Long-Term Preservation of High-Frequency Hearing After Cochlear Implantation in a Child with Substantial Residual Hearing: A Case Report

Background/Objectives: Cochlear implantation (CI) in children with substantial residual hearing remains challenging because of the risk of hearing loss. Partial deafness treatment and hearing preservation have traditionally focused on functionally useful low-frequency hearing, while residual hearing in the high-frequency range has not been specifically addressed in established classifications. Long-term data on preservation of substantial high-frequency residual hearing after CI in children remain limited. We present a pediatric case demonstrating 5-year preservation of high-frequency residual hearing after CI. Methods: A 14-year-old girl with bilateral sensorineural hearing loss underwent left CI with a MED-EL FLEX 28 electrode inserted through the round window. Pure-tone thresholds were assessed preoperatively and at 1, 12, 24, and 60 months postoperatively. Hearing preservation was evaluated using the Skarzynski classification, and speech perception was assessed before implantation and at 24 months. Results: Preoperatively, air-conduction thresholds were ≤70 dB HL at 2000–8000 Hz. Overall hearing preservation was complete at 1, 12, and 24 months and partial at 60 months. Importantly, hearing preservation at 2000–8000 Hz remained complete throughout the 60-month follow-up, with S-values of 90.7%, 76.7%, 79.1%, and 76.7%, respectively. At 24 months, word recognition in the implanted ear improved by 35 percentage points in quiet and 70 percentage points in noise compared with the preoperative aided condition. Conclusions: This case demonstrates 5-year preservation of substantial high-frequency residual hearing after CI in an adolescent with an atypical preoperative hearing profile. These findings suggest that cochlear implantation may be considered in selected patients with substantial residual hearing when conventional hearing aids provide insufficient functional benefit. However, broader conclusions regarding cochlear implant candidacy cannot be drawn from a single case.