The development of tone discrimination in infancy: Evidence from a cross-linguistic, multi-lab report

Abstract

We report the findings of a multi-language and multi-lab investigation of young infants’ability to discriminate lexical tones as a function of their native language, age and lan-guage experience, as well as of tone properties. Given the high prevalence of lexicaltones across human languages, understanding lexical tone acquisition is fundamen-tal for comprehensive theories of language learning. While there are some similaritiesbetween the developmental course of lexical tone perception and that of vowels andconsonants, findings for lexical tones tend to vary greatly across different laborato-ries. To reconcile these differences and to assess the developmental trajectory of nativeand non-native perception of tone contrasts, this study employed a single experimen-tal paradigm with the same two pairs of Cantonese tone contrasts (perceptually similarvs. distinct) across 13 laboratories in Asia-Pacific, Europe and North-America test-ing 5-, 10- and 17-month-old monolingual (tone, pitch-accent, non-tone) and bilingual(tone/non-tone, non-tone/non-tone) infants. Across the age range and language back-grounds, infants who were not exposed to Cantonese showed robust discrimination ofthe two non-native lexical tone contrasts. Contrary to this overall finding, the statisti-cal model assessing native discrimination by Cantonese-learning infants failed to yieldsignificant effects. These findings indicate that lexical tone sensitivity is maintainedfrom 5 to 17 months in infants acquiring tone and non-tone languages, challenging thegeneralisability of the existing theoretical accounts of perceptual narrowing in the firstmonths of life.