Abstract
The phenomenon of acoustic-phonetic variability in the way words, syllables and sound segments are produced in different contexts in fluent continuous speech is well known, and raises the question of whether this variability is governed by abstract structures at higher levels. Evidence in support of this possibility is Dound both in phonetic rules based on native language user intuitions, and in measurements of phenomena that are less accessible to intuition, such as preboundary lengthening. Early investigations focussed on traditional morphosyntactic structures, such as lexical words and syntactic clauses and phrases, as candidates for the abstract structures that might govern phonetic variability. In recent decades, however, developments in the theory of prosody have provided a new set of candidate structures in the form of the elements of the prosodic hierarchy. These include constituent structures such as utterances, intonational phrases, prosodic words etc., as well as prominences such as nuclear and prenuclear pitch accents. Evidence is accumulating that many aspects of phonological and phonetic variation in spoken utterances are systematic with respect to these prosodic structures. In this talk we will explore the hypothesis that traditional morphosyntactic structures influence the phonetic realization of words and sounds indirectly, via their influence on the prosodic structures that directly govern the phonetic choices that speakers make.