| 摘要 |
<p>An automatic sound controlling apparatus includes a first adaptive filter (4) that forms a compensating signal for cancelling a stationary sound. A signal generator (7) produces a signal of predetermined shape based on a timing signal of a sound producing source (1), e.g. an automobile engine, with respect to a sound producing period of the sound producing source (1). A second adaptive filter (8) forms a compensating signal for cancelling a fluctuating sound with the signal of predetermined shape, whereby in the case that the sound producing period changes sharply, an output signal of the second adaptive filter (8) is output instead of from the first adaptive filter. <IMAGE></p> |
