Morphological Accuracy in the Speech of Bimodal Bilingual Children with CIs.

Sign language use in the (re)habilitation of children with cochlear implants (CIs) remains a controversial issue. Concerns that signing impedes spoken language development are based on research comparing children exposed to spoken and signed language (bilinguals) to children exposed only to speech (monolinguals), although abundant research demonstrates that bilinguals and monolinguals differ in language development. We control for bilingualism effects by comparing bimodal bilingual (signing-speaking) children with CIs (BB-CI) to those with typical hearing (BB-TH). Each child had at least one Deaf parent and was exposed to ASL from birth. The BB-THs were exposed to English from birth by hearing family members, while the BB-CIs began English exposure after cochlear implantation around 22-months-of-age. Elicited speech samples were analyzed for accuracy of English grammatical morpheme production. Although there was a trend toward lower overall accuracy in the BB-CIs, this seemed driven by increased omission of the plural -s, suggesting an exaggerated role of perceptual salience in this group. Errors of commission were rare in both groups. Because both groups were bimodal bilinguals, trends toward group differences were likely caused by delayed exposure to spoken language or hearing through a CI, rather than sign language exposure.