Informational Potentials of Dynamic Speech Rate in Dialogue

We examine five spontaneous dialogues conducted in Japanese and analyze the potential of speech rate change to signal the structure of information being exchanged in dialogue. We found (1) a bi-directional correlation between speech decelerations and the openings of new information, and (2) another bi-directional correlation between speech accelerations and the absence of information openings. Our data show that the correlations hold not only in the case of a single speaker’s speech, but also in the case of multiple speakers’ sequential utterances, with or without turn shifts. We also study possible disturbances to these default correlations and identify the limitation on speakers’ cognitive resources as one major constraint that interferes with the accurate signaling of information opening by decelerated speech.