Analysis of phoneme and pause durations in conversational and clear speech

Abstract

When speech is spoken “clearly” the durations of segments and words increase relative to “conversational” speech, and there is a corresponding drop in average speaking rate. [Picheny, Durlach, and Braida, J. Acoust. Soc. Am. Suppl. 1 67, S38(1980)]. We report new measurements of pause durations (silence gaps exceeding 10 ms between words) and phoneme durations for content words in 50 nonsense sentences as a function of speaking mode. Separate statistical analyses were made for conversational durations, clear durations, and the percentage increase of durations. Results show that the percentage increase is strongly phoneme dependent: It varies from 15% for voiced plosives to 95% for semivowels. Analysis with respect to factors such as stress, serial position, and environment suggests that different production rules are used in the two speaking modes. [Work supported by NIH.]