Vocabulary growth from 18 to 24 months of age in children with and without repaired cleft palate

Purpose: This study investigated vocabulary growth from 18 to 24 months of age in young children with repaired cleft palate (CP), children with otitis media, and typically developing (TD) children. In addition, the contributions of factors such as hearing level, middle ear status, size of consonant inventory, maternal education level, and gender to the development of expressive vocabulary were explored. Method: Vocabulary size of 40 children with repaired CP, 29 children with otitis media, and 25 TD children was measured using the parent report on MacArthur-Bates Communicative Development Inventories: Words and Sentences (Fenson et al., 2007) at 18 and 24 months of age. All participants underwent sound field audiometry at 12 months of age and tympanometry at 18 months of age. A multiple linear regression with and without covariates was used to model vocabulary growth from 18 to 24 months of age across the 3 groups. Results: Children with CP produced a significantly smaller number of words at 24 months of age and showed significantly slower rate of vocabulary growth from 18 to 24 months of age when compared to TD children (p < .05). Although middle ear status was found to predict vocabulary growth from 18 to 24 months of age across the 3 groups (p < .05), the confidence interval was large, suggesting the effect should be interpreted with caution. Conclusions: Children with CP showed slower expressive vocabulary growth relative to their age-matched TD peers. Middle ear status may be associated with development of vocabulary skills for some children.