Matching across turns in talk-in-interaction : the role of prosody and gesture

Understanding the design of talk-in-interaction is important in many domains, including speech technology. Although phonetic, linguistic and gestural correlates have been identified for some of the social actions that conversational participants accomplish, it is only recently that researchers have begun to take account of the immediately prior interactional context as an important factor influencing the design of a speaker’s turn. The present study explores the influence of context by focussing on characteristics of short turns produced by one speaker between turns from another speaker. The hypothesis is that the speaker designs her inserted turn as a match to the prior turn when wishing to align with the previous speaker’s agenda. By contrast, non-matching would display that the speaker is non-aligning, preferring instead to initiate a new action for example. Data are taken from the AMI corpus, focussing on the spontaneous talk of first-language English participants. Using sequential analysis, such short turns are classified as either aligning or non-aligning in accordance with definitions in the Conversation Analysis literature. The degree of prosodic similarity between the inserted turn and the prior speaker’s turn is measured using novel acoustic techniques. The results show that aligning turns are significantly more similar to the immediately preceding turn, in terms of pitch contour, than non-aligning turns. In contrast to the prosodic-acoustic analysis, the results of the gestural analysis indicate that aligning and non-aligning are differentiated by the use of distinct gestures, rather than by the matching (or non-matching) of gestures across the adjacent turns. These results support the view that choice of pitch contour is managed locally, rather than by reference to an intonational lexicon. However, this is not the case for speakers’ use of gesture. The implications of these findings for a model of talk-in-interaction are considered, along with potential applications.