Speech recognition for Japanese spoken language

Abstract

This paper overviews the speech recognition issues for the Japanese language, and introduces three a n t research projects conducted at NTT (Nippon Telegraph and Telephone) Human Interface Laboratories and ATR Interpreting Telephony Research Laboratories. The fist topic is stochastic language models for sequences of Japanese characters to be used in a Japanese dictation system with unlimited vocabulary. The second topic is an accurate and efficient algorithm for verylarge-vocabulary continuous speech recognition based on an HMM-LR algorithm. This algorithm was applied to a telephone directory assistance system that recognizes spontaneous speech having the vocabulary size of roughly 80, OOO. The third topic is a continuous speech recognition system based on strategies of the phoneme-context-dependent (allophonic) modeling and parsing.