Patent ID: 7526428
Filing Date: 2009-04-28
Classification: G10L

Abstract:
1. A method of reducing a noise component of an input speech signal comprised of signal frames on a channel comprising the steps of: (a) applying a windowed Fourier transformation to said signal frames; (b) approximating signal magnitudes of said signal frames; (c) computing Signal-to-Noise Ratio magnitudes of said signal frames; (d) detecting voice activity in said channel as a function of conditional comparisons of received Signal-to-Noise Ratios and average Signal-to-Noise Ratio thresholds; (e) detecting noise activity in said channel as a function of conditional comparisons of at least one of historical voice activity detection values, historical signal values and noise step values; (f) estimating gain in said signal frames; (g) applying an estimated noise history to said signal frames to compute a spectral gain function; (h) applying said spectral gain function to the components of said windowed Fourier transformation; and, (i) applying an inverse Fourier transform to said signal frames thereby reconstructing a noise reduced output signal frame.