Conclusion: The use of a hearing aid (HA) in combination with a cochlear implant (CI) significantly improved performance for speech perception in quiet, in noise, and for localization compared with monaural conditions. No significant differences in functional performance were observed following optimization of HA fitting.
Objectives: To evaluate the binaural benefits derived from using a contralateral HA in conjunction with a CI in subjects with significant functional hearing in the nonimplanted ear and the effects of HA fitting optimization.
Methods: Fifteen adult CI users, intra-subject controls, were enrolled in a prospective repeated-measure multicenter study. Evaluation of performance for speech understanding, localization, and subjective impressions was conducted before and following HA fitting optimization for CI alone, HA alone, and CI + HA.
Results: For speech testing in quiet, bimodal scores were significantly better than for HA alone and CI alone conditions (p < 0.01). For speech and noise (S0N0) at 0° azimuth the scores were significantly better in the bimodal condition than for CI alone (p = 0.01), indicating binaural summation. When noise was presented to the HA side (S0NHA) bimodal scores were significantly better than for CI alone (p < 0.01 and p < 0.05, respectively), suggesting a significant binaural squelch effect. Sound localization ability was significantly improved in the bimodal condition compared with the CI alone condition (p = 0.002).