Patent ID: 8306817
Filing Date: 2012-11-06
Classification: G10L

Abstract:
1. A feature extraction system in a speech recognition system, comprising: a time-to-frequency transform component configured to receive a time domain frame of a speech signal and transform the frame into a frequency domain; a frequency filter component configured to filter frequency components of the transformed frame and to provide an n-dimensional vector of n coefficients indicative of power in n unfiltered frequency bands of the transformed frame, one of the coefficients indicating the power in each unfiltered frequency band; a processor that is a component of a computing device that utilizes a gain estimation component to estimate a gain for each individual dimension of the n-dimensional vector and to adjust the coefficient for each of the n dimensions based on the gain estimated for each of the n dimensions to obtain n adjusted coefficients; a derivative generation component configured to utilize a linear regression formula to generate first and second derivatives of the n adjusted coefficients over a sequence of frames; and an output component configured to output a feature vector including the n adjusted coefficients, the first derivatives, and the second derivatives for use by a decoder in the speech recognition system.