Integrated Bimodal Fitting for Unilateral CI Users with Residual Contralateral Hearing.

BACKGROUND: The aim of this study was to compare, in users of bimodal cochlear implants, the performance obtained using their own hearing aids (adjusted with the standard NAL-NL1 fitting formula) with the performance using the Phonak Naìda Link Ultra Power hearing aid adjusted with both NAL-NL1 and a new bimodal system (Adaptive Phonak Digital Bimodal (APDB)) developed by Advanced Bionics and Phonak Corporations. METHODS: Eleven bimodal users (Naìda CI Q70 + contralateral hearing aid) were enrolled in our study. The users' own hearing aids were replaced with the Phonak Naìda Link Ultra Power and fitted following the new formula. Speech intelligibility was assessed in quiet and noisy conditions, and comparisons were made with the results obtained with the users' previous hearing aids and with the Naída Link hearing aids fitted with the NAL-NL1 generic prescription formula. RESULTS: Using Phonak Naìda Link Ultra Power hearing aids with the Adaptive Phonak Digital Bimodal fitting formula, performance was significantly better than that with the users' own rehabilitation systems, especially in challenging hearing situations for all analyzed subjects. CONCLUSIONS: Speech intelligibility tests in quiet settings did not reveal a significant difference in performance between the new fitting formula and NAL-NL1 fittings (using the Naída Link hearing aids), whereas the performance difference between the two fittings was very significant in noisy test conditions.

Very good performance with bimodal stimulation in a like-hybrid modality in a patient with profound bilateral sensorineural hearing loss with low-frequencies preservation.

In this work we describe the experimental protocol set up to obtain very good results in speech performance and in time course, with a subject presenting profound bilateral sensorineural hearing loss with low-frequencies preservation. We used a bimodal stimulation with a like-hybrid modality. Auditory functions have been analyzed by standard tonal and speech audiometry tests, and verbal perception test. The fitting protocol permitted the subject to reach a perception at 65 dB of 100% in a very short time. The subject showed a sufficient recovery of the language spectral information and a good integration of verbal information with high consonantal recognition is present. This case report shows the importance to realize a correct cochlear implant fitting and that, in the case of bimodal stimulation, it is very important to obtain the mutual adjustment of the two hearing aids. Moreover, this study enhances the importance of realizing a preservative surgery to make the most of cochlear implants capacity.