| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a clear loudspeaking sound to listeners in respective areas with a simple configuration. <P>SOLUTION: A microphone 2 picks up voice of a talker, an amplifier 3 amplifies the voice and a speaker 4 whose directivity is controlled outputs the amplified voice. The directivity of the speaker 4 is controlled in a way that the direction of the directivity is directed along a ceiling 1 so that the voice outputted from the speaker 4 does not directly reach the listener, the acoustic reflection plates 5, 6, 7 are fitted to the ceiling so that the voice from the speaker 4 whose directivity is controlled is reflected in the acoustic reflection plates 5, 6, 7 and then the reflected voice reaches the listener. A greater amount of the reflected voice comes from an acoustic reflection plate a distance of which from the talker is greater, thereby capable of compensating distance attenuation of a direct voice from the talker. An acoustic reflection plate whose area can be revised or an acoustic plate with a reflecting face and a transmitting face or the like can properly be used. <P>COPYRIGHT: (C)2008,JPO&INPIT |
