Diachronic Explanations of Sound Patterns

Phonological systems show clear signs of being shaped by phonetics. Sound patterns are overwhelmingly phonetically 'natural', in that they reflect the influence of physical constraints on speech production and perception, and categorical phonological processes often mirror low-level gradient phonetic effects. The question of how best to explain and model the influence of phonetics on phonology has been approached in different ways, one of which situates the locus of explanation in the diachronic domain of language change, in particular sound change. On this view, recurrent sound patterns merely reflect recurrent sound changes with phonetic origins, typically in speech perception. Explicit models of sound change are reviewed and illustrated, in particular Ohala's listener-based model and Blevins' Evolutionary Phonology framework, and the relevance of exemplar-based models of speech production and perception is also noted. Current issues of controversy regarding the adequacy of diachronic vs. synchronic explanations for the typology of sound patterns are surveyed.