JP5602039B2 - Sound masking system - Google Patents

Description

  The present invention relates to a sound masking system.

  Conventionally, a sound masking system has been known as a system that reduces the clarity of unnecessary speech in a room and the clarity of conversation that requires privacy (see, for example, Patent Documents 1 and 2). The sound masking systems described in Patent Documents 1 and 2 are so-called ceiling concealed sound masking systems in which speakers are arranged upward in a double ceiling in a room and masking sounds are emitted from the speakers. The masking sound emitted upward from the speaker is reflected and diffused by the upper wall in the ceiling, and is emitted into the room through the ceiling. Thus, in the sound masking systems described in Patent Documents 1 and 2, all areas under the ceiling are masked equally.

  The ceiling masking type sound masking system is designed so that the speaker as the sound source cannot be seen by the user, so it has excellent aesthetics, and the user cannot recognize the exact position of the sound source, thus realizing effective masking. be able to.

JP 2003-216164 A JP 2002-194836 A

  By the way, as a physiological characteristic of human beings, there is a tendency to unconsciously increase the volume of utterance when talking in a noisy environment, and unconsciously to reduce the volume of utterance when talking in a quiet environment ( Lambert effect). In conventional sound masking systems, since the masking sound reaches the speaker, the voice of the speaker is unconsciously increased due to the Lambert effect. As a result, the privacy of the conversation cannot be secured, Noise may not be suppressed.

  Therefore, the present invention has been made to solve such technical problems, and an object thereof is to provide a sound masking system capable of providing an appropriate sound environment for each area.

  That is, the sound masking system according to the present invention is a sound masking system that outputs a masking sound to a room, and includes a ceiling and a speaker that is disposed in a space behind the ceiling and outputs the masking sound, and includes a target area and a non-target area. Among the indoor areas divided into areas, a sound insulation layer for insulating the masking sound is disposed in the space behind the ceiling of the target area.

  In the sound masking system according to the present invention, the indoor area is divided into a target area and a non-target area, and a sound insulating layer that blocks masking sound is disposed in the space behind the ceiling of the target area. For this reason, the masking sound from the ceiling to the target area is sound-insulated by the sound insulation layer and is not output into the target area, and the masking sound from the ceiling to the non-target area easily reaches the non-target area. In this way, it is possible to selectively set the area for outputting the masking sound.

  Here, the ceiling may be formed using a fine perforated plate. By forming the ceiling of the indoor area using the fine perforated plate, the masking sound can easily pass through the area of the ceiling where the sound insulation layer is not disposed.

  The sound insulation layer may be disposed at a position spaced from the ceiling. In this way, by arranging the sound insulation layer behind the fine perforated plate forming the ceiling of the target area and spaced from the fine perforated plate, there is an air layer between the fine perforated plate and the sound insulating layer. It is formed. In this case, the ceiling of the target area is configured as a mass-spring vibration system (single resonance system) in which the air in the perforations is mass and the elasticity of the air layer is a spring, and has sound absorption performance. That is, sound generated in the target area and reaching the ceiling is absorbed by sound energy consumed by internal friction of the single resonance system. For this reason, it is possible to prevent the sound in the target area from reflecting off the ceiling and reaching the non-target area. Furthermore, since the reverberation is suppressed by absorbing sound from the ceiling surface, the target area can be made an environment where it is easy to speak.

  According to the present invention, it is possible to provide an appropriate sound environment for each area.

1 is a schematic diagram of a sound masking system according to an embodiment of the present invention. It is an example of application of the sound masking system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  The sound masking system according to this embodiment is a so-called ceiling concealed type sound masking system, which is suitable for controlling the sound environment of a relatively large space such as a waiting room facing a drug counter in an open plan office or a hospital. Is adopted.

  First, an environment to which the sound masking system according to this embodiment is applied will be described. FIG. 1 is a top view of an office space. As shown in FIG. 1, the indoor area of the open plan office is divided according to the purpose. For example, the indoor area is divided into a meeting area (speaker area) A for mainly performing meetings and meetings, and an office area (listener area) B for mainly performing office work. The meeting area A and the work area B are arranged adjacent to each other and are located below the same ceiling surface. The meeting area area A and the work area B are conceptually partitioned, and not only when there is a partition such as a low partition or a high partition, but also when there is a hanging wall extending from the ceiling to the floor, or , There may be no partition at all.

