Patent ID: 6151573
Filing Date: 2000-11-21
Classification: G10L

Abstract:
An improved speech recognition system comprising:a speech recognizer; anda source normalization model coupled to said recognizer; said model derived by a method of source normalization training for HMM modeling of speech comprising the steps of:(a) providing an initial model;(b) on said initial model or following new models performing the following steps to get a new model:b.sub.1) estimation of intermediate quantities;b.sub.2) performing re-estimation to determine initial state probability, transition probability, mixture component probability and environment probability;b.sub.3) deriving mean vector and bias vector;b.sub.4) solving jointly for mean vector and bias vector using linear equations and determining variances and transformation;b.sub.5) replacing old model parameters for the calculated ones; and(c) determining after a new model is formed if it differs significantly from the previous model and if so repeating steps b.sub.1 -b.sub.5.