WO2015072780A1

WO2015072780A1 - Variable reverberation device having frequency selection and spread function

Info

Publication number: WO2015072780A1
Application number: PCT/KR2014/010959
Authority: WO
Inventors: 김재평; 배성근; 현진오; 김지경; 이에스더
Original assignee: 김재평; 주식회사 케빅; 대림대학교 산학협력단
Priority date: 2013-11-15
Filing date: 2014-11-14
Publication date: 2015-05-21
Also published as: KR101765993B1; KR101498389B1; KR20160058661A

Abstract

The present invention relates to a variable reverberation device. A variable reverberation device (47) according to the present invention further comprises: a plurality of planar panels (41) that perform functions of reflection surfaces; a rotating rod (42) that acts as a rotation axis so that one end of the panel (41) is fixed to be able to rotate; a plurality of grooves (43) formed in the longitudinal direction by the width and the length of the panel (41) so that one end of the panel (41) is fixed to the rotating rod (42); a structure (46) which has a height, a width and a length to allow the plurality of panels (41) to rotate in one direction of the rotating rod (42) in a state of attachment to the rotating rod (42), the structure consisting of floor and ceiling surfaces so that the rotating rod (42) is fixed, comprising a front side having a hexahedron shape in an open form, and housing the panels (41) and the rotating rod (42) and sending out a sound spread from the front side thereof; and a plurality of sound absorbing surfaces (44) attached to the opposite sides of the reflection surfaces to be integral with the reflection surfaces.

Description

Variable Reverberation with Frequency Selection and Diffusion

The present invention relates to the reverberation control of a theater, and more particularly to a variable reverberation device having a frequency selection and spreading function. It should be understood that the variable reverberation device of the present invention includes a technique for a frequency response controller and a variable diffusion device using a Helmholtz resonator, which can adjust the sound absorption frequency band.

Conventionally, a technique of attaching a flaw material made of a porous material to a wall of a building has been used to adjust reverberation of a concert hall inside a building. The advantage of this method is that the soundproofing can be easily performed, and the sound absorbing material structure is relatively simple. The disadvantage of this method, however, is that sound absorption at certain frequencies is not possible. In addition, in order to absorb reverberation of a specific frequency, there is a problem in that a new sound absorbing material for a specific frequency needs to be reattached and constructed.

Therefore, in order to solve these problems, a semi-active sound absorbing device capable of changing the sound absorbing frequency has been used. Korean Patent No. 10-0936786 (registered on Jan. 6, 2010, "Semi Active Sound Absorption System and Sound Absorption Method Using the Same") corresponds to this. This patent installs a porous sound absorbing plate so that an air layer is located between a wall, and adjusts the distance between a porous sound absorbing plate and a wall, and changes a sound absorption frequency by adjusting the thickness of an air layer. However, the problem of this patent cannot be applied when the amount of change in sound absorption frequency is large, and when the amount of change in sound absorption frequency is large, it is solved by further increasing the thickness displacement of the air layer between the wall and the sound absorbing plate by making the moving distance of the wall longer. However, in this case there is a problem that the indoor space is reduced by that much.

On the other hand, hall-specific reflection sounds occur in the interior space of a building (for example, a hall). Among those who listen to the sound source in the sound source, there is a direct sound that is directly transmitted to the listener in the sound source, and there is an initial reflection sound that is reflected by the ceiling or the floor and is transmitted to the listener. And there is reverberation after the initial reflection. This reverberation is determined by the sound absorption characteristics of the hall, and the appropriate reverberation of the hall depends on the sound source (voice, music, etc.). In general, the speech is dry and the voice intelligibility is centered, and the music is appropriately sounded and the music intelligibility is centered.

The reverberation is the time when the sound energy is one millionth of its normal state after the sound source is stopped, and the time that the sound pressure level is 60 dB away. This reverberation time depends on the purpose of the various spaces. For example, concert halls, catholic churches, opera houses, conference halls, and television studios have different reverberations, and even concert halls have different reverberations.

Direct sound expresses sound quality and affects hearing by volume. The reflected sound is a signal delayed by about 20 ~ 50ms, and the direction of incidence and the level are in a functional relationship, reinforcing the direct sound, emphasizing intelligibility, and affecting the hearing. The reverberation sound is omnidirectional, so it arrives in all directions and has a reflection sound after about 50 ms. The reverberation sound deteriorates clarity but has an auditory effect.

