| 摘要 |
PROBLEM TO BE SOLVED: To automatically control a filter coefficient to a proper value. SOLUTION: In this audio tone canceller, an adaptive signal processing section 14 uses an audio signal for a reference signal and a signal outputted from a microphone 13 for an object signal so as to conduct adaptive signal processing to minimize power of an error signal (e) thereby updating a coefficient of an adaptive filter. A gain setting section 18 monitors the coefficient of the adaptive filter and controls the gain of a variable gain amplifier 16 provided between an audio source and an adaptive signal processing section so that the filter coefficient reaches the set value or enters the set range. |
