Fathers' unmodulated prosody in child-directed speech

Mothers and fathers modify prosodic characteristics of child-directed speech relative to adult-directed speech. Evidence suggests that mothers and fathers may differ in how they use child-directed speech as communicative partners. Thus, fathers create communicative challenges during father-child interaction that facilitate the child's adaptation to a wider potential range of interlocutors. In this paper, speech production differences are examined between mothers and fathers in child-directed speech to toddlers as compared to adult-directed speech. Using a longitudinal, large-scale design of audio recordings in naturalistic environments and automatic speech processing techniques, it was found that mothers, but not fathers, increased their fundamental frequency when addressing their toddlers. The results suggest that fathers do not modulate the prosody of their speech in the same way as mothers when communicating with their toddlers. Findings have implications for emotional and communicative practices of fathers compared to mothers and the differential role each plays in child development.