METHODS AND APPARATUS FOR DISCRIMINATIVE TRAINING AND ADAPTATION OF PRONUNCIATION NETWORKS

A speech recognition method comprises the steps of using given speech data and the N-best algorithm to generate alternative pronunciations and then merging the obtained pronunciations into a pronunciation networks structure; using additional parameters to characterize a pronunciation network for a particular word; optimizing the parameters of the pronunciation networks using a minimum classification error criterion that maximizes a discrimination between different pronunciation networks; and adapting parameters of the pronunciation networks by, first, adjusting probabilities of the possible pronunciations that may be generated by the pronunciation network for a word claimed to be a true one and, second, to correct weights for all of the pronunciation networks by using the adjusted probabilities.