Context, Repetition and Synthesized Speech Intelligibility

Abstract

Two studies were conducted to explore the effects of various parameters on rule-based synthetic speech intelligibility. Experiment I examined the effect of situational context clues and speech rate on synthesized speech intelligibility. Subjects who received pragmatic context information prior to each message had transcription error rates 50% lower than those who received no context information. Speech rates of 250 words per minute (wpm) yielded significantly more transcription errors than rates of 180 wpm. In Experiment II, the effects of speech rate, message repetition, and location of information in a message were examined. Transcription accuracy was best for messages spoken at 150 or 180 wpm and for messages repeated either twice or three times. Words at the end of messages were transcribed more accurately than words at the beginning of messages. Subjective ratings indicated that subjects were aware of errors when incorrectly transcribing a message even though no feedback was provided.