Patent attributes
A noise suppressor includes a fundamental sound source (121, 122) for generating a fundamental waveform having a predetermined frequency, and suppresses that frequency component of noise which corresponds to the predetermined frequency by generating a control sound from a signal generated by multiplying the fundamental waveform by an adaptive filter coefficient (W0, W1). The noise suppressor further includes a frequency adjusting circuit (210) for increasing or decreasing, by a predetermined amount, the frequency of the fundamental waveform output from the sound source if the phase fluctuation of the control sound detected by using the adaptive filter coefficient is larger than a predetermined threshold value. The noise suppressor has improved ability of tracking the peak frequency fluctuation of periodic noise.
