Explicit Pronunciation Training Using Automatic Speech Recognition Technology

A system is described, provisionally named Pronto, which uses automatic speech recognition (ASR) for training pronunciation of second languages in adult learners. The first version of Pronto was developed for native speakers of American English learning Spanish and for Mandarin Chinese speakers learning English. Pronto grows out of work in the Indiana Speech Training Aid (ISTRA) research program, which has demonstrated significant improvement in the pronunciation of hearing-impaired and normal-hearing but misarticulating children through the use of ASR-derived feedback. This feedback has also been shown to improve pronunciation in adult learners of a second language. Methods are described for developing training in Pronto, and results are presented from evaluating classes of speech recognizers for use in different aspects of pronunciation training.