Abstract

The overall goal of speech perception research is to explain how spoken language is recognized and understood. In the current research framework it is assumed that the key to achieving this overall goal is to solve the lack of invariance problem. But nearly half a century of sustained effort in a variety of theoretical perspectives has failed to solve this problem. Indeed, not only has the problem not been solved, virtually no empirical candidates for solving the problem have been produced. One explanation for this lack of progress is simply that no theory has yet hit upon the correct set of invariant properties. Another explanation is that the goal of solving the lack of invariance problem is itself misguided. The most basic claim of this dissertation is that the latter explanation is correct. ;The lack of progress in explaining speech perception exhibited by the current research framework, I argue, is not, in the first instance, due to the failure of individual theories to solve the lack of invariance problem, but rather to the common background assumption that doing so is in fact the key to explaining speech perception. ;My overall argument in support of this basic claim has three main components: criticism of the empirical results of research in the current framework; criticism of the formulation of theories generated in the current research framework; and the availability of an alternative account of phonetic structure. ;The heart of my argument is an analysis of the character of the theoretical weaknesses of three theories of speech perception: the motor theory of speech perception, the ecological theory of speech perception, and the theory of acoustic invariance. I show that, in each case, the particular theoretical problems result from trying to satisfy the common goal of identifying invariant properties of phonetic percepts. ;I analyze the methodological error embodied in the current approach to explaining speech perception as, in general, one of abstracting the wrong kinds of properties from the detail of the speech event, and, in particular, of abstracting away from dynamic and context-dependent properties