The Perception of Synthetic Speech in Noise

Abstract

Although much information about synthetic speech has been acquired over past decades, we have been unable to find in the literature a systematic examination of the perception of synthetic speech in noise. Simpson [1] has reported that synthetic speech altitude callouts to airline pilots in widebody jet cockpit noise at a S/N of -10 dB for the first time were 99.1% intelligible and that synthetic speech voice warnings to helicopter pilots in simulated helicopter noise at a S/N ratio of -22 dB were 99.2% intelligible [2]. Nusbaum [3] has reported that perceptual confusions for synthetic CV and VC syllables were quite different than confusions observed for natural speech degraded by noise. Pisoni (personal communication) indicates that one of two synthetic speech systems with very high levels of segmental intelligibility in quiet, showed greater decrements in the intelligibility of CV syllables in noise than did the other system. Clark [4] reported little difference in the intelligibility of vowels in noise for synthetic and natural speech, whereas natural CV syllables were clearly superior to synthetic CV syllables under all noise conditions.