Evaluation of a Word Recognition System Using Syntax Analysis

A speech recognition system has been implemented which accepts reasonably natural English sentences spoken as isolated words. The major components of the system are a speaker‐dependent word recognizer, a programmed grammar, and a syntax analyzer. The system permits formulation of complete sentences from a vocabulary of 127 words. The set of sentences selected for investigation is intended for use as requests in an automated travel information system. Results are presented of evaluations for speakers using their own stored reference patterns, the reference patterns of other speakers, and composite reference patterns averaged over several speakers. For speakers using their own reference patterns the median error rate for acoustic recognition of the individual words is 11.7 percent. When syntax analysis is applied to the complete sentence, word recognition errors can be corrected and the error rate reduced to 0.4 percent.