Iwatsu Electric Company Ltd.

Tohru Abe

Naoyuki Yamaguchi

An audio teleconferencing apparatus which permits two-way communications between more than two parties without the necessity of complete switching and does not allow a loss to increase in a communication channel of a particular speaker. The audio teleconferencing apparatus further comprises more than two line interface circuits, each provided with a voice activity detector for detecting voice activity in a received speech signal, a received-speech variable loss for inserting a loss into a speech receiving path when the received speech signal is voice non-active, and a sending-speech variable loss for inserting a loss in a speech signal transmission or sending path when the speech to be sent is voice-active, whereby a certain loss is inserted in any four-wire multiplex loop in the line interface circuit.

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Hino, Japan

Tohru Abe