment 91 can be defined by the inclination angle around the X axis, the inclination angle around the Y axis, and the inclination angle around the Z axis.

[0043] Furthermore, the worker 70, after performing a series of operations similar to those for positioning the acoustic equipment 91 in a predetermined position and orientation, positions the measuring instrument 93 in a predetermined position and orientation within the anechoic zone 11 (S12). In this example, the acoustic equipment 91 is positioned first, followed by the measuring instrument 93, but this order may be reversed. There are no particular restrictions on the order in which the multiple pieces of equipment required for acoustic testing are positioned in the anechoic zone 11.

[0044] Furthermore, in this example, the mesh floor 33 is completely removed from the anechoic chamber 11 in a later step. Therefore, the equipment required for acoustic testing cannot be placed on the mesh floor 33. Thus, in this example, all the equipment required for acoustic testing is suspended from the ceiling structure 2 and placed in the anechoic chamber 11. As mentioned above, the ceiling sound-absorbing wedges 21 that constitute the ceiling structure 2 can be removed from the sound-absorbing wedge insertion frame 22 at any position and then inserted back into the sound-absorbing wedge insertion frame 22. Because such operations are possible, the anechoic chamber 1 in this example can be configured to accommodate the equipment required for acoustic testing at any position when viewed from above.

[0045] Next, worker 70 removes from the anechoic zone 11 any components that were brought into the anechoic zone 11 before the acoustic test but are not needed during the acoustic test (S13).

[0046] First, as shown in Figure 13, the mesh floor 33 is removed from the anechoic region 11 (S13a). Even after the mesh floor 33 is removed from the support beam 34, the support beam 34 remains in place. Since this support beam 34 is made of a metal material with sufficient strength, it can be a factor in reflecting sound. Therefore, work is performed to suppress sound reflection by this support beam 34 as well. Specifically, the support beam 34 from which the mesh floor 33 has been removed is compressed. As mentioned above, the support beam 34 consists of three cylindrical members, and the two upper cylindrical members can move toward the structure relative to the cylindrical member fixed to the floor structure 103. When this is done, the floor member support portion 343 of the support beam 34 was located above the tip 31e of the floor sound-absorbing wedge 31, but by compressing it, the floor member support portion 343 of the support beam 34 is located below the tip 31e of the floor sound-absorbing wedge 31. In this configuration, sound reflection can be suppressed more effectively than when the floor member support portion 343 is positioned above the tip 31e of the floor sound-absorbing wedge 31. To further suppress sound reflection, the floor sound-absorbing wedge 31 may be placed over the retracted support member 34. This floor sound-absorbing wedge 31 has a hollowed-out interior that can accommodate the retracted support member 34.

[0047] In short, the process of removing the mesh floor 33 from the anechoic chamber 1 (S13a) includes removing the mesh floor 33, compressing the support members 34, and covering the compressed support members 34 with the floor sound-absorbing wedges 31. By repeating these operations from the side furthest from the entrance of the anechoic region 11 toward the entrance, the entire floor of the anechoic region 11 can be made to be formed by the floor sound-absorbing wedges 31.

[0048] Next, as shown in Figure 14, the lighting equipment 92 is carried out of the anechoic zone 11 (S13b). The worker 70, who has entered the ceiling work area 12, removes the ceiling and floor grid 23 and floor sound-absorbing wedges 31 at the location where the lighting suspension wire 81 extends. Next, the worker 70 pulls the lighting suspension wire 81 closer, carrying the lighting equipment 92, which is connected to the end of the lighting suspension wire 81, from the anechoic zone 11 to the ceiling work area 12. Then, the worker 70 reinserts the floor sound-absorbing wedges 31, which had been temporarily removed, into the sound-absorbing wedge insertion frame 22, and then reattaches the ceiling and floor grid 23.

[0049] Other equipment suspended from the ceiling structure 2 can also be removed from the anechoic zone 11 using the same procedure.

[0050] Through the above steps, the test start-up state T2 (second form, see Figure 8) shown in Figure 15 is formed. Then, the acoustic test is performed by operating the acoustic equipment 91 and measuring equipment 93 from outside the anechoic region 11 (S2).

