The clear speech intelligibility benefit for text-to-speech voices: Effects of speaking style and visual guise

Abstract

This study examined how speaking style and guise influence the intelligibility of text-to-speech (TTS) and naturally produced human voices. Results showed that TTS voices were less intelligible overall. Although using a clear speech style improved intelligibility for both human and TTS voices (using “newscaster” neural TTS), the clear speech effect was stronger for TTS voices. Finally, a visual device guise decreased intelligibility, regardless of voice type. The results suggest that both speaking style and visual guise affect intelligibility of human and TTS voices. Findings are discussed in terms of theories about the role of social information in speech perception.