METHOD AND APPARATUS OF HIERARCHICALLY ORGANIZING AN ACOUSTIC MODEL FOR SPEECH RECOGNITION AND ADAPTATION OF THE MODEL TO UNSEEN DOMAINS

摘要

A method of organizing an acoustic model for speech recognition is comprised of the steps of calculating a measure of acoustic dissimilarity of subphonetic units. A clustering technique is recursively applied to the subphonetic units based on the calculated measure of acoustic dissimilarity to automatically generate a hierarchically arranged model. Each application of the clustering technique produces another level of the hierarchy with the levels progressing from the least specific to the most specific. A technique for adapting the structure and size of a trained acoustic model to an unseen domain using only a small amount of adaptation data is also disclosed.