The general sound absorbing materials include porous sound absorbing materials, resonance sound absorbing materials, and plate vibration absorbing materials. Porous sound absorbing material is excellent in mid and high sound absorption ability, resonance type sound absorbing material is excellent in narrow band sound absorption ability, and plate vibration type sound absorbing material is excellent in sound absorption ability in low frequency band. However, each of them has advantages and disadvantages, so one of them is not the best.

Therefore, there has been a need for a variable reverberation device having a function of selecting and spreading frequencies, which can solve the problems of these prior arts. Under this background, the invention was devised.

The technical problem to be solved by the present invention is to provide a variable reverberation device having a frequency selection and spreading function. In particular, it is an object of the present invention to provide an active sound absorbing device, a variable reverberation device and a variable diffusion device that can widen the range of change of sound absorption frequency without increasing the displacement of the thickness of the air layer behind the sound absorbing plate. These techniques are a group of inventions that are closely related to each other around a variable reverberation apparatus.

Other objects and advantages of the present invention will become more apparent upon reading the detailed description of the invention described below and referring to the accompanying drawings.

One preferred embodiment of the active sound absorbing device according to the present invention,

By varying the volume of the device interior space and the resonator inlet area, the band of sound absorption frequency is widened.

In this embodiment, the active sound absorbing device,

A hollow housing having one side surface open; And

A variable sound absorbing part inserted into the upper housing part to move inside the housing part to adjust an internal volume of the housing part and to adjust an opening ratio of a perforating part communicating the inside and the outside of the housing part;

It is preferable to comprise a.

In this embodiment, the variable sound absorption unit,

A volume and resonator inlet area adjusting plate inserted into the housing and variably adjusting the internal volume and the resonator inlet area of the housing according to a position adjustment;

It is preferable to comprise.

In this embodiment, an exposed portion consisting of a plurality of perforations is provided at a position facing the perforated portion of the volumetric and resonator inlet area adjusting plate, the position is adjusted in close contact with the front surface of the volume adjusting plate, and the exposed portion is provided. Opening ratio adjusting plate for adjusting the opening ratio of the above-mentioned perforations;

It is preferred to further comprise.

In this embodiment, the above perforations are a plurality of circular or slit through holes, the diameter is optionally variable, the pitch between the holes is preferably an example that varies depending on the overall size of the enclosure.

In this embodiment, the aperture control plate is provided in plurality, it is preferable to form the thickness of each aperture control plate and the depth of the exposed portion different.

In this embodiment, the opening ratio adjusting plate is provided with a plurality of upper exposed portions, it is preferable that the depth of each exposed portion is formed differently.

In this embodiment, it is preferable that the inside of the gastric enclosure further includes a guide for allowing the variable sound absorbing portion to be moved.

In this embodiment, the upper guide portion is preferably one of the one formed by attaching a groove, a projection or a separate member provided inside the upper housing portion.

In this embodiment, it is preferable that the front edge of the volumetric and resonator inlet area adjusting plate further includes a slide guide capable of moving the aperture control plate in close contact with the volume and resonator inlet area adjusting plate.

In this embodiment, the volumetric and resonator inlet area adjusting plates are provided with protrusions engaging with the upper guide portion when the upper guide portion is in the shape of a groove, and the volume adjusting plate when the guide portion has a structure protruding by the protrusion or attaching a separate member. It is preferable that there is a groove provided in the upper guide part.

One preferred embodiment of the variable diffusion device according to the present invention,

This results in the attenuation pattern of the reflected sound for the direct sound in a given spread space being exponentially attenuated.

Over time, the surface of the diffuser is formed into a polygon to prevent flutter echoes and maintain IACC values of 0.5 or less without sacrificing sound intelligibility.

The polygonal diffuser has a triangular or oval structure and the relationship between the width (a) and height (b) of the diffuser

While maintaining

At this time

Is a wavelength of sound to be absorbed.

In this embodiment,

A plurality of flat panels;

One end of the upper panel is fixed to the rotating rod to serve as a rotating shaft to rotate;

A plurality of grooves formed longitudinally by the width and length of the panel so that one end of the panel is fixed to the rotary rod;

The plurality of panels are attached to the rotating rod with a height, horizontal and vertical size that can rotate in one direction of the rotating rod, and consists of a bottom and a ceiling surface to fix the rotating rod, and the front part has an open hexahedral shape. A structure accommodating the panel and the rotating rod and emitting a diffused sound to the front portion;

It is preferable to comprise.