[0051] Furthermore, after the acoustic test (test step S2) is completed, the acoustic equipment 91 and measuring equipment 93 are removed.

[0052] First, the lighting equipment 92 is installed in the anechoic zone 11 (S31). The process of installing the lighting equipment 92 in the anechoic zone 11 can be carried out in the reverse order of the process of removing the lighting equipment 92 from the anechoic zone 11 (S13b). The worker 70, having entered the ceiling work area 12, removes the ceiling sound-absorbing wedge 21 at the position where the lighting equipment 92 will be suspended. Next, the worker 70 connects the lighting equipment 92, which was removed from the anechoic zone 11 in the process (S13b), to the lighting support mechanism 83, and lowers the lighting equipment 92 to the anechoic zone 11 to a predetermined height through the hole created by removing the ceiling sound-absorbing wedge 21. Then, the worker 70 reinserts the removed ceiling sound-absorbing wedge 21 into the sound-absorbing wedge insertion frame 22.

[0053] Next, the mesh floor 33 is brought into the anechoic zone 11 to create a state where the worker 70 can enter the anechoic zone 11 (S32). This process of forming the mesh floor can be carried out by the reverse procedure of the process of removing the mesh floor 33 from the anechoic zone 11 (S13a). First, the floor sound-absorbing wedges 31 that were covering some of the bundle members 34 closest to the entrance are removed. Next, the contracted bundle members 34 are extended. Then, the mesh floor 33 is placed on the floor member support parts 343 that are located above the tips 21e of the floor sound-absorbing wedges 31. In other words, by repeatedly removing the floor sound-absorbing wedges 31, extending the bundle members 34, and placing the mesh floor 33 from the entrance towards the back, a floor is formed in the anechoic zone 11.

[0054] Next, the sound equipment 91 and measuring equipment 93 are removed (S33). First, worker 70, who has entered the anechoic zone 11 that forms the floor, loosens the position adjustment wire 85. Next, worker 70, who has entered the ceiling work area 12, removes the ceiling sound-absorbing wedge 21 near the suspension wire 81 that is suspending the sound equipment 91. Next, he operates the suspension winch 811 to lower the sound equipment 91 onto the mesh floor 33. Next, he removes the suspension wire 81 and the position adjustment wire 85 from the sound equipment 91. Then, worker 70 takes the sound equipment 91 out of the anechoic zone 11. Also, worker 70, who has entered the ceiling work area 12, operates the suspension winch 811 to wind up the suspension wire 81 to its initial position. Then, he inserts the removed ceiling sound-absorbing wedge 21 back into the sound-absorbing wedge insertion frame 22.

[0055] After completing the above steps (S1, S2, S3), the removal of the acoustic equipment 91 and measuring equipment 93 is finished, and the anechoic chamber 1 returns to its original initial state.

[0056] <Effects and Effects> The anechoic chamber 1 comprises a ceiling structure 2 including a plurality of ceiling sound-absorbing wedges 21 arranged in a two-dimensional manner and a sound-absorbing wedge insertion frame 22 that holds the plurality of ceiling sound-absorbing wedges 21; and a floor structure 3 including a plurality of floor sound-absorbing wedges 31 arranged in a two-dimensional manner, a plurality of mesh floors 33 that can be arranged in a two-dimensional manner between the ends of the floor sound-absorbing wedges 31 and the ends of the ceiling sound-absorbing wedges 21, and a support member 34 that supports the mesh floors 33. The ceiling structure 2 includes suspension wires 81 attached to the sound-absorbing wedge insertion frame 22 for positioning acoustic equipment 91 between the ceiling structure 2 and the floor structure 3. The floor structure 3 is switchable between an initial state T1 in which the plurality of mesh floors 33 are positioned between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21, and a test-start ready state T2 in which the plurality of mesh floors 33 are not positioned between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21.

