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

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.