JPS6037899A - Loudening device in tunnel - Google Patents

Abstract

PURPOSE:To attain a high intelligibility by masking the echo of a voice, which is reproduced by a loudening means, with a noise reproduced by a noise reproducing means. CONSTITUTION:The voice inputted to a microphone is amplified by a mike amplifier 6 and main amplifiers 7a-7d and is reproduced from speakers 8a-8d simultaneously. A noise generating device 9 generates a pink noise, where low- band components are emphasized, or a white noise, and fills up a tunnel with this noise by a speaker 11. Since direct and indirect sounds lower than the noise level are masked with the noise, the intelligibility is improved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is suitable for use in places with a lot of reverberation, such as tunnels and underground malls.
This relates to public address equipment.

Conventional configurations and their problems In recent years, the importance of amplification in underground passages and tunnels during disasters has been highlighted.

Regarding conventional tunnel loudspeaker equipment, Figure 1 J3 and 2
This will be explained using figures. In Figure 1, 1 is a microphone, 2 is a microphone amplifier, 38 to 3d are main amplifiers, and 4
There are speakers a to 4d.

The sound that enters the microphone 1 is amplified by the microphone amplifier 2 and main amplifiers 3a to 3d, and then sent to the speakers 4a to 4.
d and are played simultaneously. However, in such a conventional device, since the reverberation inside the tunnel is large, as can be seen from the impulse response shown in FIG.
There was a problem in that a considerable amount of extraneous echo noise could be heard, significantly reducing intelligibility.

Purpose of the Invention The present invention solves the above-mentioned drawbacks of the conventional technology, and provides good intelligibility by eliminating unnecessary echoes from other speakers even in buildings with many reverberations such as tunnels and underground malls. The purpose of this project is to provide a tunnel loudspeaker system that can be used in tunnels.

Structure of the Invention In order to achieve the above-mentioned object, the one-channel loudspeaker of the present invention is provided with a loudspeaker means for reproducing sounds, etc., and a noise reproducing means for reproducing noise sounds with emphasis on low frequencies. The structure is such that one line or indirect sound such as a reproduced voice is masked by the noise reproduced by the noise reproduction means.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below based on drawing C1. FIG. 3 is a block diagram of the tunnel loudspeaker according to the first embodiment of the present invention, in which 5 is a microphone, 6 is a microphone amplifier, 78 to 7d are main amplifiers, and 8a to 8d are
1 is a speaker for the door expansion 1, 9 is a noise generator, 10 is a main amplifier for noise reproduction, and 11 is a speaker for noise reproduction. First, the noise generator 9 generates pink noise or bowy noise with emphasized low frequency components.
1. The tunnel is filled with noise reproduction speakers 11. Next, the loudspeakers 8a to 8d reproduce J: sound and the like. Now, if you hear a sound at point A in FIG. 3, at point A you will hear the direct sound from the amplification speaker 8b and the amplification speaker 8b.

Indirect sound can be heard from 8c and 8d. However, direct sounds and indirect sounds that are lower than the level of the surrounding noise are masked by the noise and cannot be heard. Therefore A
At that point, you can hear the playback sound above the noise level. In particular, in a tunnel, there is little attenuation of bass sounds, which causes a decrease in intelligibility. However, by using noise that emphasizes the low-frequency components, it is possible to mask the bass parts, which improves intelligibility. can be raised.

Figure 4 shows the listening characteristics of impulse sound at point A. Reflected sounds that reduce clarity are masked by noise, and only the direct sound of the reproduced sound is heard. It can be seen that good intelligibility can be obtained. In FIG. 4, B indicates the noise level.

Note that it is also very effective to insert a delay circuit between the microphone amplifier 6 and the main amplifiers 78 to 7d to eliminate the influence of extra work caused by other speakers.

FIG. 5 is a block diagram of the channel widening device 1 to 1 in the second embodiment, and 12 is a mixer. The signal from the noise generator q enters the mixer 12, where the audio signal is mixed to a level higher than the noise level and reproduced by the loudspeakers 88 to 8d. According to this embodiment, the noise and voice are reproduced through the loudspeakers 8a to 8d, so the noise reproduction speaker 11 becomes unnecessary.

As described in detail, according to the present invention, unnecessary echoes and indirect sounds from speakers are masked by noise, so that good intelligibility can be achieved (1), and its industrial use value is is extremely human.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional tunnel loudspeaker system, Figure 2
3 is a block diagram of the in-tunnel loudspeaker system according to 1) in the first embodiment of the present invention. FIG. 4 is an explanatory diagram of the impulse response of the same device. 5
The figure is a block diagram of an in-tunnel public address system according to a second embodiment of the present invention. 5...Microphone, 6...Mic amplifier, 78~
7d... Main amplifier, 88-8d... Loudspeaker, 9... Noise generator, 10... Main amplifier for noise reproduction, 11... Speaker for noise reproduction, 1
2...Mixer agent Yoshihiro Morimoto Z diagram a & ga / / Figure 4 time

Claims (1)

[Scope of Claims] 1. Comprising a loudspeaker means for reproducing sounds, etc., and a noise reproducing means for reproducing noise sounds emphasizing low frequencies, the echoes and indirect sounds of the sounds etc. reproduced by the loudspeaker means are reproduced as noise. Inside the tunnel where I commanded to mask with the noise reproduced by means! Public address equipment. 2. The amplification means includes a microphone, an amplification means for amplifying the signal from the microphone, and a plurality of amplification speakers for converting the signal (No. 3) amplified by the amplification means into acoustic output. The means is configured to include a noise generating device, an amplifying means for amplifying the noise from the noise generating device, and a noise reproducing speaker for converting the noise amplified by the amplifying means into acoustic output. Tunnel loudspeaker according to scope 1. 3. The loudspeaker means has a microphone, the noise reproduction means has a noise generator, and the signal from the microphone and the noise from the noise generator are transmitted from the microphone. Equipped with a mixer that mixes so that the signal level from the noise generator is higher than the noise level from the noise generator,
2. The in-tunnel loudspeaker system according to claim 1, wherein the loudspeaker means and the noise reproduction means share an amplifying means and a speaker.