[0057] This anechoic chamber 1 allows for the placement of acoustic equipment 91 between the ceiling sound-absorbing wedges 21 and the floor sound-absorbing wedges 31. This placement work involves a worker 70 entering the anechoic chamber 1, which is the anechoic area 10, and placing the acoustic equipment 91 in the designated position. However, by using the initial state T1 in which multiple mesh floors 33 are placed between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21, it is possible to perform the work inside the anechoic chamber 1. Furthermore, during the acoustic test S2, since the acoustic equipment 91 is suspended from the sound-absorbing wedge insertion frame 22 of the ceiling structure 2, there is no need to support it from the floor. As a result, during the acoustic test S2, the test start-up state T2 can be used in which multiple mesh floors 33 are not placed between the floor sound-absorbing wedges 31 and the ceiling sound-absorbing wedges 21. Therefore, the acoustic test S2 can be performed without the mesh floors 33, which can be a factor in generating sound reflection, in place.

[0058] The support member 34 includes a floor member support portion 343 on which the mesh floor 33 is placed. When the floor structure 3 is in its initial state T1, the floor member support portion 343 is located between the floor sound-absorbing wedge 31 and the ceiling sound-absorbing wedge 21. When the floor structure 3 is in a test-ready state T2, the floor member support portion 343 is located between the tip and base of the floor sound-absorbing wedge 31. This configuration makes it possible to suppress sound reflection caused by the floor member support portion 343.

[0059] The suspension wire 81 includes a position adjustment wire 82 for adjusting the distance from the tip 21e of the ceiling sound-absorbing wedge 21 to the sound equipment 91, or from the tip 21e of the floor sound-absorbing wedge 31 to the sound equipment 91. With this configuration, the sound equipment 91 can be positioned at a desired location within the anechoic chamber 1.

[0060] When the floor structure 3 is in its initial state T1, the lighting equipment 92 is placed between the floor sound-absorbing wedge 31 and the ceiling sound-absorbing wedge 21. When the floor structure 3 is in a test-ready state T2, the lighting equipment 92 does not need to be placed between the floor sound-absorbing wedge 31 and the ceiling sound-absorbing wedge 21. With this configuration, when the acoustic equipment 91 is placed inside the anechoic chamber 1, the lighting equipment 92 can brighten the interior of the anechoic chamber 1, making the interior of the anechoic chamber 1 more suitable for work. Furthermore, when conducting the acoustic test S2, the lighting equipment 92, which could cause sound reflection, is not present inside the anechoic chamber 1. Therefore, factors that cause sound reflection can be reduced.

[0061] The sound-absorbing wedge insertion frame 22 is connected to the ceiling structure 102 by the suspension member 20. With this configuration, a ceiling work area 12 can be provided between the ceiling structure 102 and the ceiling structure 2.

[0062] The anechoic chamber 1 comprises a wall structure 4 including a plurality of wall sound-absorbing wedges 41 arranged in a two-dimensional manner, and a wall grid member 42 that holds the plurality of wall sound-absorbing wedges 41. This configuration makes it possible to suppress the occurrence of sound reflections on the wall side of the anechoic chamber 1.

[0063] The sound-absorbing wedge insertion frame 22 includes a plurality of sound-absorbing wedge holding frames 25 into which each of the plurality of ceiling sound-absorbing wedges 21 is inserted. The wall lattice member includes a plurality of wall lattice sections into which each of the plurality of wall sound-absorbing bodies is inserted. The size of the sound-absorbing wedge holding frame 25 is smaller than the size of the wall lattice section. With this configuration, the ceiling sound-absorbing wedges 21 can be reliably held in the sound-absorbing wedge holding frame 25, which is subjected to a vertically downward force along the direction in which the ceiling sound-absorbing wedges 21 extend. It can also reliably hold the wall sound-absorbing bodies placed in the wall lattice sections, which are subjected to a vertically downward force along a direction intersecting the direction in which the ceiling sound-absorbing wedges 21 extend.

