Patent ID: 8676571

Claim:
An audio signal processing system, including a processor, comprising: a time-frequency conversion unit which converts an audio signal in time domain into frequency domain in frame units so as to calculate a frequency spectrum of the audio signal; a weight determination unit which sets a weighting coefficient of a subfrequency band where an amplitude of a frequency spectrum of the subfrequency band of a first frame is larger than the amplitude of the frequency spectrum of the subfrequency band of a second frame before the first frame, among subfrequency bands obtained by dividing a frequency band, larger than the weighting coefficient of the subfrequency band where the amplitude of the frequency spectrum of the subfrequency band of the first frame is not larger than the amplitude of the frequency spectrum of the subfrequency band of the second frame; a spectral change calculation unit which calculates an amount of change of the frequency spectrum of the first frame and the frequency spectrum of the second frame by totaling up a value of the weighting coefficient multiplied with an absolute value of a corresponding difference of a normalized spectrum of the first frame and the normalized spectrum of the second frame for each subfrequency band; and a judgment unit which judges the type of the noise which is included in the audio signal of the first frame in accordance with the amount of spectral change.