ABSTRACT
In this chapter we discuss the key empirical studies in the literature on the perceptual development of phonetic categories in infancy, including consonants, vowels, and lexical tones. The results suggest that these types of phonetic categories share common underlying mechanisms. Input-driven learning and input-independent processing both exert effects and are contrast dependent. For many consonants and vowels, infants begin life as language-universal listeners, and input experience guides them to reorganize the early perceptual space, focusing them on the native-language phonological system. We report supporting evidence for this developmental pattern in our new study on Mandarin-Chinese-learning infants’ perceptual trajectory of their native tones from four to thirteen months of age.
