Infant-Directed Speech: Maternal Pitch Variability, Rate of Speech, and Child Language Outcomes

Abstract

Research regarding the influence of specific features typical of infant-directed speech (IDS) and their potential role in facilitating children’s language development is still needed. Very little evidence links features of IDS to specific or general language outcomes. Surprisingly, given their pervasive description, the potential impacts of slowed speech rate and increased pitch variability of IDS on child language outcomes have not been examined. This study asks whether decreased speech rate and increased pitch variability in IDS among 42 mother-infant dyads at 7, 10/11, 18, and 24 months predicts language outcomes at two years. Decreased maternal speech rate at seven months related to increased child expressive language outcomes at two years. Contrary to hypotheses, children who were exposed to IDS characterized by decreased pitch variability at seven months had greater expressive language outcomes at two years than children who were exposed to IDS with increased pitch variability. Possible interpretations and clinical ramifications are discussed.