The intelligibility of synthesized speech in data inquiry systems.

Abstract

Recent improvements in speech technology have made synthetic speech a viable form of system feedback. However, little is known about the effects of various speech parameters on speech intelligibility and system performance. Experiment 1 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 and longer response latencies than rates of 180 wpm. In Experiment 2 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.