Binaural Hearing in Bilateral Cochlear Implant Users: Electrophysiological and Clinical Correlation

Background: The main indication for bilateral cochlear implants (CIs) is the range of binaurality, a skill that allows sound localization and better auditory perception and discrimination in noisy environments. The presence of binaural hearing can be demonstrated electrophysiologically by the binaural interaction component (BIC) and clinically by the Hearing in Noise Test (HINT). Objective To analyze the correlation between latencies and amplitudes of the BIC of the cortical auditory evoked potential (BIC-CAEP) and HINT performance in bilateral CI users. Methods Pilot study consisted of 27 individuals with bilateral Cis in cochlear implant group (CIG), and the control group (CG) consisted of 22 volunteers with normal hearing. The latencies and amplitudes of the P1 and N1 components of the BIC-CAEP, auditory effort by a visual analog scale (VAS) and performance in the fixed and adaptive HINT were investigated. The results were compared between groups. Results There was a statistically significant difference between the CIG and CG in terms of VAS score of fixed HINT, performance in adaptive HINT, N1 and P1 amplitude of the BIC-CAEP. There was a significant correlation between the fixed HINT performance and the P1 amplitude of the BIC-CAEP. Conclusion Results of the present study demonstrated that lower P1 amplitude of the BIC-CAEP was correlated with best clinical performance in the fixed HINT.