Predicting One’s Turn with Both Body and Mind: Anticipatory Speech Postures during Dyadic Conversation
Date: February 12, 2021
Location: PC Zoom Room
Speakers: Peter Krause (CSU Channel Islands)
In natural conversation, turns are handed off quickly, with the modal downtime commonly reported as 200 milliseconds. To achieve this, speakers predict both the content of their partners’ unfolding turns and when those turns will end. In parallel, speakers plan their own upcoming speech, holding the audible utterance in abeyance until it is time to take the floor. Little research in this area has examined the specifics of articulatory triggering. It is often assumed that the prepared utterance is held in a response buffer and then initiated all at once. This assumption is consistent with standard phonetic models in which articulatory actions must follow tightly prescribed patterns of coordination. This assumption has recently been challenged by several single-word production experiments in which participants partly positioned their articulators to anticipate upcoming utterances, long before starting the acoustic response. The present study considered whether similar anticipatory postures arise when speakers in conversation await their turn to speak. We analyzed a pre-existing audiovisual database of dyads engaging in unstructured conversation. Video motion tracking was used to determine speakers’ lip areas over time. When utterance-initial syllables began with labial consonants or included rounded vowels, speakers produced distinctly smaller lip areas (compared to other utterances), up to 1000 milliseconds before the start of audible speech. The specific durations of anticipatory postures varied and were partly predictable from the length of the partner’s preceding turn. This result carries implications both for models of turn taking and for models of phonetic planning and control.