The Influence of Tonal and Atonal Bilingualism on Children’s Lexical and Non-Lexical Tone Perception

Abstract

This study examined how bilingualism in an atonal language, in addition to a tonal language, influences lexical and non-lexical tone perception and word learning during childhood. Forty children aged 5;3–7;2, bilingual either in English and Mandarin or English and another atonal language, were tested on Mandarin lexical tone discrimination, level-pitch sine-wave tone discrimination, and learning of novel words differing minimally in Mandarin lexical tone. Mandarin–English bilingual children discriminated between and learned novel words differing minimally in Mandarin lexical tone more accurately than their atonal–English bilingual peers. However, Mandarin–English and atonal–English bilingual children discriminated between level-pitch sine-wave tones with similar accuracy. Moreover, atonal–English bilingual children showed a tendency to perceive differing Mandarin lexical and level-pitch sine-wave tones as identical, whereas their Mandarin–English peers showed no such tendency. These results indicate that bilingualism in a tonal language in addition to an atonal language—but not bilingualism in two atonal languages—allows for continued sensitivity to lexical tone beyond infancy. Moreover, they suggest that although tonal–atonal bilingualism does not enhance sensitivity to differences in pitch between sine-wave tones beyond infancy any more effectively than atonal–atonal bilingualism, it protects against the development of biases to perceive differing lexical and non-lexical tones as identical. Together, the results indicate that, beyond infancy, tonal–atonal bilinguals process lexical tones using different cognitive mechanisms than atonal–atonal bilinguals, but that both groups process level-pitch non-lexical tone using the same cognitive mechanisms.