Speaker adaptation in large-vocabulary voice recognition

A speaker-trained voice recognition system with a large vocabulary has a serious weak point, that is, the user must register a large number of words prior to its use. To be freed from this problem, the authors have studied a speaker adaptation method. This method follows two steps -- 1) selection of "persons" who have voices similar to the user\´s and 2) generation of a speaker-adapted dictionary from their dictionaries. Results of simulation using 1000-word speech samples by 40 male speakers (20 for standard dictionaries and 20 for performance evaluation) are reported. The results indicated the advantage of this method. The speaker-trained dictionary gave 90.1% recognition accuracy, the speaker-independent dictionary gave 83.6%, and the speaker-adapted dictionary which required only 10% of the vocabulary for training gave 85.7%.