Children's songs to infant siblings: parallels with speech

Children aged 2;11 to 8;3 sang informally, once in the presence of their infant sibling and once when the infant was out of view. Paired excerpts from 22 children were presented to adult listeners, who were required to identify the infant-directed excerpt in each pair. Listeners' accuracy was above chance levels but below what would be expected for mothers' singing in comparable contexts. Children altered their singing style in the infant's presence by singing at a higher pitch level and with a different vocal quality.