JPH061001B2 - Reverberation variable device - Google Patents

Description

The present invention relates to a reverberation variable device configured so that the reverberation time of a listening room or a room such as a hall can be changed.

[Conventional technology]

Heretofore, various types of reverberation varying devices have been known (references cannot be cited).

For example, the one shown in FIG. 8 (a) has a portion (G ') having a high sound absorption coefficient formed on the inner surface (I') of the chamber and a sliding door (1 ').
It is a combination of and. In other words, when this door (1 ') is pulled in and positioned as shown by the broken line in the figure,
The part (G ') with a high sound absorption coefficient is exposed to the room (C'), the sound absorption is increased, and the reverberation time of the room (C ') is shortened. On the other hand, when this door (1 ') is pulled out and positioned as shown by the solid line in the figure, the part (G') with a high sound absorption coefficient is
Since the surface (P ') of this door (1'), which is covered with (1 ') and has a high reflectance, faces the room (C') instead,
Sound absorption is low and reverberation time is long.

Further, for example, as shown in FIG. 8 (B), a part of the inner surface (I ′) of the chamber (C ′) is a movable body which is rotatable around an axis (Z ′).
(1 ″). This movable body (1 ″) has one side
(G ′) is made of a material having a high sound absorption coefficient, and the other surface (P ″) is made of a material having a high reflectance coefficient.
Rotate (1 ″) so that either surface (G ″) or (P ″) is a chamber
By positioning it so that it faces (C ′), the sound absorption is high and the reverberation time of the room (C ′) is short and the sound absorption is low.
Either state of (C ′) with long reverberation time can be displayed.

[Problems to be solved by the invention]

However, in the case of the above-described conventional configuration, there is a problem as described below, and there is room for improvement.

First, in the case of changing the reverberation time, FIG.
The method shown in (a) requires the operation of opening and closing the door (1 '), and the method shown in FIG. 8 (b) requires the operation of opening and closing the movable body (1 "). Then, in any case, this operation is performed in a state where it is directly visible from the inside of the chamber (C ').

On the other hand, a psychoacoustic experiment is often conducted in a listening room or a room (C ′) such as a hall. This includes, for example, investigating the relationship between changes in reverberation time and intelligibility, and subjectively evaluating the sound field due to changes in reverberation time. Therefore, when performing such a psychological experiment, the reverberation variable operation in the directly visible state as described above is not preferable because it may give a visual psychological effect to the subject. In order to eliminate such a psychological effect, it is possible to completely darken the room (C ′), but the procedure of the experiment may become complicated.

Secondly, the sound absorbing material generally has a low sound absorption coefficient in the low sound range and high characteristics in the high temperature range, especially in the porous type which is often used for the finishing part of the chamber (C '). Is what you have. Therefore, in the case of the conventional structure in which the sound absorbing material having such characteristics is formed on a part of the inner surface of the room, there is a possibility that the reverberation time cannot be changed with a sufficient width in the low sound range. It was

In view of the above situation, an object of the present invention is to provide a reverberation variable device,
The object of the present invention is to reduce the visual impact on subjects such as hearing experiments and the like, and to improve the reverberation time change characteristic in the entire audible frequency band.

[Means for solving problems]

A characteristic configuration of a reverberation variable device for changing reverberation time of a room according to the present invention is that a part of a wall, which forms a space communicating with the room by an opening, and which is a wall partitioning the space from the room, is seen from the back side. In addition, the sound absorbing force changing device for changing the inner surface of the space between the state of high sound absorption and the state of high reflectance is provided.

[Action]

In other words, since the operation of changing the sound absorption force changing device for changing the reverberation time is performed on the back side of the wall when viewed from the room, for example, when performing a hearing experiment, this operation may be directly visible to the subject in the room. Few.

Furthermore, since the space in which the sound absorbing force changing device is arranged functions as a resonator by itself, it is possible to enhance the sound absorbing force in the low temperature range.

〔The invention's effect〕

As a result, for example, at the time of an auditory experiment, it is possible to reduce the visual influence on the subject without performing processing such as completely darkening the room, without complicating the experimental procedure. Now you can improve the accuracy of. Also, the reverberation time can be changed over a wide range from the high temperature region to the low tone region while maintaining good linearity. Therefore, as a whole, it is possible to provide a reverberation variable device that enables highly accurate hearing experiments and has excellent reverberation change characteristics.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are a plan view and a sectional view, respectively, of a room (C) to which the reverberation variable device according to the present invention is applied. Audition room
(C) is a pentagon with no parallel wall surface in plan view to prevent flutter echo. And the listening room
Seven wall type sound absorbing units (X) are formed around (C) as an example of the reverberation variable device according to the present invention. Further, two ceiling type sound absorbing units (Y) are formed on the ceiling.

