Patent ID: 6122610
Filing Date: 2000-09-19
Classification: G10L

Abstract:
A method for suppressing noise in an input signal that carries a combination of noise and speech, comprising the steps of:dividing said input signal into signal blocks;applying a Discrete Fourier Transform (DFT) to the signal blocks over a number of DFT bins to provide a complex-valued frequency domain representation of each block;converting the frequency domain representations of the signal blocks to magnitude-only signals; andaveraging the magnitude-only signals across different frequency bands to provide an estimate of a short-time perceptual band spectrum of the input signal;wherein each of the different frequency bands is correlated with an associated plurality of the DFT bins;determining, at various points in time, whether said input signal is carrying noise only, or a combination of noise and speech, and, when the input signal is carrying noise only, using the corresponding estimated short-time perceptual band spectrum of the input signal to update an estimate of a long term perceptual band spectrum of the noise;determining a noise suppression frequency response based on said estimate of the long term perceptual band spectrum of the noise and the estimated short-time perceptual band spectrum of the input signal; andproviding an all-pole time-domain filter in accordance with said noise suppression frequency response for time-domain shaping of a current block of the input signal to suppress noise therein.