The "Symbiotic" Regulation Approach in Bimodal Hearing: Personal Experience in Adults

Introduction: Patients with bimodal auditory stimulation represent the largest group of cochlear implant users in many countries. The hearing results reported in the literature for subjects with bimodal hearing are controversial and often inadequate, since many cochlear implant recipients use hearing aids that are simply synchronized with their cochlear implant (“synchronized” regulation) and sometimes are even adapted independently of the cochlear implant (“classical” regulation). The purpose of this study was to verify that the innovative “symbiotic'' regulation of the cochlear implant and the dedicated hearing aid using an algorithm allows to achieve adequate rehabilitative hearing levels.

Methods: In total, 30 adult patients (12 females and 18 males; age range: 18-69 years) with bimodal hearing were enrolled in the present study and randomly divided into 3 groups of 10 subjects for each of the regulation modes (classical, synchronized, symbiotic) applied to adjust and pair the cochlear implant with the hearing aid. Statistical analysis of the hearing outcomes observed in the three groups was conducted using IBM SPSS V.29.0.0 statistical software. The setting was a tertiary/quaternary care referral center.

Results: The use of the symbiotic regulation approach with a digital bimodal regulation formula allowed significantly better hearing performance (p < 0.05) compared to that obtained with the classic or synchronous regulation, especially in difficult listening situations, for all subjects. Of the subjects with symbiotic bimodal regulation, 3 were able to successfully use the telephone already upon activation.

Conclusions: The symbiotic bimodal adjustment formula has provided significant hearing benefits and is confirmed as the ideal adjustment and coupling modality between the cochlear implant and the contralateral hearing aid.