Thai Spelling Recognition Using a Continuous Speech Corpus
Abstract
Spelling recognition provides alternative input method for computer systems as well as enhances a speech recognizer to cope with incorrectly recognized words and out-of-vocabulary words. This paper presents a general framework of Thai speech recognition enhanced with spelling recognition. Towards the implementation of Thai spelling recognition, Thai alphabets and their spelling methods are analyzed. A method based on hidden Markov models is proposed for constructing a Thai spelling recognition system from an existing continuous speech corpus. To compensate speed difference between spelling utterances and continuous speech utterances, the adjustment of utterance speed is taken into account. Two alternative language models, bigram and trigram, are used to investigate the performance of spelling recognition under three different environments: close-type, open-type and mix-type language models. Using the 1.25-times-stretched training utterances under the mix-type language model, the system achieves 87.37% correctness and 87.18% accuracy for bigram, and up to 91.12% correctness and 90.80% accuracy for trigram.
Paper presented at the Int. Conf. on Intelligence in Communication Systems (IntellComm 2004), Bangkok, Thailand, 23–26 Nov 2004.