Explaining boundary perception in spontaneous French conversation: Acoustic and phrasal metrics.

Abstract

Prosodic structure in speech derives from both linguistic structure, particularly syntax, and performance factors such as speech rate. The combination of influences means that predicting the structure of a spontaneous utterance remains a major challenge. One approach has been to survey listeners and take their perceptions as the basis for analysis [e.g., Cole et al., Lab.Phonol. (2010)]. A study of this type in French compared perceptions of two types of spontaneous speech: informal conversation and more formal journalistic discussion. 25 naive native speakers of French listened to recordings of both types and indicated where they perceived boundaries between groups of words. Their responses were then compared to acoustic measurements and analyzes of the phrasal structure of the conversations. The presence of a pause and a rise in F0 were the most reliable acoustic correlates of a perceived boundary. Preliminary analyzes of phonological phrase structure suggest that the thresholded boundary weight hypothesis of Breen et al. [2010 Lang. Cog. Proc.] is a promising metric for explaining the pattern of boundary perception in these data. Locations were more often perceived as boundaries when the sum of the sizes of just‐completed and upcoming constituents (measured in numbers of phonological phrases) is larger.