| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform proper initial training without waiting even in the case of a large background noise around a device. SOLUTION: Before training of an acoustic echo canceller 44, the background noise level coming from a slave machine is detected by a level detector 46, and the amplification gain of a variable gain amplifier 452 in a training signal generation circuit 45 is variably controlled in accordance with the detection value of this background noise level, thereby outputting a training signal sufficiently larger than the background noise level from the slave machine.</p> |
