Age-dependent intonational changes in child-directed speech

Abstract

The linguistic properties of child-directed speech (CDS) change over time as children get older and their language skills develop. The focus of this research is on prosodic changes of CDS within the earliest years of children’s life, especially on the changes in melody. We analyzed mothers’ speech from Providence corpus, a collection of longitudinal (bi-monthly) recordings of mother-child spontaneous speech interactions from six English-speaking children between 1.0–3.5 years of age (363 h of audio). Raw prosodic features were extracted from speech using OpenSMILE toolkit. Timing of prosodic events with respect to segmental content was estimated with automatic alignment of orthographic transcripts and the speech signals. Analyses of prosodic features in the data show that mothers’ voice in CDS changes during the second and the third years of their children life, as the mean fundamental frequency lowers significantly, while the within-utterance fundamental frequency variability doesn’t change.