Prosodic planning: Effects of phrasal length and complexity on pause duration

Research on pause duration has mainly focused on the impact of syntactic structure on the duration of pauses within an utterance and on the impact of syntax, discourse, and prosodic structure on the likelihood of pause occurrence. Relatively little is known about what factors play a role in determining the duration of pauses between utterances or phrases. Two experiments examining the effect of prosodic structure and phrase length on pause duration are reported. Subjects read sentences varying along the following parameters: a) the length in syllables of the intonational phrase preceding and following the pause, and b) the prosodic structure of the intonational phrase preceding and following the pause, specifically whether or not the intonational phrase branches into smaller phrases. In order to minimize variability due to speech rate and individual differences, speakers read sentences synchronously in dyads. The results showed a significant post-boundary effect of prosodic branching and significant pre- and post-boundary phrase length effects. The results are discussed in terms of production units.