  Next, the configuration of the sound masking system according to this embodiment will be described. FIG. 2 is a schematic diagram of the sound masking system 1 according to the present embodiment. In consideration of ease of understanding, the case where the meeting area A and the work area B are partitioned by the low partition 15 will be described as an example here.

  As shown in FIG. 2, in the sound masking system 1, the speaker 10 is disposed above the ceiling 12 suspended from the slab 16, that is, behind the ceiling. As shown in FIG. 1, a plurality of speakers 10 may be arranged according to the size of the masking target range. The speaker 10 is arranged so as to output a masking sound upward. The speaker 10 is connected to a control unit 11 that controls the type and volume of the masking sound. The control unit 11 outputs sound for sound masking from the speaker 10. Sound masking sounds include, for example, those that simulate air conditioning noise as in the past, broadband noise that is adjusted in consideration of the auditory masking mechanism, information masking sounds that are synthesized by processing irrelevant speech, Music or the like is employed and is not limited to these.

  The ceiling 12 is formed using a fine perforated plate. The micro perforated plate is a plate having a plurality of micro holes penetrating from one main surface to the other main surface. For example, a plate in which holes having a diameter of 0.5 mm are formed at a pitch of 4 to 5 mm. Further, in the space behind the ceiling of the meeting area A, the sound insulation layer 14 is arranged in parallel at a position away from the ceiling 12. For this reason, the meeting area area A and the work area B are conceptually divided, but structurally, the meeting area A is an area (target area) in which the sound insulation layer 14 is arranged on the back of the ceiling. Yes, the work area B can be defined as an area (non-target area) where the sound insulation layer 14 is not arranged on the back of the ceiling.

  The sound insulation layer 14 may be disposed by being suspended from the slab 16 by a suspension member or the like, or may be supported by a support member or the like disposed on the ceiling 12. The sound insulating layer 14 has a function of insulating the masking sound, and is a plate member having rigidity, for example. As such a sound insulation layer 14, for example, a gypsum board or plywood is used. An air layer 13 is formed between the sound insulation layer 14 and the ceiling 12. The air layer 13 is about 5 cm thick, for example. That is, the ceiling portion of the meeting area A has a three-layer structure including a ceiling 12 made of fine perforated plates, an air layer 13 and a sound insulation layer 14. A Helmholtz resonance mechanism is constituted by the air layer 13 and the fine holes by disposing the sound insulation layer 14 in parallel with a space above the fine perforated plate. That is, it is configured as a mass-spring vibration system (single resonance system) in which the air in the perforations is mass and the elasticity of the air layer is spring. For this reason, the ceiling part of the meeting area A has a sound absorption characteristic. On the other hand, the ceiling portion of the office area B is composed only of the ceiling 12 made of fine perforated plates.

  Next, the effect of the sound masking system 1 according to the present embodiment will be described. A masking sound is output from the speaker 10 by the control unit 11. The masking sound is reflected and diffused by the slab 16 and released to the indoor area. Here, since the ceiling portion of the work area B is composed only of the ceiling 12 made of fine perforated plates, the masking sound is easily transmitted and diffused through the ceiling 12 using the openings. (L1 in the figure). That is, by adopting a fine perforated plate having a higher transmittance than that of a normal ceiling plate, in the work area B, the clarity of unnecessary speech is effectively reduced by the masking sound. That is, a sufficient effect can be obtained even when the output of the masking sound is suppressed.

  On the other hand, since the sound insulation layer 14 is disposed behind the ceiling of the meeting area A, the masking sound output from the speaker 10 is reflected by the sound insulation layer 14 and cannot pass through the ceiling 12 (in the drawing). L2). As a result, the meeting area A can be provided with a clear environment where conversation is easy to perform, and thus it is possible to suppress voice generation. Therefore, the Lambertian effect resulting from the masking sound can be suppressed. That is, it is possible to set the meeting area A as a Lambertian effect suppression area (target area) and the work area B as a background noise control area (non-target area).

