ADAPTIVE FILTERING MEANS FOR AN AUTOMATIC SOUND CONTROLLING APPARATUS

An automatic sound controlling apparatus including a first adaptive filtering means that forms a compensating signal for canceling a stationary sound, a signal producing means that produces a predetermined shape signal based on a timing signal with respect to a sound, a second adaptive filtering means that forms a compensating signal for canceling a fluctuating sound by the predetermined shape signal, whereby in the case that a sound period changes sharply, an output signal of the second adaptive filtering means is output in stead of the first adaptive filtering means.