The ceiling type sound absorbing unit (Y) has a space (w) formed in the ceiling pocket,
It consists of a sliding door (2) that can be opened and closed with respect to the opening (b) between this space (w) and the listening room (C). Glass wool (G ₃ ) is stretched around the inner surface of the space (w). The upper surface of the sliding door (2) is affixed with glass wool (G ₄ ), and the lower surface (P ₂ ) of this door ( ₂ ) is affixed with plaster board. In other words, when this sliding door (2) is retracted, the high sound absorbing parts (G ₃ ) and (G ₄ ) forming the space (w) are exposed in the listening room (C), and the sound absorbing power is increased. The higher the value, the shorter the reverberation time in the listening room (C). On the other hand, when this door (2) is pulled out, the space (w) and the listening room (C) are cut off, and this door (2)
The surface (P ₂ ) with a relatively high reflectance of is exposed in the listening room (C),
The sound absorption is low and the reverberation time in the listening room (C) is long.

Next, the wall type unit (X) will be described. FIG. 3 shows the plane of the unit (X), and FIG. 4 shows the cross section of the unit (X).

Each unit (X) has a space (v) that communicates with the listening room (C) through the opening (a), and there are two on the wall forming this space (v) and one on the ceiling surface, for a total of three. Sound absorption changer
It has (A). In this embodiment, the sound absorbing force changing device (A) is a door (1) which is rotatable and fixable around the shaft cores (Z ₁ ) to (Z ₃ ). The surface on one side of this door (1) is formed in a glass wool layer (G ₁ ) having a relatively high sound absorption coefficient, and the surface on the other side (P ₁ ) has a relatively high reflectance coefficient. It has a high plaster board. Also, adjacent units
The space between (X) and the ceiling pocket of each unit (X) are filled with 32 kg / m ³ of glass wool (G ₂ ). And, the door (1) of each unit (X) is in the open state positioned as shown by the solid line in the figure, the surface of the filled glass wool (G ₂ ), and the glass wool layer (G ₁ ) of the door (2) itself. However, so as to be a part of the inner surface of this space (v), and in a closed state positioned as shown by the two-dot chain line in the figure, while covering the filled glass wool (G ₂ ) by the door (1) itself. , The plasterboard pasting surface (P ₁ ) is configured to be a part of the inner surface of this space (v). That is, when the door (1) is opened, the sound absorption by the unit (X) becomes large and the reverberation time in the listening room (C) becomes long. Further, when the door (1) is closed, the sound absorption by the unit (X) becomes small and the reverberation time in the listening room (C) becomes long. Further, as shown in FIG. 5, each door (1) is provided with an air cylinder (3) for performing a closing operation, which continuously changes the operation amount of this air cylinder (3). By that door (1)
The sound absorption of the unit (X) can be changed steplessly by changing the opening of.

And, as shown in FIG. 1, FIG. 3 and FIG.
(1) is attached to the back side of the wall (4) that separates the space (v) that composes the wall-type sound absorbing unit (X) from the listening room (C) when viewed from the listening room (C). Opening and closing each door (1) is also possible with this wall (4)
It is supposed to be done behind the scenes. In other words, the listening room
From inside (C), it is difficult to see the opening and closing of this door. Therefore, when conducting a hearing experiment or the like in the listening room (C), the opening / closing operation of each door (1) to change the reverberation time may be given as visual information to the subject in the listening room (C). It is possible to carry out the experiment with high accuracy.

FIG. 6 is a graph showing the frequency characteristic of the sound absorbing force per one of the wall type sound absorbing units (X). The horizontal axis is the center frequency (Hz) of the 1/3 octave band noise used for measurement,
The vertical axis represents the sound absorption force (m ² ) represented by (S ·) where (S) is the inner surface area and () is the average sound absorption coefficient. As can be seen from this graph, the sound absorbing power of this unit (X) is relatively high in the low sound range (63 Hz to 250 Hz). It is considered that this is because the space (v) of this unit (X) functions as a resonator.

