METHOD AND APPARATUS FOR AUTOMATIC EVALUATION OF PRONUNCIATION

摘要

Pronunciation is automatically evaluated using techniques adapted from automatic speech recognition as shown in the figure 1. Speech, represented as a sequence of acoustic features (8), is compared to a hidden Markov model (11) of speech patterns (12) corresponding to the preselected script to obtain a probability score which is a measure of the likelihood that the hidden Markov model would have generated the sequence of observed acoustic features. In a specific embodiment, the probability score is determined by processes referred to as alignment and backtracing. Alignment is the process of calculating a maximum likelihood path established through the use of the hidden Markov model. Backtracing is the process of finding the path backwards through the network of states of the hidden Markov model and obtaining a probability score.