Articulation rate in preschool children: a 3-year longitudinal study

Background: Speaking rate has implications for both clinical practice and an understanding of normal and disordered communication processes. Fundamental information on speaking rate is required by the clinician for the appropriate management of those disorders with disturbances of rate or those in which rate modification strategies are applied. One measure of speaking rate, articulation rate, excludes pause time and measures the speed with which articulators move. A developmental assessment of articulation rate is of particular interest because of its implications for changes in temporal motor aspects of speech production in development. Aims: The fundamental aim was to provide longitudinal and normative data on articulation rate in a group of preschool children. The following questions were asked. What are the articulation rates and variability in rate at ages 4, 5 and 6, and is there a developmental trend? Are speaking context, utterance length and gender significant variables? Methods & Procedures: Speech samples from four speaking contexts, spontaneous, imitated, automatic (represented by nursery rhyme narration) and repetition, were elicited from 16 normally developing children (eight boys and eight girls) at ages 4, 5 and 6. Utterances were measured in syllables per second for runs of speech without pauses within each speaking context. Outcomes & Results: In contrast to expectation, articulation rate did not increase significantly with age. Neither did variability of rate decrease with age. Results suggest that the course of development is non-linear. Automatic speech and repetition were significantly faster than imitated speech. An interaction between imitated speech and variability was found at age 4. Considerable individual differences in rate were identified. There were no gender differences and no correlations between articulation rate and utterance length. Conclusions: Unique information is provided on the development of speaking rate in preschool children together with additional normative data. The results have both theoretical and clinical implications. The data should assist the clinician in the assessment and diagnosis of rate and in rate modification management. Caution should be exercised in generalizing the results of the study in view of the small sample size and other factors.