Do vowel error patterns distinguish the speech of typically developing children to children with a phonological disorder or children with suspected Childhood Apraxia of Speech? A comparison of vowel errors produced by typically developing children, children with a phonological disorder and children with suspected apraxia of speech

Abstract

This research project takes the format of an extended research proposal designed to examine the validity of using vowel error patterns to support a differential diagnosis between typically developing children (TD), children with a phonological disorder (PD) and children with suspected Childhood Apraxia of Speech (sCAS). It proposes a cross-sectional empirical study comparing the vowel errors produced by two client groups: (i) children with a phonological disorder and (ii) children with suspected Childhood Apraxia of speech and compares them to the control group of typically developing children. Both the type and extent of error patterns and the consistency of production will be examined. Previous studies have examined the vowel errors of typical and clinical children and employed a range of methods of data collection, analysis and study designs, including single case studies, case series or single case groups. Despite this, there is, to the author's knowledge, no other study which directly compares the vowel productions of TD children to these two client groups using the same methodology. Given the claims in the literature that vowel errors might be a useful diagnostic feature - with more extensive errors, 'vowel distortions' and variable vowel patterns associated with sCAS - it is clear that the literature, and hence clinical diagnosis and decision making, would benefit from an empirical account of the extent and universality of any distinction between the groups.