Age or Experience? The Influence of Age at Implantation and Social and Linguistic Environment on Language Development in Children With Cochlear Implants

Purpose: The authors investigated the influence of social environmental variables and age at implantation on language development in children with cochlear implants. Method: Participants were 25 children with cochlear implants and their parents. Age at implantation ranged from 6 months to 42 months (M-age = 20.4 months, SD = 22.0 months). Linguistic progress was assessed at 12, 18, 24, and 30 months after implantation. At each data point, language measures were based on parental questionnaire and 45-min spontaneous speech samples. Children's language and parents' child-directed language were analyzed. Results: On all language measures, children displayed considerable vocabulary and grammatical growth over time. Although there was no overall effect of age at implantation, younger and older children had different growth patterns. Children implanted by age 24 months made the most marked progress earlier on, whereas children implanted thereafter did so later on. Higher levels of maternal education were associated with faster linguistic progress; age at implantation was not. Properties of maternal language input, mean length of utterance, and expansions were associated with children's linguistic progress independently of age at implantation. Conclusions: In children implanted within the sensitive period for language learning, children's home language environment contributes more crucially to their linguistic progress than does age at implantation.