Matsushita Electric Industrial Co., Ltd.

Kuniaki Ohsawa

Tsuyoshi Kimura

Atsunao Shinoda

To provide a loudspeaker broadcasting system and a loudspeaker broadcasting apparatus which can perform a loudspeaker broadcasting of appropriate contents at each block without reducing sound clearness. Bi-directional speakerswhich performs sound-reinforcement having high intelligibility, and fire detecting sensorswhich detect fire occurrence in a tunneland send fire occurrence signals are placed in the tunnelin the tunnel extending direction. In an emergency such as a fire, emergency broadcasting is performed through each bi-directional speakerat each of the predetermined blocksin the tunnel. The emergency broadcasting is different in contents at each block, and it is alternately performed at the adjacent blocks. Further, the frequency components having a long reverberation time is removed from the loudspeaker broadcasting through the bi-directional speaker

Growing community of inventors

Kanagawa, Japan

Kuniaki Ohsawa