Developmental patterns of speech production in children

It has been suggested that pauses between words could act as indices of processes such as selection, retrieval or planning that are required before an utterance is articulated. For normal meaningful phrase utterances, there is hardly any information regarding the relationship between articulation and pause duration and their subsequent relation to the final phrase duration. Such associations could provide insights into the mechanisms underlying the planning and execution of a vocal utterance. To execute a fluent vocal utterance, children might adopt different strategies in development. We investigate this hypothesis by examining the roles of articulation time and pause duration in meaningful phrase utterances in 46 children between the ages of 4 and 8 years, learning English as a second language. Our results indicate a significant reduction in phrase, word and interword pause duration with increasing age. A comparison of pause, word and phrase duration for individual subjects belonging to different age groups indicates a changing relationship between pause and word duration for the production of fluent speech. For the youngest children, a strong correlation between pause and word duration indicates local planning at word level for speech production and thus greater dependence of pause on immediate word utterance. In contrast for the oldest children we find a significant drop in correlation between word and pause indicating the emergence of articulation and pause planning as two independent processes directed at producing a fluent utterance. Strong correlations between other temporal parameters indicate a more holistic approach being adopted by the older children for language production.