[0064] The ceiling structure of the anechoic chamber 1 comprises a plurality of ceiling sound-absorbing wedges 21 arranged in a two-dimensional manner, and a sound-absorbing wedge insertion frame 22 that holds the plurality of ceiling sound-absorbing wedges 21. The sound-absorbing wedge insertion frame 22 includes a plurality of sound-absorbing wedge holding frames 25 into which each of the plurality of ceiling sound-absorbing wedges 21 is inserted. The main body portion 212 of the ceiling sound-absorbing wedge 21 on the side opposite to the tip 21e of the ceiling sound-absorbing wedge 21 that is positioned on the room side is smaller than the inner dimensions W251 of the short side portion 251 of the sound-absorbing wedge holding frame 25. With this configuration, it is possible to hold the ceiling sound-absorbing wedges 21 with the sound-absorbing wedge holding frame 25 and to remove the ceiling sound-absorbing wedges 21 from the sound-absorbing wedge holding frame 25.

[0065] The acoustic testing method involves a floor structure 3 comprising a plurality of floor sound-absorbing wedges 31 arranged in a two-dimensional manner, a plurality of mesh floors 33 that can be arranged in a two-dimensional manner on the floor sound-absorbing wedges 31, and support members 34 that support the mesh floors 33, wherein the method includes a step S0 in which an initial state T1 is formed by arranging the plurality of mesh floors 33 in a two-dimensional manner above the plurality of floor sound-absorbing wedges 31, a plurality of ceiling sound-absorbing wedges 21 arranged in a two-dimensional manner, and a sound-absorbing wedge insertion frame 2 that holds the plurality of ceiling sound-absorbing wedges 21. In a ceiling structure 2 including 2, the procedure includes steps S11 and S12 of suspending the sound equipment 91 from suspension wires 81 attached to sound-absorbing wedge insertion frames 22, thereby arranging the sound equipment 91 between the ceiling structure 2 and the floor structure 3, and step S13 of removing the mesh floor 33 after steps S11 and S12 of arranging the sound equipment 91, thereby creating a test start-ready state T2 in which the mesh floor 33 is not positioned between the ceiling sound-absorbing wedges 21 and the floor sound-absorbing wedges 31.

[0066] According to this method, a floor can be formed in the anechoic chamber 1 by arranging multiple mesh floors 33 in a two-dimensional manner above multiple floor sound-absorbing wedges 31 arranged in a two-dimensional manner. As a result, the worker 70 can enter the anechoic chamber 1 and perform the work of suspending the sound equipment 91. Furthermore, the mesh floors 33 are removed after the work of suspending the sound equipment 91. As a result, a state can be created in which the mesh floors 33 are not placed between the ceiling sound-absorbing wedges 21 and the floor sound-absorbing wedges 31. Therefore, the acoustic test S2 can be performed in a state in which factors that reflect sound are reduced.

[0067] <Variation> The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0068] For example, the anechoic chamber may have a floor structure 2A as shown in Figure 16(a). The top mesh portion 331 of the mesh floor 33A is connected to the floor frame 333 via a hinge portion 332. In this configuration, when the entire mesh floor 33A, including the hinge portion 332 and the top mesh portion 331, is moved downward, the top mesh portion 331 comes into contact with the floor sound-absorbing wedge 31, and its orientation becomes approximately vertical (see Figure 16(b)). In other words, it can be made to look like double doors. As a result, the floor sound-absorbing wedge 31, which was covered by the top mesh portion 331, is exposed. Although the top mesh portion 331 is located in the anechoic region 11, the portion facing the anechoic region 11 and contributing to sound reflection is the end face of the top mesh portion 331. As a result, the occurrence of sound reflection can be sufficiently suppressed.

[0069] <Note> This disclosure also includes the following components:

[0070] This disclosure includes [1] a ceiling structure comprising a plurality of ceiling sound absorbers arranged in a two-dimensional manner, and a ceiling grid member that holds the plurality of ceiling sound absorbers, The floor structure comprises a plurality of floor sound-absorbing elements arranged in a two-dimensional manner, a plurality of floor members that can be arranged in a two-dimensional manner between the front ends of the floor sound-absorbing elements and the front ends of the ceiling sound-absorbing elements, and column members that support the floor members. The ceiling structure includes a suspension section attached to the ceiling grid member for positioning an object to be suspended between the ceiling structure and the floor structure. The aforementioned floor structure is A first embodiment in which a plurality of the floor members are arranged between the floor sound absorber and the ceiling sound absorber, An anechoic chamber that can be switched between a second form in which no multiple floor members are placed between the floor sound absorber and the ceiling sound absorber.

