Infant-directed speech register in children with and without hearing loss

Abstract

Do children with hearing loss use infant-directed speech? The study examined speech characteristics of a 6-year-old child with bilateral cochlear implants and an age-matched child with normal-hearing while interacting with their infant siblings (age 29 and 20 months) and with their mothers. Child-sibling and child-mother interactions were recorded in two conditions. In the “toy” condition, the children explained to their siblings and their mothers how to assemble a toy. In the “book” condition, the children narrated a story using a picture book. Sixty-five vocalizations from each child’s speech sample were extracted in each condition. Mean fundamental frequency, fundamental frequency range, utterance duration, number of syllables per utterance, and speech rate were measured. Both children produced higher fundamental frequency, expanded fundamental frequency range, shorter utterance duration, and slower speech rate in the sibling- compared to mother-directed speech in both the “book” and “toy” conditions. For the mother-directed speech only, the children produced lower fundamental frequency, longer utterance duration and more syllables per utterance in the “book” than the “toy” condition. The results suggest that children with and without hearing loss modify prosodic characteristics of their speech when interacting with a younger sibling but the strength of the modification may be task-dependent.