Articulation rate and speech rhythm in child-directed speech and adult-directed speech

Abstract

Introduction: Studies have demonstrated that mothers exaggerate linguistic, segmental and supra-segmental properties of Child-Directed Speech. However, these studies have majorly focused on acoustic characteristics of pitch and its related measures. There has been relatively little research on speech rhythm. Though many studies report slower articulation rate relative to Adult-Directed Speech, still there is no conclusive evidence across different languages. Aims: This study aims to examine articulation rate and rhythm in Kannada speaking mothers, a Dravidian language which is less explored. Methods and Material: Twenty-five dyads of mothers and their children were recruited from the local community through random sampling for the study. The mean age of these children was 2.08 years (SD = 0.61, range= 1.89). The mean age of mothers was 30.96 years (SD= 3.44, range= 13). Articulation rate was calculated by dividing the number of syllables per second by the total duration of fluent speech in each two-minute sample. Speech rhythm was measured using an automatized approach, i.e., Envelope Modulation Spectra (EMS). Results: Results demonstrated that mothers spoke slower to their children when compared to speaking with the adult supporting the universality nature of Child-Directed Speech. Conclusions: However, results showed no conclusive evidence for the analysis of speech rhythm and hence gives a future direction to explore on the use of EMS in the normal population is mandated.