In this paper I shall present a theory of phonetic interpretation of headed phonological representations. The phonological representations in question are non-segmental, hierarchical, graphical objects similar to those in common use in autosegmental, metrical, dependency and ‘government and charm’ phonology, although the details of the phonological formalism I employ are different in some respects from each of these. The theory of phonetic interpretation is based on a parametric, dynamic model of phonetic representation. The distinction between ‘head’ and ‘non-head’ constituents is central to the phonetic interpretation model. As well as being formally explicit, I have developed a computational implementation of this theory, constituting a novel speech synthesis program, ‘YorkTalk’. Consequently, although the theory, like any other, is likely to contain certain faults, it goes beyond pencil-and-paper phonological theories, in that it is capable of algorithmically generating quite natural-sounding speech-like signals of a superior quality to other methods of generating synthetic speech, albeit only for isolated words.

Through construction of predictive models, phoneticians are making increasingly sophisticated attempts to account for certain aspects of the phonological structure of languages from very general principles(Stevens 1989; Lindblom 1984; Ohala 1990, 1992).

In this paper, I examine sonority and place of articulation constraints on the syllabification of consonants in clusters. I argue that (i) both sonority and place of articulation relationships are important in determining the syllabification of consonants in clusters, (ii) well-formed sonority and place relationships are detectable both through phonotactics and through repair strategies that apply if the constraints on sonority and place are not met, (iii) sonority and place constraints are both structurally determined and (iv) place of articulation does not form part of the sonority relationship between consonants as the structural conditions for the licensing of sonority and for the licensing of place of articulation may differ (see Clements 1990a: 313). However, place of articulation restrictions, while independent of sonority restrictions, are, like sonority restrictions, structurally defined.

In order to adequately describe the application of phonological rules across word boundaries, phonologists have appealed to the notion of prosodic domains (Selkirk 1980, 1986; Nespor & Vogel 1982, 1986; Kaisse 1985; Inkelas & Zee 1990). This research has suggested that the domains within and across which rules apply cannot be defined in purely syntactic terms, but rather that a domain structure consisting of prosodic entities such as the phonological word, phonological phrase and intonational phrase must be built up from the syntactic structure. It is to these prosodic categories that phonological rules refer. Prosodic domains are derived from but not necessarily coextensive with syntactic or morphological domains. In fact, some of the best evidence for the necessity of a prosodic structure in addition to a syntactic structure comes from cases where the two do not match, and where the correct phonological generalisations can only be captured in terms of the prosodic structure. Igbo presents just such a mismatch. This paper will examine two rules - ATR vowel harmony and vowel assimilation - that make the mismatch clear. These two rules apply in complementary situations: harmony applies only within the word, assimilation only between words. Both rules delineate the same domain, although one operates within the domain boundaries, one across them.