The Role of Anatomy-Based Fitting in Bimodal Rehabilitation: Choosing Electrode Arrays Based on Cochlear Length

To evaluate the clinical impact of anatomy-based fitting (ABF) in cochlear implants for patients with asymmetric hearing loss.

Prospective cohort study.

Tertiary referral center specializing in hearing disorders.

Fifteen adult patients with asymmetric severe-to-profound sensorineural hearing loss or anacusis in the implanted ear, and residual low-frequency hearing (≤ 65 dB HL at 125-500 Hz) in the better ear, were enrolled. All underwent cochlear implantation with bimodal rehabilitation (cochlear implant + hearing aid) and completed a 12-month follow-up. Cochlear duct length was measured preoperatively using OTOPLAN software to select the appropriate electrode array. Postoperative CT scans were analyzed with OTOPLAN to verify electrode positioning and generate the ABF map. Speech intelligibility in noise was assessed using the Italian Matrix sentence test in three listening conditions, comparing outcomes between the ABF and the default MAESTRO fitting maps.

No statistically significant differences were found in speech perception scores between ABF and MAESTRO maps across test conditions. However, 86.7% of patients (13/15) preferred the ABF map for daily use, citing improved sound quality and listening comfort.

ABF, which aligns electrical stimulation with the patient's cochlear tonotopy by individualizing electrode selection and programming, may enhance the subjective auditory experience. While objective speech outcomes were comparable, patient preference strongly favored ABF, supporting its clinical relevance for optimizing cochlear implant performance in bimodal users.