Adults' and infants' perception of infant-directed speech and song

Infant-directed speech, also sometimes described as “musilanguage”, has acoustic characteristics overlapping with those of infant-directed singing. In the present contribution we determine whether native-English-speaking adults and infants from native-English speaking households discriminate between infant-directed speech and song in a nonnative language and which acoustic features are typical of their speech or song perception. Twentyfour native English-speaking adults rated Russian speech and song samples taken from naturalistic infant-directed recordings. Furthermore, 32 infants (6 to 9 months) were tested in a head-turn preference procedure on a selection of the stimuli rated by adults. Results showed that both infant and adults discriminated between infant-directed speech and singing in a foreign language. In adults, tempo and pitch variability accounted for perceived differences. Moreover, infants, independently of age, attended longer to song than to speech – an intriguing result underlining the importance of studying infantdirected singing and its role for early linguistic development.