Long-term Outcome After Cochlear Implantation in Children With Single-sided Deafness

Objective: To determine long-term audiological and subjective outcomes of cochlear implantation in children with congenital single-sided deafness (SSD), with emphasis on factors potentially influencing the degree of benefit. Study design: Retrospective single-center study. Setting: Tertiary referral center. Subjects: Twenty congenitally deaf children with a mean age at implantation of 2.6 (±1.7) years and a mean cochlear implant (CI) experience of 6.8 (±3.2) years were included. Intervention: Unilateral cochlear implantation. Main outcome measure: Assessment of speech understanding in quiet (Freiburger/Göttinger/Mainzer tests) and in noise (OLSA/OLKiSA), sound localization ability (RMS, MAE), subjective assessments by parents and children adapted to the developmental age (SSQ, E-HAK, Bochum questionnaires), and CI usage time. Results: Significant improvements were observed in speech in noise with speech from the implanted and noise from the normal hearing side (SNR 1.08 dB without vs. −1.67 dB with CI, P =0.0021), in sound localization measured by RMS (69.76 degrees without vs. 52.38 degrees with CI, P =0.0040), and in the subjective assessment using the SSQ ( P <0.005) and the E-HAK ( P =0.018). No clear correlation was found between the subjective rating by parents or children and the objective benefits with the implant. There was considerable interindividual variability in outcome, which could not be explained solely by age at implantation, duration of CI usage, or CI experience. Conclusion: Although the CI is predominantly rated positively by parents and children, a thorough counseling regarding the anticipated benefits is required. Multicenter studies with well-documented data on potential influencing factors will provide greater clarity in the future.