[0071] This disclosure includes [2] "the column member includes a floor member support portion on which the floor member is placed, When the floor structure is in the first embodiment, the floor member support is located between the floor sound absorber and the ceiling sound absorber. When the floor structure is the second embodiment, the floor member support is located between the front and base ends of the floor sound absorber, in the anechoic chamber described in [1] above.

[0072] This disclosure is [3] "an anechoic chamber according to [1] or [2] above, wherein the suspension portion includes a position adjustment portion for adjusting the distance from the tip of the ceiling sound absorber to the object to be suspended, or the distance from the tip of the floor sound absorber to the object to be suspended."

[0073] This disclosure includes [4] "The object to be suspended is a lighting fixture placed between the ceiling structure and the floor structure, When the floor structure is in the first embodiment, the lighting fixture is placed between the floor sound absorber and the ceiling sound absorber. The anechoic chamber described in any one of the above [1] to [3], wherein the floor structure is the second embodiment, and the lighting fixture is not positioned between the front and base ends of the floor sound absorber.

[0074] This disclosure further includes [5] "a ceiling-side structural section, The ceiling lattice member is connected to the ceiling-side structural member by a suspension support, in the anechoic chamber described in any one of the above items [1] to [4].

[0075] The present disclosure is [6] "an anechoic chamber according to any one of the above [1] to [5], further comprising a wall structure including a plurality of wall sound absorbers arranged in a two-dimensional manner and a wall grid member that holds the plurality of wall sound absorbers."

[0076] This disclosure includes [7] "the ceiling lattice member includes a plurality of ceiling lattice sections into which each of the plurality of ceiling sound absorbers is inserted, The wall lattice member includes a plurality of wall lattice sections into which each of the plurality of wall sound absorbers is inserted, The anechoic chamber described in [6] above, wherein the size of the ceiling lattice is smaller than the size of the wall lattice.

[0077] This disclosure includes [8] "a plurality of ceiling sound absorbers arranged in a two-dimensional manner, A ceiling lattice member that holds a plurality of the aforementioned ceiling sound absorbers, The ceiling lattice member includes a plurality of ceiling lattice sections into which each of the plurality of ceiling sound absorbers is inserted. In the aforementioned ceiling sound absorber, the base end of the sound absorber opposite to the tip of the sound absorber positioned on the room side is smaller than the inner dimensions of the ceiling grid, thus forming an anechoic chamber ceiling structure.

[0078] This disclosure includes [9] "a floor structure comprising a plurality of floor sound-absorbing bodies arranged in a two-dimensional manner, a plurality of floor members that can be arranged in a two-dimensional manner on the floor sound-absorbing bodies, and column members that support the floor members, wherein a first embodiment is formed by arranging the plurality of floor members in a two-dimensional manner above the plurality of floor sound-absorbing bodies arranged in a two-dimensional manner," In a ceiling structure comprising a plurality of ceiling sound-absorbing elements arranged in a two-dimensional manner and a ceiling lattice member that holds the plurality of ceiling sound-absorbing elements, the process of suspending the object to be tested from a suspension part attached to the ceiling lattice member, thereby positioning the object to be tested between the ceiling structure and the floor structure, The acoustic testing method comprises the step of removing the floor member after the step of placing the object to be tested, thereby forming a second configuration in which the floor member is not placed between the ceiling sound absorber and the floor sound absorber. [Explanation of symbols]

[0079] 1...Anechoic chamber, 2...Ceiling structure (ceiling structural part), 3...Floor structure (floor structural part), 20...Suspension material (suspending support part), 21...Ceiling sound-absorbing wedge (ceiling sound-absorbing body), 22...Sound-absorbing wedge insertion frame (ceiling lattice member), 25...Sound-absorbing wedge holding frame (ceiling lattice part), 31...Floor sound-absorbing wedge (floor sound-absorbing body), 31...Floor sound-absorbing wedge (wall sound-absorbing body), 33...Mesh floor (floor member), 34...Bracket material (column member), 42...Wall lattice member, 81...Suspension wire (suspending part), 343...Floor member support part, T1...Initial state (first form), T2...Test start ready state (second form), W251...Internal dimensions.