In this embodiment, the thickness and size of the upper panel is preferably adjusted selectively.

In this embodiment, the depth of the upper groove is preferably adjusted selectively.

In this embodiment, the number of the above panels is preferably 2 to 4.

In this embodiment, the cross section of the rotating rod is polygonal, particularly circular.

In this embodiment, the material of the panel, the structure and the rotating rod is preferably wood or resin material.

One preferred embodiment of the reverberation device according to the present invention is applied to the variable diffusion device described above,

The above panel is made of a material that functions as a reflective surface,

A plurality of sound absorbing surfaces attached to the opposite side of the reflecting surface so as to be integral with the reflecting surface;

It is characterized by further comprising.

In this embodiment, it is preferable to adjust the sound absorption rate high so as to dry the reverberation of the gastric diffusion space when the sound is negative.

In this embodiment, it is desirable to adjust the sound absorption rate low so that the reverberation of the gastric diffusion space is appropriate sounding when the sound is music.

In this embodiment, the thickness of the plurality of sound absorbing surface is preferably different.

The variable deflecting device of the present invention can reduce the installation area of the sound absorbing device by selectively changing the opening ratio and the inlet length of each of the sound absorbing plate with the thickness of the air layer behind the sound absorbing plate. The loss rate of the indoor space can be reduced.

1 is an exploded perspective view of a preferred embodiment of an active sound absorbing device according to the present invention.

Figure 2 is an exploded perspective view of another preferred embodiment of the variable sound absorbing portion of the active sound absorbing device according to the present invention.

3 is an exploded perspective view of still another preferred embodiment of the variable sound absorbing portion of the active sound absorbing device according to the present invention.

4 is a partial cross-sectional view of FIG. 3.

Figure 5 is a cross-sectional configuration of another preferred embodiment of the aperture ratio adjustment plate of the active sound absorbing device according to the present invention.

Figure 6a is a perspective view of a preferred embodiment of the variable diffusion device according to the present invention, Figure 6b is a perspective view of the rotating rod of Figure 6a.

7 is a perspective view of another preferred embodiment of a variable diffusion device according to the present invention.

9 is a perspective view of yet another preferred embodiment of a variable diffusion device according to the present invention.

FIG. 10 is a perspective view of a preferred embodiment of the reverberation adjusting device according to the present invention having the reflection surface and the sound absorption surface attached to FIG. 6.

11 is a characteristic curve of a sound absorbing surface and a reflecting surface according to the apparatus of FIG. 10.

FIG. 12A is a reverberation characteristic curve when reverb is adjusted according to the apparatus of FIG. 10, and FIG. 12B is a diagram illustrating an adjustment state of music data adjusted to sound that is sounded appropriately to sound data adjusted to dry sound.

10: housing 20: guide

30: variable sound absorbing part 31: punching part

32: Volume Control Plate 33: Slide Guide

34: aperture

ratio adjusting plate

35, 35a, 35b, 35c: exposed part

36: protrusion 36 ': groove

40: variable diffusion device 41: panel

42: rotating rod 43: groove

44: sound absorption surface 45: reflective surface

46: structure 47: reverberation device

The present invention is directed to a theater reverberation tuning technique. In particular, the present invention relates to a frequency response controller and a variable diffusion device using a Helmholtz resonator, which is a kind of active sound absorbing device capable of adjusting the sound absorbing frequency band. These two devices are closely related to each other and should be understood to constitute a group of inventions that constitute a frequency response controller according to the present invention. Each of these will now be described in detail with reference to various embodiments below.

I. Frequency Response Controller

Hereinafter, the configuration and operation principle of the frequency response controller according to the present invention will be described in detail with reference to FIGS. 1 to 5.

1 is an exploded perspective view of a preferred embodiment of a frequency response controller according to the present invention. Referring to FIG. 1, the frequency response controller according to the present invention includes an enclosure 10 having one surface open, and a surface side which is located inside the enclosure 10 and faces an open surface from this open surface. The guide portion 20 and the guide portion 20 move along the guide portion 20 to vary the volume inside the enclosure portion 10 and to change the aperture ratio of the perforated portion communicating with the outside space of the enclosure portion 10. It is configured to include a variable sound absorbing portion 30.

