Is there a right cochlear implant advantage?

OBJECTIVE: To compare behavioral speech perception performance of children with right versus left cochlear implants (CIs).

STUDY DESIGN: A retrospective cohort study.

SETTING: Academic university medical center.

SUBJECTS: Seventy-one prelingually deafened children that obtained a CI device at 48 months or younger.

INTERVENTION: Cochlear implantation with Cochlear, Advanced Bionics, and Med-El devices.

MAIN OUTCOME MEASUREMENTS: Patients were divided into 2 groups according to ear of implant (right, n = 30; left, n = 41) and matched in age at implantation and preoperative audiologic results. Multivariate analysis of variance was used to evaluate the effects of 1) side of CI, 2) age at implantation, 3) time with CI (T1, 18-24 mo; T2, 36-42 mo), and 4) dominance (i.e., compatibility between CI side and handedness) on performance in a monosyllabic open-set test scored for words and phonemes.

RESULTS: A small yet significant "right CI advantage" was evident throughout the study follow-up and was independent of age at implantation. The performance of children implanted at 24 months or younger was significantly higher than that of children implanted between 25 and 48 months. Regardless of CI side and age at implantation, all children exhibited improvement in speech perception with continuous use.

CONCLUSION: The present study provides first-time evidence for a right CI advantage for speech perception in prelingually deafened children that can be taken into account when selecting side of CI in candidates with similar residual hearing in both ears and no anatomic constraints. The present data lend further support to the notions that greater gains in speech perception are associated with earlier age at implantation and continuous use.