Utterance preparation and Stress Clash: Planning prosodic alternations

Abstract: Models of speech planning and production allow for the prosodic structure of an utterance to be only partially built when the utterance is produced. Previous studies have found evidence that higher-level prosodic units exert a stronger influence in relatively prepared speech compared to unprepared speech. A related issue is whether prosodic alternations are likewise influenced by preparation. This chapter reviews phonological and phonetic treatments of a clash-driven prosodic alternation known as the "rhythm rule", and reports on a preliminary analysis of an experimental study. The experiment tested the hypothesis that the extent to which an utterance has been prepared will affect the magnitude of prominence reduction that typically occurs in the rhythm rule. Durational decreases due to clash were observed only in prepared utterances; in unprepared speech clash unexpectedly resulted in an increase in segmental durations. These results suggest that variation due to prosodic alternations is substantially influenced by the extent to which an utterance has been prepared, and hence provide a new direction for exploration of the interaction between prosody and time-constraints on planning.