First, the housing portion 10 has a structure of a hollow cube with a portion of the side open. In the installed state, this open face of the enclosure 10 faces the opposite side of the wall. The enclosure 10 may be made of various materials such as wood, resin, and is preferably sealed except for this open surface to prevent air from passing through.

The inner side of the enclosure 10 is a variable corresponding to the internal volume V in the Helmholtz resonator theory. Equation 1 below is the resonant frequency of the Helmholtz resonator.

Equation 1

Where V is the volume of the resonator, l is the length of the resonator inlet, A is the cross-sectional area of the resonator inlet, d is the diameter of the resonator inlet, and f is the resonant frequency of the Helmholtz resonator.

Referring to Equation 1, when the resonant frequency of the resonator coincides with the external sound, air is quickly reciprocated into and out of the resonator at the inlet of the resonator, and in the process, the air is rubbed with the tube wall of the resonator to be converted into thermal energy. . Therefore, the sound of the frequency can be absorbed.

The inner space of the enclosure portion 10 becomes V in Equation 1, and the interior space of the enclosure portion 10 is formed between the open surface of the enclosure portion 10 and the surface facing the open surface along the guide portion 20. Adjustable by the variable sound absorbing portion 30 to move. The side facing this open side is the side facing the wall.

The guide part 20 may be a groove or a protrusion provided inside the housing part 10, and may be formed by attaching a separate member. As can be seen in Equation 1, as the volume of the inner space of the enclosure 10 increases, the resonance frequency is lowered, and as the volume decreases, the resonance frequency is increased.

The variable sound absorbing portion 30 is provided with a plurality of perforations (31). As will be described in more detail later, the perforations 31 may have a circular or slit structure. This perforation part 31 corresponds to the cross-sectional area of the resonator inlet, which is A in this equation (1).

These perforations 31 is preferably a 3mm diameter circular through hole, the pitch between the holes is suitable 96mm, but this may vary depending on the overall size of the enclosure (10).

The variable sound absorbing portion 30 is provided with a volume adjusting plate 32 provided with a punching portion 31, the volume adjusting plate 32 is moved along the guide portion 20, the inside and the volume of the housing 10 The volume of the space formed by the rear surface of the adjusting plate 32 is adjusted.

For this movement, the volume adjusting plate 32 is provided with a projection 36 engaged with the guide portion 20. The protrusion 36 is applied when the guide portion 20 is in the shape of a groove. On the contrary, when the guide portion 20 has a protruding structure, the volume adjusting plate 32 is attached to the guide portion 20. A groove 36 'to be engaged is provided.

In addition, in the present invention, the guide part 20 is not necessarily a necessary component, and a state in which the volume adjusting plate 32 having the same size as the open surface of the enclosure part 10 is inserted into the enclosure part 10. Because the volume control plate 32 can be combined without falling or displaced without the action of external force, and when changing the sound absorption frequency (resonance frequency) can be moved to a suitable position by applying force from the outside .

In FIG. 1, the volume adjusting plate 32 is configured to be movable in the x-axis direction. As described above, the present invention can widen the band of the sound absorption frequency by changing the volume of the internal space of the frequency response controller (sound absorber), and can be applied regardless of whether the installation place is narrow by miniaturizing the sound absorber.

Second Embodiment

2 is an exploded perspective view of another preferred embodiment of the frequency response controller according to the present invention. The same parts as in the first embodiment will be omitted. Referring to FIG. 2, the variable sound absorbing portion 30 according to another embodiment of the present invention has a slit structure in which the perforation portion 31 provided in the volume adjusting plate 32 is vertically long, and the perforation portion 31 is formed. It may be formed in the same number as the aperture ratio adjusting plate 34 or the number of aperture ratio adjustment plates 34 or more.

In addition, the slit-type exposed part 35 having the same shape as the above punched part 31 is also provided in the aperture ratio adjusting plate 34 which is in close contact with the entire surface of the volume adjusting plate 32 and is movable in the left and right (y-axis directions).

The variable sound absorbing portion 30 according to another embodiment of the present invention having such a configuration uses a volume adjusting plate 32 that can move in the x-axis direction from the inside of the housing portion 10 to the volume inside the housing portion 10. The sound absorption frequency can be changed in accordance with the change of. The slit-type exposed portion 35 provided in each aperture ratio adjustment plate 34 is moved by moving each of the aperture ratio adjustment plates 34 in the y-axis direction. By adjusting the positional relationship of the slit-type perforations 31, the sound absorption frequency may be changed by adjusting the cross-sectional area of the inlet.

