| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure excellent speech quality by preventing the occurrence of howling by a reduced feedback amount, when long-distance transmission/reception of voice signals is performed between terminals connected through two-wire signal lines. <P>SOLUTION: When transmitting/receiving voice signals between first and second terminals 1, 2 connected through two-wire signal lines L1, L2, as an adjustment when canceling the feedback amount of a self-terminal signal S11, produced by an increased capacity component of the signal lines, according to the intensity thereof by a speech voice signal S10, a feedback amount adjustment circuit 111 in a feedback amount cancellation circuit 11 executes a prescribed adjustment process at the implementation of an intercom system or the configuration modification of the system. By this, the adjustment accuracy thereof is increased and a high-frequency band component of an output signal S12 after the cancellation is removed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
