Expressive vocabulary of school-age children with mild to moderately severe hearing loss.

Objectives: The main goal of this study was to describe the expressive vocabulary of school-age children with mild to moderately severe hearing loss (CHL group) and to compare their performance with children with normal hearing (CNH group) of the same age. Another aim was to examine the interaction between nonword repetition and expressive vocabulary size. Furthermore, the interaction between results on vocabulary tests and background factors, such as the age of diagnosis, age of hearing aid fitting, and amount of hearing aid use, was explored.

Method: School-aged children with mild to moderately severe, permanent bilateral hearing loss and children with normal hearing were included in this cross-sectional study. The children participated in assessments of naming pictures, defining words, and repetition of nonwords and sentences. Results of the CHL group and the CNH group were compared. The analysis also included the degree of hearing loss, the age of diagnosis, amount of hearing aid use, and level of parental education.

Results: The CHL group performed significantly below the CNH group on all measures: picture naming, defining words, nonword repetition, and repetition of sentences. The proportion of words pronounced with correct phonological structure when picture naming was more limited in the CHL group than in the CNH group. There was a significant positive correlation between the amount of hearing aid use and nonword repetition ability in the CHL group. Age of diagnosis and age of hearing aid fitting was not significantly correlated with the outcomes of the vocabulary assessments in this study.

Conclusion: Despite the technological advancement of hearing aids, the expressive vocabulary in school-aged children with mild to moderately severe, permanent bilateral, hearing impairment does not reach the same level as for children with normal hearing, although there is a variation in performance within the group. The variation in the CHL group was not uniquely impacted by either age, degree of hearing loss, or the age of diagnosis. The amount of hearing aid use seems to impact the perception of new words. More studies of expressive vocabulary are needed, because they capture a dimension of word learning that seems particularly sensitive to hearing loss and hearing aid use.