The perforations 31 of the volume adjusting plate 32 and the exposed portion 35 of the aperture ratio adjusting plate 34 may be the same in shape and size, and may be different in shape and size as necessary.

Third Embodiment

3 is an exploded perspective view of a variable sound absorbing unit according to another exemplary embodiment of the present invention, and FIG. 4 is a partial cross-sectional view of FIG. 3. Here, the description of the same parts as in the first embodiment is omitted. 3 and 4, the other configuration is the same as that of FIG. 2, but the shape of the aperture adjustment plate 34 is changed to adjust the aperture ratio of the perforated portion 31 of the volume adjustment plate 32, and To adjust the thickness of the perforations 31.

The thickness of the perforation part 31 is a value corresponding to the length of the inlet represented by l in this equation (1). That is, the opening ratio adjusting plate 34 may be made thicker than the periphery where the exposed part 35 is formed, and when the exposed part 35 coincides with the perforated part 31, the air flows. The length of the inlet is changed to change the sound absorption frequency.

Fourth Embodiment

5 is a cross-sectional configuration diagram of another embodiment of the aperture ratio adjustment plate. Here, the description of the same parts as in the first embodiment is omitted. Referring to Fig. 5, the aperture ratio adjustment plate 34 is provided with a plurality of exposed

portions

35a, 35b, and 35c, and the aperture ratio adjustment plate 34 is left and right so as to have a difference in depth of each exposed

portion

35a, 35b, 35c. The thickness of the furnace can be configured to be different. Therefore, according to the exposed

portions

35a, 35b, and 35c coinciding with the perforated portion 31, l, the inlet length described above, is varied so that the sound absorption frequency can be changed.

The present invention described above may be installed on a wall surface, and in particular, may be installed on the entire wall as one of the examples described above, but may be installed in combination of all the above-described embodiments. The combination of all such embodiments makes it easy to finely adjust and adjust the sound absorption frequency, and can be arranged according to the user's taste to obtain an interior effect.

In addition, the aperture ratio adjusting plate 34 of the variable sound absorbing portion 30 applied to one enclosure 10 may not be all the same shape, and the aperture ratio adjusting plate 34 having the shape of another embodiment described above may be mixed. .

II. Variable diffuser

Hereinafter, the configuration and operation principle of the variable spreading device of the frequency response controller according to the present invention will be described in detail with reference to FIGS. 6 to 12.

A variable diffusion device according to the present invention will now be described with reference to FIGS. 6 and 9. One preferred embodiment of the variable diffusion device 40 according to this invention makes the attenuation pattern of the reflected sound relative to the direct sound in a given spreading space decay exponentially,

Over time, the surface of the diffuser is formed into a polygon to prevent flutter echoes and to maintain the interaural cross-correlation (IACC) value of 0.5 or less without sacrificing sound clarity. IACC represents the similarity of the sound reaching the listener's left and right ears and is used to confirm the coincidence of the reflected sound on both sides of the venue.

Here, the polygonal diffuser has a triangular or elliptical structure and the relationship between the horizontal length (a) and the height (b) of the diffuser is shown in Equation 2.

Equation 2

At this time

Is a wavelength of sound to be absorbed.

In the variable diffusion device 40 of the present invention,

A plurality of rotating planar panels 41;

One end of the upper panel 41 is fixed to the rotating rod 42 to serve as a rotating shaft to rotate;

A plurality of grooves 43 formed longitudinally by the width and length of the panel 41 so that one end of the panel 41 is fixed to the rotary rod 42;

Sound absorbing surface 44 formed on one side of the upper panel 41;

A reflective surface 45 formed on the panel surface opposite to the upper sound absorbing surface 44;

The plurality of panels 41 have a height and horizontal and vertical width that can be rotated in one direction of the rotating rod 42 while being attached to the rotating rod 42, and made of a bottom and a ceiling surface so that the rotating rod 42 is fixed. The front surface has an open hexahedral shape and includes a structure 46 for accommodating the upper panel 41 and the rotating rod 42 and emitting a diffused sound to the front portion.

