Testing the roles of disfluency and rate of speech in the coordination of conversation

Abstract

This thesis is concerned with two different accounts of how speakers coordinate conversation. In both accounts it is suggested that aspects of the manner in which speech is performed (its disfluency and its rate) are integral to the smooth performance of conversation. In the first strand, we address Clark's (1996) suggestion that speakers design hesitations, such as filled pauses (e.g. uh and um), repetitions and prolongations, to signal to their audience that they are experiencing difficulties during language production. Such signals allow speakers to account for their use of time, particularly when they experience disruptions during production. The account is tested against three criteria, proposed by Kraljic and Brennan (2005), for evaluating whether a feature of speech is being designed: That it be produced with regularity, that it be interpretable by listeners, and that its production varies according to the speaker's communicative intention. While existing literature offers support for the first two criteria, neither an experiment with dyads nor analyses of dialogue in the Map Task Corpus (MTC; Anderson et al., 1991) found support for the third criterion. We conclude that, rather than being signals of difficulty, hesitations are merely symptoms which listeners may exploit to aid comprehension. In the second strand, we tested Wilson and Wilson's (2005) oscillator theory of the timing of turn-taking. This suggests that entrainment between conversational partners' rates of speech allow them to make precise predictions about when each others' turns are going to end, and, subsequently, when they can begin a turn of their own. As a critical test of the theory, we predicted that speakers who were more tightly entrained would produce more seamless turn-taking. Again using the MTC, we found no evidence of a relationship between how closely entrained speakers were and how precisely they timed the beginning of their turns relative to the ends of each others' turns.