Prosodic features of stances in conversation

Stance—attitudes and opinions about the topic of discussion—has been investigated textually in conversation analysis, discourse analysis, and computational models, but little attention has focused on its acoustic-phonetic properties. It is a challenge, given the complexity of stance and the many other types of meaning that share the same acoustic channels, all overlaid on the lexical and syntactic material of the message. With the goal of identifying automatically-extractable, acoustically-measurable correlates of stance-taking, this work identified signals of stance in prosodic measures of fundamental frequency, intensity, and duration in an audio corpus of dyads engaged in collaborative conversational tasks designed to elicit frequent changes in stance at varying levels of involvement. The study examined over 32,000 stressed vowels in content words spoken by 40 American English-speakers and found that f0 and intensity increased with stance strength, longer vowel duration signaled positive polarity, and a combination of measures distinguished several stance-act types, including: general agreement, weak-positive agreement, rapport-building agreement, reluctance to accept a stance, stance-softening, and backchannels. These results contribute to the understanding of the acoustic-phonetic properties of the social and attitudinal messages conveyed in natural speech.