Exemplar dynamics: Word frequency, lenition and contrast

Abstract

Exemplar theory was first developed as amodel of similarity and classification in perception. In this paper, the theory is extended to model speech production as well as speech perception. Straightforward extension of the model provides a formal framework for thinking about the quantitative predictions of usage-based phonology, as proposed by Bybee. A model is proposed which allows us to derive the finding that leniting historical changes are more advanced in frequent words than in rarer ones. Calculations using this model are presented which reveal the interaction of production noise, lenition and entrenchment. A realistic treatment is also provided for the time course of a phonological merger which originates from lenition of a marked category.