14th International Congress of Phonetic Sciences (ICPhS-14)
San Francisco, CA, USA
Adults have difficulty discriminating non-native speech contrasts, yet young infants discriminate both native and nonnative contrasts. Language-specific influences appear by 9-10 months for consonants and phonotactic sequences, and by 6 months for vowels. Early experience is still influential in adulthood, when fluent early bilinguals still show L1 rather than L2 effects on consonant discrimination, and those exposed to a language only during their first year show enhanced sensitivity to its contrasts. Preferences for some native prosodic properties appear even earlier. Newborns prefer native over non-native connected speech, while common native syllable structures and stress patterns are preferred by 6 months. Infant babbling displays similar developmental trends, with native prosodic biases present by 6 months and segmental biases emerging by 10 months. These effects take place prior to true word production, and well before morphology and syntax. Thus, they necessarily occur at a prelexical level. It is hypothesized, then, that language-specific phonetic learning precedes acquisition of contrastive phonology, a concept of fundamental significance to understanding the nature of phonological knowledge and its function in spoken language.
Bibliographic reference. Best, Catherine T. (1999): "Development of language-specific influences on speech perception and production in pre-verbal infancy", In ICPhS-14, 1261-1264.