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 〈1-3〉 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.