Long-Term Language Development in Children With Early Simultaneous Bilateral Cochlear Implants

Abstract

Objectives: This longitudinal study followed the language development of children who received the combination of early (5 to 18 months) and simultaneous bilateral cochlear implants (CIs) throughout the first 6 years after implantation. It examined the trajectories of their language development and identified factors associated with language outcomes. Design: Participants were 21 Norwegian children who received bilateral CIs between the ages of 5 and 18 mo and 21 children with normal hearing (NH) who were matched to the children with CIs on age, sex, and maternal education. The language skills of these two groups were compared at 10 time points (3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 months after implantation) using parent reports and standardized measures of general language skills, vocabulary, and grammar. In addition, assessments were made of the effects of age at CI activation, speech recognition abilities, and mothers’ education on language outcomes 6 years after implantation. Results: During the first 4 years after implantation, the gap in general expressive and receptive language abilities between children with CIs and children with NH gradually closed. While at the initial five to six assessments (3 to 36 months after implantation), significant differences between children with CIs and children with NH were observed; at 4 years after implantation, there were no longer any significant group differences in general language skills and most children with CIs achieved scores within 1 SD of the tests’ normative means. From 2 to 3 years after implantation onward, expressive vocabulary and receptive grammar skills of children with CIs were similar to those of the reference group. However, from 4 years after implantation until the end of the observation period, 6 years after implantation, expressive grammar skills of children with CIs were lower than those of children with NH. In addition, a gap in receptive vocabulary appeared and grew increasingly larger from 4 to 6 years postimplantation. At the final assessment, the children with CIs had an average receptive vocabulary score around 1 SD below the normative mean. Regression analysis indicated that the children’s language outcomes at 6 years after implantation were related to their speech recognition skills, age at CI activation, and maternal education. Conclusions: In the first 4 years after implantation, the language performance of children with CIs became increasingly similar to that of their NH peers. However, between 4 and 6 years after implantation, there were indications of challenges with certain aspects of language, specifically receptive vocabulary and expressive grammar. Because these challenges first appeared after the 4-year assessment, the findings underline the importance of long-term language intervention to increase the chances of a continued language development comparable to that of NH peers. They also indicate that there is a need for com...

Language Development for the New Generation of Children with Hearing Impairment

“…Such conclusion would not have supported children with HI. Our results are aligned with results from a recent study [ 7 ] documenting that, over time, a gap in language performance seems to grow when children with HI are compared to normal hearing peers. This underlines the importance of carrying out longitudinal studies of children with all types and degrees of HI.…”

“…Therefore, it is important to keep monitoring pediatric populations with HI in terms of all aspects of audition and language development [ 6 ]. A recent study underlined this notion as it was found that early implanted children progressed really well in the first years after implantation, but after four years, a gap between children with CI as compared to children with NH started growing in terms of development of receptive vocabulary [ 7 ].…”

“…This shift in educational placement is highly cost-beneficial to society, and furthermore, is associated with better overall language outcomes for children with HI. Language outcomes refer to all aspects of language, e.g., vocabulary, grammatical and lexical understanding, pragmatics, and phonology [ 7 , 14 ]. Over the past decades, it has been documented that with early technical and educational intervention, children with HI are able to acquire language within the normal range [ 17 , 18 , 19 ].…”

The Input Matters: Assessing Cumulative Language Access in Deaf and Hard of Hearing Individuals and Populations

“…These values are commensurate with the findings of a large, longitudinal, population-based study in Australia (LOCHI; see Ching et al, 2010Ching et al, , 2018 for language outcomes at age 3 and 5, respectively). Equally concerning are recent findings from Norway (Wie et al, 2020), where all but two of the deaf children who received early, simultaneous, bilateral cochlear implants were followed from implantation through elementary school. Although not a large n, the data represent virtually the entire population.…”

“…For comparison, only about 16% of individuals in the reference population would be expected to score in that range: a risk ratio of 50/16 = 3.125, which equates to a 212.5% increase in risk relative to the reference population. Unfortunately, such scores are sometimes taken as evidence of success in studies of language outcomes in DHH children (e.g., Wie et al, 2020), rather than evidence that major disparities persist.…”