A continuous speaker-independent putonghua dictation system

We describe new methods for continuous putonghua speech recognition. We have augmented the IBM HMM-based continuous speech recognition system with the following features. First, we treat tones in putonghua as attributes of certain phonemes, instead of syllables. We call those phonemes with tone tonemes. Second, instantaneous pitch is treated as a variable in the acoustic feature vector, in the same way as cepstra or energy. Third, by designing a set of word-segmentation rules to convert the continuous Chinese text into segmented text, the trigram language model works effectively. By applying those new methods, a speaker-independent, very-large-vocabulary continuous putonghua dictation system can be constructed.