Does the intensification of what can be called "language-specific speech perception" around reading onset occur as a function of maturation or experience? Preschool 5-year-olds with no school experience, 5-year-olds with 6 months' schooling, 6-year-olds with 6 months' schooling, and 6-year-olds with 18 months' schooling were tested on native and nonnative speech contrasts, phonological awareness, and letter identification. Native speech perception was predicted by phonological awareness, but not school experience or age, whereas nonnative speech perception was negatively related to school experience and had no relationship with age or phonological awareness. Over and above any limitation of a possible selection bias associated with parents' choice of school entry age, the results suggest that intensified language-specific speech perception is due to more robust phoneme categories: increased phonological awareness facilitates judgments of native phoneme membership, whereas increased experience with phoneme-to-grapheme mapping assists in the process of disregarding allophonic variations within native phoneme classes. (Contains 2 tables and 3 figures.)