Means and their standard error are shown (**p < 0.01, *p < 0.05, trends + p < 0.1).Īrdila A., Bernal B., Rosselli M. Regarding the spatial arrangement of speech and noise sources, the AEP condition is closest to S0NHA. While behavioral results from the AEP experiment at T3 and T4 did not evidence a significant difference between listening conditions, behavioral tests showed significantly better bimodal speech recognition at T3 for all test conditions and at T4 for the S0NCI condition. Due to insufficient monaural hearing, monaural data at T2 are only available for the AEP condition, where a significant difference existed between monaural and binaural listening.

Statistically significant differences between monaural listening with the CI or the designated CI ear in NH and binaural speech recognition was observed for several test conditions. Perception is best in NH listeners (A,B,G), worst shortly after CI provision (C,D,G) and improves with CI experience (E–G). Higher values signal better speech recognition in the FBE and AEP conditions, whereas lower values indicate better speech recognition in OlSa tests. Speech perception with FBE and OlSa tests (A–F) and assessed in the AEP experiment (G). Although the grand-averaged difference in N1 amplitude between monaural and binaural listening was similar for NH and the bimodal group, source localization showed group-dependent differences in auditory and speech-relevant cortex, suggesting different processing in the bimodal listeners.Īuditory evoked potentials auditory rehabilitation bimodal benefit cochlear implant electroencephalography hearing aid source localization speech recognition.Ĭopyright © 2020 Balkenhol, Wallhäusser-Franke, Rotter and Servais. Significant AEP differences between monaural and binaural processing were shown for NH and for bimodal listeners 6 month post-implantation. With CI experience, morphology of the N1 and P2 potentials in the AEP response approximated that of NH, whereas, N2 remained different. Moreover, a significant negative correlation existed between binaural summation and latency of the P2 potential. Some amount of binaural processing was suggested by a positive binaural summation effect 6 month post-implantation that correlated significantly with symmetry of pure tone thresholds. CI provision resulted in significant improvement of speech recognition with the CI ear, and in taking advantage of the head shadow effect for understanding speech in noise. Data of fifteen participants contributed to the results. Beyond that, bimodal benefit was estimated from the difference in amplitudes and latencies of the N1, P2, and N2 potentials of the brains' auditory evoked response (AEP) toward speech. The benefit of adding a contralateral hearing aid was calculated in terms of head shadow, binaural summation, binaural squelch, and spatial release from masking from the results of a sentence recognition test.

Results of these bimodal listeners were compared to age-matched, normal hearing controls (NH). Patients with bilateral sensorineural hearing loss undergoing implant surgery were tested in their ability to understand speech in quiet and in noise, before and again 3 and 6 months after provision of a CI.

It is uncertain, however, whether the brains of bimodal listeners can combine the electrical and acoustical sound information and how much CI experience is needed to achieve an improved performance with bimodal listening. With an extension of implantation candidacy, today many CI listeners use a hearing aid on their contralateral ear, referred to as bimodal listening. Cochlear implants (CI) improve hearing for the severely hearing impaired.

Hearing aid digital binaural