Speech comprehension in children and adolescents after sequential bilateral cochlear implantation with long interimplant interval

Objective: Identify likely predictors for the outcome after contralateral cochlear implantation with a long interimplant delay. Study Design: Retrospective case reviews. Setting: Outpatient cochlear implant (CI) center. Patients: Seventy-three children and adolescents who underwent sequential bilateral cochlear implantation with an interval between both implantations of 5 years or longer. The mean age of the patients at the first and second cochlear implantations was 2.72 ± 1.52 and 11.57 ± 2.9 years, respectively. The mean duration of experience with both implants was 4.01 ± 1.57 years. Intervention: Rehabilitative. Main Outcome Measures: All 73 patients underwent periodic speech perception testing in quiet and noise. The most recent unilateral data for each side were statistically analyzed. The speech test results were evaluated by the age at first implantation, the interval between both implantations, the duration of hearing aid use in the second side, and the duration of the bilateral CI use. Results: A statistically significant difference for speech test results was obtained between the early-implanted ears and the late-implanted ears for all children. These results were dependent on the interimplant interval. All age groups demonstrated significant differences (p > 0.05) for the second side between the speech test results and the interval between both cochlear implantations. In addition, statistically significant differences influenced by the duration of hearing aid use were found for speech test results for the second side. Experience was also a factor for the second CI, yielding significantly higher speech test scores with longer use. Conclusion: The development of hearing abilities in a secondimplanted side depends on the interimplant interval, the hearing aid use, and the duration of the second CI use.