As shown in FIG. 1, the listening room (C) is provided with a control device (5) for controlling the operation of the air cylinders (3) of the units (X) and (Y), and the doors By arbitrarily setting the opening of (1), the reverberation time of the listening room (C) can be arbitrarily set within a variable range. Further, the control device (5) is connected to a personal computer (6) arranged outside the listening room (C), and each door (1), (2) required to obtain a necessary reverberation time. The opening degree of is obtained by this personal computer (6) and transferred to the control device (5),
All doors (1) and (2) can be moved automatically.

Further, FIG. 7 shows that the doors (1) and (2) of the wall type sound absorbing unit (X) and the ceiling type sound absorbing unit (Y) are shown in the listening room (C) in the fully opened state and the fully closed state. It is a graph which shows the frequency characteristic of reverberation time. The horizontal axis is the center frequency (Hz) of the 1/3 octave band noise used for the measurement. As can be seen from this graph, a reverberation time variable state with a sufficient width can be obtained over almost the entire frequency band between the fully closed state indicated by the white circle in the figure and the fully opened state indicated by the black circle in the figure. . That is, it can be seen that the variable characteristic of the reverberation time in the low sound range is improved due to each wall-type sound absorbing unit (X) having a high sound absorbing power in the low sound range. The listening room
Floor area of (C) is 22.7 m ² , volume is 56.7 m ³ , surface area is 93.9 m ^2.
Is. For the walls and ceiling of the listening room (C), plaster board (12 mm) is placed on a calcium silicate board (8 mm), and vinyl cloth is placed on it, and 32 kg / m ³ is placed inside the ceiling substrate. 50 mm of glass wool and 32 mm / m ³ of glass wool of 75 mm are filled in the wall foundation. Audition room
In the floor of (C), a plywood (5.5 mm) is attached on a flooring (15 mm), a carpet (7 mm) is laid on it, and the underfloor space is filled with 32 kg / m ³ of glass wool.

As the sound absorbing force changing device (A), in place of the single-opening type door (1) in the above-described embodiment, a single pulling type door, a surface made of a material having a high sound absorption coefficient and a material having a high reflectance are used. It is possible to use various things such as a movable body having a surface made of. Further, as the material having a relatively high sound absorption coefficient, in addition to glass wool, rock wool, soft urethane foam, etc., and as the material having a relatively high reflectance, various materials such as plasterboard, asbestos lux and metal plates are used. It can be used.

The shape and specific dimensions of the space (v) and the opening (a) that make up the reverberation variable device (X), or the number and arrangement of the reverberation variable devices (X) should be within the required reverberation time variable range. It can be changed as appropriate. In addition, ceiling type sound absorbing unit
(Y) may be in the form of a reverberation variable device according to the present invention.

The present invention can be applied not only to the listening room (C) but also to various halls and studios, auditoriums, gymnasiums, etc., which are collectively referred to as room (C).

[Brief description of drawings]

1 to 7 show an embodiment of a reverberation variable device according to the present invention. FIG. 1 is a plan view of a listening room, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. FIG. 4 is a plan view of the reverberation variable device, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, FIG. 5 is an enlarged view of the sound absorbing force changing device portion, and FIG. 6 is a graph showing the sound absorbing force characteristics of the reverberation variable device. FIG. 7 is a graph showing the reverberation time characteristics of the listening room. 8 (a) and 8 (b) are plan views corresponding to FIG. 3 showing a conventional example, respectively. (C) …… room, (v) …… space, (a) …… opening, (4) …… wall,
(A) …… Sound absorption change device.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masashi Fujimoto, 683, Hirao, Mihara-machi, Minamikawachi-gun, Osaka Prefecture Takenaka Corporation Technical Research Institute, Osaka Branch (72) Kunihiko Araki, 683, Hirao, Mihara-cho, Minamikawachi-gun, Osaka Takenaka Corporation Technical Research Institute Osaka Branch

Claims (1)

[Claims] 1. A reverberation variable device configured to change the reverberation time of a room (C), the space (v) communicating with the room (C) by an opening (a). Forming this space
The inner surface of this space (v) spans the state of high sound absorption and the state of high reflectance in the portion on the back side as viewed from the chamber of the wall (4) that separates (v) from the chamber (C). A reverberation variable device provided with a sound absorbing force changing device (A) to be changed.