Predicting One’s Turn With Both Body and Mind: Anticipatory Speech Postures During Dyadic Conversation

Abstract

In natural conversation, turns are handed off quickly, with the mean downtime commonly ranging from 7 to 423 ms. To achieve this, speakers plan their upcoming speech as their partner’s turn unfolds, holding the audible utterance in abeyance until socially appropriate. The role played by prediction is debated, with some researchers claiming that speakers predict upcoming speech opportunities, and others claiming that speakers wait for detection of turn-final cues. The dynamics of articulatory triggering may speak to this debate. 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 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 next opportunity 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), prior to audible speech. This effect was moderated by the number of words in the upcoming utterance; postures arose up to 3,000 ms before acoustic onset for short utterances of 1–3 words. We discuss the implications for models of conversation and phonetic control.

Ultrasound measurements of interactive turn-taking in question-answer sequences: Articulatory preparation is delayed but not tied to the response

“…Comparing the present results to those from [ 35 ], on articulatory preparation (in the form of lip openings) in spontaneous conversation, one can say that the overall conclusions of the two studies appear compatible with each other. In a video corpus of spontaneous conversation, these authors compared how far participants opened their lips in advance of turns starting with sounds that required large versus small lip openings.…”

“…Although the used measure was quite different from that used in the present study, both opening the lips and moving the tongue are actions that are likely to be performed in order to prepare for articulation of certain speech sounds or phonemes. The study [ 35 ] found that articulatory preparation could start several seconds before a response, especially for short responses. These effects even were present even longer before the response than in the present study, as early as three seconds before (compared to up to two seconds in the present study).…”

“…However, one should keep in mind that the turns investigated in that study were very different from the ones in the present study. The present study looked at answers to open quiz questions only, which presumably require quite some amount of planning time (including retrieval of the response from memory), whereas the study by Krause and Kawamoto [ 35 ] considered all turns in a spontaneous corpus. The latter would include a large variety of turns, such as backchannels and continuations after backchannels.…”

“…This may imply that inbreaths are regarded as part of the turn itself and are generally drawn just before the turn, instead of longer in advance such that the upcoming speaker is prepared for articulation earlier. The second study that investigated the timing of articulatory preparation [ 35 ] looked at preparatory lip movements as captured with video recordings in a conversational corpus. They investigated how widely speakers opened their mouths in advance of a turn starting with a sound that requires a large versus a small mouth opening.…”

“…However, one has to keep in mind that this study included all turns in the corpus, also backchannels and presumably turns that were a continuation of previously initiated turns, and not necessarily a response to the previous turn (see [ 10 ]). These two existing studies on the timing of articulatory preparation thus show conflicting results, that is, inbreaths appear to occur just before the start of the turn [ 33 ], whereas preparatory mouth movements can occur much longer in advance [ 35 ]. However, note that these are both observational studies that did not investigate in what way articulatory preparation was related to the moment that interlocutors could start planning their turn.…”