Adaptive noise suppression for digital speech signals

A method for adaptively suppressing a noise in an input signal frequency spectrum derived from overlapping input frames, the method comprising:

• computing a noisy signal power in psychoacoustic bands;
• computing a probabilistic score for a presence of a speech;
• estimating a noise power in the psychoacoustic bands based on information of past frames, the probabilistic score, and the computed noisy signal power;
• computing a gain for each frequency, based on a probabilistic heuristic, the probabilistic score and the information on the past frames;
• and
• post-processing the computed gain by performing a gain time smoothing, a gain frequency smoothing, and a gain regulation on the computed gain.

A computer program stored on a machine readable storage medium such that when executed by a processor is operable to:

• convert overlapping input frames into an input signal frequency spectrum;
• compute a noisy signal power in psychoacoustic bands;
• compute a probabilistic score for a presence of a speech;
• estimate a noise power in the psychoacoustic bands based on information of past frames, the probabilistic score, and the computed noisy signal power;
• compute a gain for each frequency, based on a probabilistic heuristic, the probabilistic score and the information on the past frames;
• and
• post-process the computed gain by performing a gain time smoothing, a gain frequency smoothing, and a gain regulation on the computed gain.