What Do Child-directed Lexical Tones Tell Us About The Nature Of Child-directed Speech?

Abstract

Child-directed speech has been found to facilitate children’s speech and language development. However, how the acoustic modifications in child-directed speech promote speech and language learning in children is unclear. One hypothesis is that in child-directed speech, adults exaggerate the phonemic contrasts to make them more salient for children to acquire. Another hypothesis is that adults express affective emotions in child-directed speech to promote child-adult interactions and facilitate speech and language learning. In Chinese, pitch is used both for making phonemic contrasts (lexical tones) and expressing emotions (prosody). To understand factors contributing to children’s speech acquisition, we examined the use of pitch in child-directed Mandarin and Cantonese lexical tones to test the two hypotheses of child-directed speech.