Linguistic complexity of speech recognition test sentences and its influence on children's verbal repetition accuracy

Objectives: Speech recognition (SR)-tests have been developed for children without considering the linguistic complexity of the sentences used. However, linguistic complexity is hypothesized to influence correct sentence repetition. The aim of this study is to identify lexical and grammatical parameters influencing verbal repetition accuracy of sentences derived from a Dutch SR-test when performed by 6-year-old typically developing children. Design: For this observational, cross-sectional study, 40 typically developing children aged 6 were recruited at four primary schools in the Netherlands. All children performed a sentence repetition task derived from an SR-test for adults. The sentence complexity was described beforehand with one lexical parameter, age of acquisition, and four grammatical parameters, specifically sentence length, prepositions, sentence structure, and verb inflection. A multiple logistic regression analysis was performed. Results: Sentences with a higher age of acquisition (odds ratio [OR] = 1.59) or greater sentence length (OR = 1.28) had a higher risk of repetition inaccuracy. Sentences including a spatial (OR = 1.25) or other preposition (OR = 1.25) were at increased risk for incorrect repetition, as were complex sentences (OR = 1.69) and sentences in the present perfect (OR = 1.44) or future tense (OR = 2.32). Conclusions: The variation in verbal repetition accuracy in 6-year-old children is significantly influenced by both lexical and grammatical parameters. Linguistic complexity is an important factor to take into account when assessing speech intelligibility in children.