Word and world knowledge among deaf learners with and without cochlear implants.

Deaf learners frequently demonstrate significantly less vocabulary knowledge than hearing age-mates. Studies involving other domains of knowledge, and perhaps deaf learners' academic performance, indicate similar lags with regard to world knowledge. Such gaps often are attributed to limitations on deaf children's incidental learning by virtue of not having access to the conversations of others. Cochlear implants (CIs) have been described as providing such access, and rapid growth in vocabularies following pediatric cochlear implantation has suggested that, over time, children with implants might close the gap relative to hearing peers. Two experiments evaluated this possibility through the assessment of word and world knowledge among deaf college students with and without CIs and a hearing comparison group. Results across essentially all tasks indicated hearing students to outperform deaf students both with and without CIs with no significant differences between the latter two groups. Separate analyses of a subset of implant users who received their implants at a young age did not reveal any long-term advantages, nor was age of implantation related to enhanced performance on any of the tasks. Results are discussed in terms of incidental learning and the accessibility of word and world knowledge to deaf learners with and without CIs.