Characterising Turn-Taking and Interlocutors’ Synchrony in Naturalistic Conversation: Effect of Interpersonal Rhythmic Coordination

Effective conversation involves rhythmic coordination and synchrony between interlocutors. This thesis investigated these dynamics in 15 Swiss-German speaking dyads during two phases of naturalistic conversations before and after a structured rhythmic coordination task as a conditional manipulation. We extracted rhythmic- prosodic features (speech rate, fundamental frequency, intensity) and turn-taking events (gaps, overlaps, pauses, backchannels), and introduced a novel deviation- based, time-resolved measure of turn-level synchrony via generalised additive mixed models alongside probabilistic Markov models for turn-taking event transitions. Results revealed that while the chronometry of turn-taking sustained across conditions and the structure of turn-taking didn’t shift significantly post-entrainment, dyads still presented an enhancement in turn-taking construction, indicating more confidence was built up. Secondly, while fundamental frequency and intensity as individual factors showed weak alignment, speech rate emerged as the primary factor of synchrony, displaying significantly stronger convergence following rhythmic coordination tasks over time. Lastly, the frequency of backchannels was identified as the strongest predictor of dyadic synchrony considering all three acoustic dimensions together, suggesting these interactive signals function as active phase-locking mechanisms rather than passive feedback. These findings demonstrate that while the clock of conversation and the flow of turn-taking are relatively fixed, the synchrony of verbal interaction can be seen as a plastic, dynamic state driven by predictive rhythm and active listener engagement.