| 摘要 |
PROBLEM TO BE SOLVED: To suppress decrease in the learning precision of an echo path, even when a noise component of the input signal of an echo canceller is large without making a threshold large by controlling the learning of the echo canceled and its stop, when reference input signal power is larger than a prescribed value, when a receive signal contains a sound and is less than the threshold, and when the receive signal contains no sound. SOLUTION: After various flags, data, etc., stored in a RAM are initialized, a control part 32 decides the level of the reference input signal power and a sound detector 31 decides whether or not the receive signal contains sound. Furthermore, the control part 32 decides whether or not learning can be performed, according to the decision result of the referenced input reference power and the sound/silence decision result of the receive signal. When it is decided that the learning can be performed, a line-side echo canceller 30 learns an echo path, when it is decided that it is disable state, the line-side echo canceller 30 stops the learning of the echo path. |
