Prosodic categories and duration control

Abstract

Two prosodic categories are particularly interesting for examining the relationship between phonetic units and articulatory timing because they provide a clear contrast in prosodic function: The durational correlates of “sentence stress” mark constituent peaks (nuclear-accented syllables), whereas phrase-final lengthening marks constituent edges. When kinematic patterns are contrasted in nuclear-accented versus unaccented and phrase-final versus nonfinal syllables, it seems that final lengthening is a local decrease in stiffness, whereas lengthening for accent is a change in the phasing of the final (consonant) gesture relative to the opening (vowel) gesture. When interaction with overall tempo is examined, however, it is clear that the prosodic function cannot be equated directly with the dynamic parameters, since at slow tempo, phrase-final lengthening affects phasing rather than stiffness. Thus prosodic structure is not the immediate goal of the dynamic representation. Rather, there must be intermediate representations of the phonetic tasks in terms of a local tempo change (for final lengthening) and an increase in the duration of the “sonority peak” of the syllable (for sentence stress). [Work supported by the NSF.]