The nature of non-native speech sound representations

Abstract

Most current theories and models of second language speech perception are grounded in the notion that learners acquire speech sound categories in their target language. In this paper, this classic idea in speech perception is revisited, given that clear evidence for formation of such categories is lacking in previous research. To understand the debate on the nature of speech sound representations in a second language, an operational definition of "category" is presented, and the issues of categorical perception and current theories of second language learning are reviewed. Following this, behavioral and neuroimaging evidence for and against acquisition of categorical representations is described. Finally, recommendations for future work are discussed. The paper concludes with a recommendation for integration of behavioral and neuroimaging work and theory in this area.

FIG. 1.

(Color online) (A) Performance on Mandarin tone learning task for non-native learners (native English listeners) and native Mandarin listeners. Error bars reflect standard error of the mean. Individual subject performance is shown in gray and group mean in black. (B) Decision strategies, assessed with decision bound models (Ashby and Maddox, 1992, 1993) for non-native learners and native Mandarin listeners from the final block in (A). Most native listeners use procedural-based strategies, whereas non-native learners use a variety of strategies, including conjunctive rules and unidimensional rules based on pitch height and pitch direction of the stimulus. A subset of non-native participants randomly guess the category identity even in the final block of learning.