Disentrainment may be a Positive Thing: A Novel Measure of Unsigned Acoustic-Prosodic Synchrony, and its Relation to Speaker Engagement

Synchrony is a form of entrainment which consists in a relative coordination between two speakers, who throughout conversation simultaneously vary some properties of their speech. We describe two novel measures of acoustic-prosodic synchrony that are derived from a time-series analysis of the speech signal. Both of these measures reward positive synchrony (entrainment) and, while one penalizes negative synchrony (disentrainment), the other one rewards it. We describe significant correlations between the second measure and a number of positive social characteristics of the conversations, such as degree of speaker engagement, in a corpus of task-oriented dialogues in Standard American English. Since these correlations are not found to be significant for the first measure, our results suggest that disentrainment may sometimes have a positive effect on the development of conversation.