ABSTRACT

It has been well documented that infants are able to discriminate among the phonetic units of a range of languages; however, a significant decline in this ability occurs between 6-8 and 10-12 months of age (e.g., Werker and Tees, 1984). During this period of first language (L1) perceptual attunement, perception of native-language consonants improves, beginning the process of a neural commitment to those auditory patterns (Rivera-Gaxiola et al., 2005). These simultaneous processes of decline in non-native sound discrimination and facilitation of native sound perception have been attributed to the learning of the acoustic and statistical regularities of speech, which serve as the foundation for acquiring more complex patterns as the lexicon develops (Kuhl et al., 2006). This process for the child, the epitome of the “early” language learner, raises the question of the impact of age on second-language (L2) speech perception, and underscores the important role of continued neural plasticity in L2 perceptual category development.