Global and detailed speech representations in early language acquisition

Abstract

We review data and hypotheses dealing with the mental representations for perceived and produced speech that infants build and use over the course of learning a language. In the early stages of speech perception and vocal production, before the emergence of a receptive or a productive lexicon, the dominant picture emerging from the literature suggests rather non-analytic representations based on units of the size of the syllable: Young children seem to parse speech into syllable-sized units in spite of their ability to detect sound equivalence based on shared phonetic features. Once a productive lexicon has emerged, word form representations are initially rather underspecified phonetically but gradually become more specified with lexical growth, up to the phoneme level. The situation is different for the receptive lexicon, in which phonetic specification for consonants and vowels seem to follow different developmental paths. Consonants in stressed syllables are somewhat well specified already at the first signs of a receptive lexicon, and become even better specified with lexical growth. Vowels seem to follow a different developmental path, with increasing flexibility throughout lexical development. Thus, children come to exhibit a consonant vowel asymmetry in lexical representations, which is clear in adult representations