In this invention, the thickness and size of the upper panel 41 can be arbitrarily changed as necessary. In the performance experiment of this invention, a panel having a thickness of 12 mm, a height of 300 mm, and a width of 140 mm was used.

In addition, in this invention, the depth of the upper groove portion 43 into which the upper panel 41 is fitted to the upper rotating rod 42 may be arbitrarily changed as necessary. In the performance experiment of the present invention, the rotating rod 42 having a depth of 20 mm is Was used.

And in this invention, it is preferable that the number of the upper panels 41 is 2-4.

In this invention, the cross-section of the rotary rod 42 is polygonal, in particular preferably circular.

In particular, in this invention, in order to make the reverberation of the above diffusion space into a dry sound when the sound is negative, it is preferable to adjust the resonator inlet area appropriately. In addition, it is preferable to adjust the resonator inlet area appropriately so that the reverberation of the above diffusion space is a live sound when the sound is music.

And the material of the upper panel 41, the structure 46 and the rotating rod 42 in this invention is preferably made of wood or resin material.

FIG. 10 shows the sound absorbing surface 44 attached to the front surface of the panel 41 of the variable diffusion device 40 of FIG. 6 and performs the function of the reverberation device 47. The sound absorbing surface 44 may also be attached to the variable diffusion device 40 of FIGS. 7 to 9 to configure the reverberation device 47.

The sound absorbing surface 44 used in FIG. 10 may be made of, for example, a polyester sound absorbing material having a thickness of 30 mm. 10 shows a case where the panel 41 itself is used as the reflecting surface 45.

11 is a graph comparing the characteristics of the suction surface 44 and the reflective surface 45. The data on this graph is FFT data (fast Fourier transformation data), the horizontal axis is the audible frequency band of the FFT data, and the vertical axis is the magnitude of the signal. Although the characteristics of the sound absorbing surface 44 and the reflecting surface 45 are similar in general, it is observed that the signal value of the reflecting surface 45 (indicated by a small circle on the graph) is slightly larger in the end. In the region, it was observed that the value of the sound absorbing surface 44 became slightly larger and then gradually became smaller than the reflecting surface 45. This graph shows that the sound absorption characteristics change according to the size of the cross-sectional area of the resonator inlet.

Fig. 12 shows an example in which reverberation in the hall for voice and music data is adjusted by the reverberation adjusting device of the present invention. 12 shows an example in which the reverberation is adjusted to the sound of the voice intelligibility center with respect to the voice data, and the right side shows an example in which the reverberation is adjusted to the sound of the music intelligibility with ringing with respect to the music data. As shown in this example, the reverberation adjusting device of the present invention leads to the conclusion that the reverberation can be adjusted according to the listening preference of the listener, and the hall can be used for various purposes according to the event. In the right graph of FIG. 12, the phenomenon in which the reverberation decreases almost exponentially is determined, and it is determined that the left side also shows an exponential decrease. It is well known that the ideal reflection pattern attenuates exponentially in the ideal diffusion space, which is believed to correspond to this invention.

In particular, in Figure 12 it was confirmed that there is no echo effect in the present invention, the flutter echo (Flutter echo) does not occur also proved that the present invention has a very excellent function. In the case of the present invention, it was also confirmed that the IACC value was maintained at 0.5 or less to secure a desirable sound field.

Due to the implementation of the present invention, both side walls are parallel and hard wall echoes can be prevented, a phenomenon in which clapping or footsteps, etc. are reflected by multiple reflections can be prevented, and sound that is shuffled can be prevented.

In addition, the present invention can selectively change the area of the inlet and the length of the inlet as well as the internal volume of the sound absorbing device, it is possible to precisely adjust the desired sound absorption frequency, so that the sound absorption frequency band can be expanded in the same space do.

In addition, the implementation area of the present invention can reduce the installation area of the sound absorbing device, and as a result, the loss rate of the indoor space can be reduced.