Claims

1. A ceiling structure comprising a plurality of ceiling sound-absorbing elements arranged in a two-dimensional manner, and a ceiling grid member that holds the plurality of ceiling sound-absorbing elements, The floor structure comprises a plurality of floor sound-absorbing elements arranged in a two-dimensional manner, a plurality of floor members that can be arranged in a two-dimensional manner between the front ends of the floor sound-absorbing elements and the front ends of the ceiling sound-absorbing elements, and column members that support the floor members. The ceiling structure includes a suspension section attached to the ceiling grid member for positioning an object to be suspended between the ceiling structure and the floor structure. The aforementioned floor structure is A first embodiment in which a plurality of the floor members are arranged between the floor sound absorber and the ceiling sound absorber, An anechoic chamber that can be switched between a second form in which no multiple floor members are arranged between the floor sound absorber and the ceiling sound absorber.

2. The column member includes a floor member support portion on which the floor member is placed, When the floor structure is in the first embodiment, the floor member support is located between the floor sound absorber and the ceiling sound absorber. The anechoic chamber according to claim 1, wherein when the floor structure is the second embodiment, the floor member support is located between the front and base ends of the floor sound absorber.

3. The anechoic chamber according to claim 1, wherein the suspension section includes a position adjustment section for adjusting the distance from the tip of the ceiling sound absorber to the object to be suspended, or the distance from the tip of the floor sound absorber to the object to be suspended.

4. The object to be suspended is a lighting fixture placed between the ceiling structure and the floor structure. When the floor structure is in the first form, the lighting fixture is placed between the floor sound absorber and the ceiling sound absorber. The anechoic chamber according to claim 1, wherein when the floor structure is the second embodiment, the lighting fixture is not positioned between the front and base ends of the floor sound absorber.

5. The ceiling side structural section is further equipped, The anechoic chamber according to claim 1, wherein the ceiling lattice member is connected to the ceiling side structure by a suspension support.

6. The anechoic chamber according to claim 1, further comprising a wall structure including a plurality of wall sound-absorbing elements arranged in a two-dimensional manner, and a wall grid member that holds the plurality of wall sound-absorbing elements.

7. The ceiling lattice member includes a plurality of ceiling lattice sections into which each of the plurality of ceiling sound absorbers is inserted. The wall lattice member includes a plurality of wall lattice sections into which each of the plurality of wall sound absorbers is inserted, The anechoic chamber according to claim 6, wherein the size of the ceiling lattice is smaller than the size of the wall lattice.

8. Multiple ceiling sound absorbers arranged in a two-dimensional pattern, A ceiling lattice member that holds a plurality of the aforementioned ceiling sound absorbers, The ceiling lattice member includes a plurality of ceiling lattice sections into which each of the plurality of ceiling sound absorbers is inserted. The ceiling structure of an anechoic chamber, wherein the base end of the sound-absorbing element on the opposite side from the tip of the sound-absorbing element, which is positioned on the room side, is smaller than the inner dimensions of the ceiling grid.

9. A floor structure comprising a plurality of sound-absorbing floor elements arranged in a two-dimensional manner, a plurality of floor members that can be arranged in a two-dimensional manner on the sound-absorbing floor elements, and column members that support the floor members, wherein a first form is formed by arranging the plurality of floor members in a two-dimensional manner above the plurality of sound-absorbing floor elements arranged in a two-dimensional manner, In a ceiling structure comprising a plurality of ceiling sound-absorbing elements arranged in a two-dimensional manner and a ceiling lattice member that holds the plurality of ceiling sound-absorbing elements, the process of suspending the object to be tested from a suspension part attached to the ceiling lattice member, thereby positioning the object to be tested between the ceiling structure and the floor structure, An acoustic testing method comprising the step of removing the floor member after the step of arranging the object to be tested, thereby forming a second configuration in which the floor member is not placed between the ceiling sound absorber and the floor sound absorber.

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