Phonological mean length of utterance in specific language impairment: a multi-case study of children acquiring Finnish

Abstract

This study assesses the phonological development of four Finnish-speaking children (ages 4;8, 4;9, 4;9 and 5;5) with specific language impairment (SLI) and dyspractic features in speech. The analysis is performed using the phonological mean length of utterance (pMLU) method. Moreover, the children's phonological abilities are evaluated qualitatively in relation to segments, phonotactics and word structure. The results are compared with those obtained from four age-matched typically developing peers and with the data from an earlier study using the pMLU method on younger, typically developing Finnish children. In the pMLU analysis, the children with SLI performed roughly at the level of typically developing 2-year-old children. The qualitative analyses revealed that children with SLI had difficulties in producing word-medial clusters and word-initial consonants and that they exhibited frequent consonant assimilations, infrequent errors and vowel errors. The pMLU method did differentiate between children with SLI and typically developing children. However, qualitative analyses revealed some weaknesses of the pMLU method when assessing Finnish children with SLI.

Keywords:

• phonology
• specific language impairment
• phonological mean length of utterance
• childhood apraxia of speech

Acknowledgements

The research reported here was supported by research grant R01 DC00458 from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health, and by the Academy of Finland. The authors thank the anonymous reviewers for their helpful comments on an earlier version of this paper.

Notes

1. A clear majority of the studies on children with SLI have had their focus on children acquiring English. The results reported here are from studies on children acquiring English, unless otherwise stated.

2. The relationship between motor deficits and SLI is contentious (see, e.g. Bishop, 2004; Hill, 2001, 2010; Iverson, 2010; Leonard, 1998).

3. For the word identification criteria, see Vihman and McCune (1994).

4. Correct vowels are not scored in the pMLU counts, although we also know that in children with SLI, especially with dyspractic features, vowel errors are frequent (see, e.g. Forrest, 2003).