Patent ID: 6460017
Filing Date: 2002-10-01
Classification: G10L

Abstract:
A method for real-time adaption of a hidden Markov sound model, stored in a code book of a speech recognition system to a vocabulary modification in a phonetic lexicon employed in the speech recognition system comprising the steps of:making hidden Markov sound models to be recognized available in the code book according to an average value vector of their respective probability distributions; conducting a speech recognition procedure by extracting feature vectors from a speech signal and allocating the feature vectors to the probability distributions of the hidden Markov sound models from the code book; and scaling a position of the average value vector of at least one of said hidden Markov sound models to the position of the allocated feature vector via a defined adaption factor for at least one recognized sound expression of the vocabulary modification in the phonetic lexicon immediately after recognition thereof to produce an adapted average value vector, and storing the adapted average value vector in the code book as the average value vector for said at least one of said hidden Markov models.