A noise suppressor includes a frequency division part dividing an input signal into bands and outputting band signals; an amplitude calculation part determining amplitude components of the band signals; a noise estimation part estimating an amplitude component of noise contained in the input signal and determining an estimated noise amplitude component for each band; a weighting factor generation part generating a different weighting factor for each band; an amplitude smoothing part determining smoothed amplitude components that are the amplitude components of the band signals temporally smoothed using the weighting factors; a suppression calculation part determining a suppression coefficient from the smoothed amplitude component and the estimated noise amplitude component for each band; a noise suppression part suppressing the band signals based on the suppression coefficients; and a frequency synthesis part synthesizing and outputting the band signals of the bands after the noise suppression output from the noise suppression part.