As such, the present invention may be variously modified and may take various forms, and only the specific embodiments thereof are described in the detailed description of the present invention. It is to be understood, however, that the invention is not limited to the particular forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

Claims

An active sound absorption device, characterized in that the band of sound absorption frequencies is widened by varying the volume of the device internal space and the resonator inlet area.
In claim 1,

A hollow housing having one side surface open; And

A variable sound absorbing part inserted into the upper housing part to move inside the housing part to adjust an internal volume of the housing part and to adjust an opening ratio of a perforating part communicating the inside and the outside of the housing part;

Characterized in that comprises, active sound absorbing device.
The method of claim 2, wherein the variable sound absorption unit,

A volume and resonator inlet area adjusting plate inserted into the housing and variably adjusting the internal volume and the resonator inlet area of the housing according to a position adjustment;

An active sound absorption device, characterized in that provided with.
[4] The apparatus of claim 3, further comprising an exposed portion consisting of a plurality of perforations at a position facing the perforated portion of the volume and the resonator inlet area adjusting plate, the position being adjusted in close contact with the front surface of the volume adjusting plate, Opening ratio adjusting plate for adjusting the opening ratio of the above-mentioned perforations;

It further comprises, active sound absorbing device.
The active sound absorbing device of claim 2, wherein the perforations are a plurality of circular or slit through holes, the diameter of which is selectively varied, and the pitch between the holes varies according to the overall size of the enclosure.
The active sound absorbing device of claim 4, wherein the aperture control plate is provided in plural numbers, and the thickness of each aperture control plate is different from the depth of the exposed portion.
5. The active sound absorbing device of claim 4, wherein a plurality of upper exposed portions are provided in the opening ratio adjusting plate, and the depths of the exposed portions are different from each other.
The active sound absorbing device of claim 2, further comprising a guide part configured to move the variable sound absorbing part inside the gas container part.
The active sound absorbing device of claim 8, wherein the guide part is one formed by attaching a groove, a protrusion, or a separate member provided inside the upper housing part.
5. The active sound absorbing device of claim 4, further comprising a slide guide at a front edge of the volume and resonator inlet area adjusting plate to move the aperture control plate in close contact with the volume and the resonator inlet area adjusting plate. .
The volume adjusting plate of claim 8, wherein the volume and the resonator inlet area adjusting plate are provided with protrusions engaging with the upper guide part when the upper guide part is in the shape of a groove, and the volume adjusting plate when the guide part is projected by the protrusion or attaching a separate member. It is characterized in that the groove is engaged with the upper guide portion, active sound absorbing device.
This results in the attenuation pattern of the reflected sound for the direct sound in a given spread space being exponentially attenuated.

Over time, the surface of the diffuser is formed into a polygon to prevent flutter echoes and maintain IACC values of 0.5 or less without sacrificing sound intelligibility.

The polygonal diffuser has a triangular or oval structure and the relationship between the width (a) and height (b) of the diffuser

While maintaining

At this time
Is a wavelength of sound to be absorbed, the variable diffusion device.
In claim 12,

A plurality of flat panels;

One end of the upper panel is fixed to the rotating rod to serve as a rotating shaft to rotate;

A plurality of grooves formed longitudinally by the width and length of the panel so that one end of the panel is fixed to the rotary rod;

The plurality of panels are attached to the rotating rod with a height, horizontal and vertical size that can rotate in one direction of the rotating rod, and consists of a bottom and a ceiling surface to fix the rotating rod, and the front part has an open hexahedral shape. A structure accommodating the panel and the rotating rod and emitting a diffused sound to the front portion;

A variable diffusion device comprising: a variable diffusion device.
The variable diffusion device of claim 13, wherein the thickness and size of the panel is selectively adjusted.
The variable diffusion device of claim 13, wherein the depth of the upper groove is selectively adjusted.
14. The variable diffusion device of claim 13, wherein the number of panels is from 2 to 4.
14. The variable diffusion device of claim 13, wherein the cross section of the rotating rod is polygonal, in particular circular.
14. The variable diffusion device of claim 13, wherein the panel, the structure, and the rod are made of wood or resin.
In a variable reverberation apparatus to which the variable diffusing device value of one of claims 12 to 18 is applied,

The above panel is made of a material that functions as a reflective surface,

A plurality of sound absorbing surfaces attached to the opposite side of the reflecting surface so as to be integral with the reflecting surface;

It further comprises a variable reverberation device.
20. The variable reverberation apparatus according to claim 19, wherein the reverberation rate of the upper diffusion space is adjusted so as to dry the reverberation of the gas diffusion space when the sound is negative.
20. The variable reverberation apparatus according to claim 19, wherein the reverberation of the upper diffusion space is adjusted so that the sound absorption rate is lowered so that the sound is appropriate when the sound is music.
The variable reverberation apparatus of claim 19, wherein the thicknesses of the plurality of sound absorbing surfaces are different from each other.