Abnormal vowel patterns in phonological disorder: some data and a hypothesis

This article examines the vowel systems of a group of phonologically disordered children who show abnormalities in their vowel patterns. The conclusions emerging from the analysis of disordered speech are presented, along with examples from the data. It is argued that there are relatively common context-free processes of simplification of the vowel system in the data, and that these represent natural changes that may occur in normal development. Other less common processes may be idiosyncratic, and indicate some measure of disordered development. Some difficulties with vowels may relate to difficulties in the consonant system, or to difficulties with prosodic or paralinguistic features. Variability is an important part of the data, relevant to understanding the disorder and the process of development. It is hypothesised that the proposed framework will be relevant to clinical decision-making.