To perform evacuation guidance with high clarity without mixing guidance advice sounds by the speakers of sections adjacent to each other by selectively loud-speaking an evacuation guidance sound signal from a directional speaker.
When an accident (abnormality) takes place in a tunnel, an abnormality detector 1b outputs an abnormal detection signal. A directivity switching device 3a of a section which is located on the side closer to an A evacuation opening than an abnormality occurrence position detects that the detector 1b is located closed to a B evacuation opening than the section, switches the directivity direction of a directional speaker 2a into the opposite direction of the A evacuation opening and outputs an evacuation guidance sound signal 41 guiding to the A evacuation opening to the speaker 2a. Meanwhile, a directivity switching device 3b of a section which is located on the side closer to the B evacuation opening than the abnormality occurrence position switches the directivity direction of a directional speaker 2b into the opposite direction of the B evacuation opening and outputs an evacuation guidance sound signal 43 guiding to the B evacuation opening to the speaker 2b.
HASHIMOTO HIROYUKI
KAKUBARI ISAO
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