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

Area of Science:

• Linguistics
• Psychology
• Speech Science

Background:

• Conversational turn-taking involves rapid speech handoffs with minimal downtime.
• Speakers plan upcoming utterances during a partner's turn, but the precise timing and predictive mechanisms are debated.
• Existing models often assume utterances are initiated all at once, challenging phonetic coordination principles.

Purpose of the Study:

• To investigate whether anticipatory articulatory postures occur during natural conversation.
• To examine the timing and conditions under which these postures emerge before audible speech.
• To provide evidence for or against predictive planning in conversational speech production.

Main Methods:

• Analysis of a pre-existing audiovisual database of dyads in unstructured conversation.
• Utilized video motion tracking to measure speakers' lip areas over time.
• Correlated lip area changes with acoustic onset of utterances, specifically focusing on phonetic features and utterance length.

Main Results:

• Speakers exhibited smaller lip areas before audible speech when upcoming syllables involved labial consonants or rounded vowels.
• These anticipatory lip postures were observed up to 3,000 ms before acoustic onset for short utterances (1-3 words).
• The findings suggest a predictive component in conversational speech planning and articulatory control.

Conclusions:

• Conversational speakers engage in anticipatory articulatory planning, adjusting postures before initiating speech.
• This challenges the notion of delayed initiation and supports predictive models of speech production.
• Findings have implications for understanding the dynamics of natural conversation and phonetic coordination.