Investigating speech processing skills in young children

Abstract

ABSTRACT This paper stresses the need to refer to normal control data when assessing children with speech disorders. It is based on the findings of a completed, one‐year, full‐time research project designed to investigate the normal development of speech, auditory and rhyme skills within a psycholinguistic framework (Stackhouse & Wells, 1993). The aim of the project was to examine phonological processing skills in normally developing children for comparison with children presenting with speech, lexical and literacy disorders. A range of tasks was presented to 100 normally developing children, aged 3–7 years. The tasks included auditory discrimination, rhyme judgement, detection and production; speech repetition, naming and continuous speech. The tasks were presented in both visual and auditory modalities, and both real and non‐word stimuli were used. For each set of tasks stimuli were identical or closely matched, using phonetic criteria. Data was analysed for subjects within each age band, i.e. 3‐year‐olds, 4‐year‐olds, 5‐year‐olds, 6‐year‐olds and 7‐year‐olds. Analysis of variance revealed significant effects of age on all tasks. Comparisons were made of performance across the different presentations and stimuli‐type relevant to each task and significant effects of presentation and stimuli‐type were found for some tasks but not for all comparisons made. These findings allowed us to present a profile of normal development in performance across a range of input and output processing tasks. The time constraint prevents the full profile of results being included. However, the implications of the results for clinical practice will be presented. For example, given that normally developing children find non‐word repetition more difficult than real‐word repetition, at what point is the difference in performance on these tasks indicative of a motor programming deficit? Further, given the relationship between rhyme detection and production skills in normally developing children, at what age is the failure to produce any rhyming words significant? In summary, this study identified typical developmental profiles of phonological processing skills in children of 3–7 years of age. Speech and language therapists can use these results to identify with greater accuracy children with speech and language difficulties who may present with atypical psycholinguistic profiles. Subsequent therapy can be targeted in a more precise way.