  Furthermore, when the utterance sound in the meeting area A reaches the ceiling surface, the sound energy is consumed and absorbed by the internal friction of the single resonance system. For this reason, it is possible to suppress the utterance sound in the meeting area A from reaching the work area B through the ceiling 12. Furthermore, by providing the ceiling 12 of the meeting area A with a sound absorption characteristic, it is possible to provide a space with a short reverberation time. Therefore, since it is possible to provide a clear environment where conversation is easy to perform, voices can be suppressed in the meeting area A.

  As described above, in the sound masking system 1 according to the present embodiment, by arranging the sound insulation layer 14, the sound insulation performance of the ceiling 12 can be differentiated for each area, so that the region for outputting the masking sound is selectively set. It becomes possible to do. For this reason, a masking sound can be output only to the background noise control area without producing a masking sound for the Lambertian effect suppression area.

  Further, in the sound masking system 1 according to the present embodiment, the sound absorption performance of the ceiling 12 can be made different for each area by using the fine perforated plate and the sound insulation layer 14, so that the Lambert effect suppression area is It is possible to provide a space with higher sound absorption than the background noise control area. Therefore, when the Lambertian effect suppression area and the background noise control area are the same volume, the reverberation time can be shortened in the Lambert effect suppression area compared to the background noise control area. Therefore, it is possible to provide an environment where conversation is easy in the Lambertian effect suppression area and an environment with low clarity in the background noise control area.

  Furthermore, in the sound masking system 1 according to the present embodiment, by using the fine perforated plate and the sound insulation layer 14, both the sound insulation function and the sound absorption function can be exhibited with a simple configuration. That is, only by arranging the sound insulation layer 14 behind the fine perforated plate, in the Lambert effect suppression area, the masking sound is blocked by the sound insulation function to suppress the Lambert effect, and the sound absorption function suppresses the sound in the Lambert effect suppression area. Two effects of suppressing reverberation can be exhibited simultaneously. Further, in the background noise control area, the masking sound can be appropriately transmitted using the opening.

  The embodiment described above shows an example of a sound masking system according to the present invention. The sound masking system according to the present invention is not limited to the sound masking system 1 according to the embodiment, and the sound masking system 1 according to the embodiment is modified or changed without changing the gist described in each claim, or It may be applied to other things.

  For example, in the above-described embodiment, the office space has been described as an example, but the present invention is not limited to this. For example, the sound masking system according to the present invention is applied to a waiting room facing a medicine counter in a hospital, and a Lambert effect suppression area is used as a pharmacy counter, and a background noise control area is used as a waiting space, thereby providing an environment in consideration of speech privacy. can do.

  In the above-described embodiment, the case where the ceiling 12 is formed of a fine perforated plate has been described. However, a conventional ceiling material such as a rock wool sound absorbing plate may be used. Further, the sound insulation layer 14 may be disposed behind the ceiling 12 without being separated. Even when configured in this manner, an appropriate sound environment can be provided for each area based on the arrangement position of the sound insulation layer 14.

  Furthermore, although embodiment mentioned above demonstrated the example arrange | positioned in the ceiling so that the speaker 10 may output a sound upwards, it is not restricted to this. For example, the speaker 10 may be disposed in the ceiling so as to output sound downward.

  DESCRIPTION OF SYMBOLS 1 ... Sound masking system, 10 ... Speaker, 12 ... Ceiling, 13 ... Air layer, 14 ... Sound insulation layer, A ... Meeting area (target area), B ... Office area (non-target area).

Claims (3)

A sound masking system that outputs masking sound to the room,
The ceiling,
A speaker that is placed in the space behind the ceiling and outputs a masking sound;
With
A sound insulation layer for insulating the masking sound is disposed in the space behind the ceiling of the target area among the indoor areas divided into the target area and the non-target area,
Sound masking system featuring   The sound masking system according to claim 1, wherein the ceiling is formed using a fine perforated plate.   The sound masking system according to claim 2, wherein the sound insulation layer is disposed at a position separated from the ceiling.

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