Programming characteristics of cochlear implants in children: effects of aetiology and age at implantation

Objective: We investigated effects of aetiology and age at implantation on changes in threshold (T) levels, comfortable (C) levels and dynamic range (DR) for cochlear implants (CIs) in children over the first five years of life. Design: Information was collected at 6 months post-activation of CIs, and at 3 and 5 years of age. Study sample: One hundred and sixty-one children participating in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. Results: Children with neural and structural cochlear lesions had higher T-levels and C-levels as compared to those without these conditions. Parameter settings varied from manufacturer's defaults more often in the former than in the latter group. Investigation of the effect of age at implantation for children without neural and structural cochlear lesions showed that those implanted at <= 12 months of age had higher T-levels and narrower DR at 6 months post-activation, as compared to the later-implanted group. For both early- and later-implanted groups, the C-levels at 6 months post-activation were lower than those at age 3 and 5 years. There were no significant differences in T-levels, C-levels, or DR between age 3 and 5 years. Conclusions: Aetiology and age at implantation had significant effects on T-levels and C-levels.