The Acquisition of Productive Plural Morphology by Children With Hearing Loss

Purpose Normal-hearing (NH) children acquire plural morphemes at different rates, with the segmental allomorphs /-s, -z/ (e.g., cat-s) being acquired before the syllabic allomorph /-əz/ (e.g., bus-es). Children with hearing loss (HL) have been reported to show delays in the production of plural morphology, raising the possibility that this might be due to challenges acquiring different types of lexical/morphological representations. This study therefore examined the comprehension of plural morphology by 3- to 7-year-olds with HL and compared this with performance by their NH peers. We also investigated comprehension as a function of wearing hearing aids (HAs) versus cochlear implants (CIs). Method Participants included 129 NH children aged 3-5 years and 25 children with HL aged 3-7 years (13 with HAs, 12 with CIs). All participated in a novel word two-alternative forced-choice task presented on an iPad. The task tested comprehension of the segmental (e.g., teps, mubz) and syllabic (e.g., kosses) plural, as well as their singular counterparts (e.g., tep, mub, koss). Results While the children with NH were above chance for all conditions, those with HL performed at chance. As a group, the performance of the children with HL did not improve with age. However, results suggest possible differences between children with HAs and those with CIs, where those with HAs appeared to be in the process of developing representations of consonant-vowel-consonant singulars. Conclusions Results suggest that preschoolers with HL do not yet have a robust representation of plural morphology for words they have not heard before. However, those with HAs are beginning to access the singular/plural system as they get older.