Characterizing the Impact of Prolonged Deafness Duration on Cochlear Implantation Performance

To evaluate the impact of prolonged unaided duration of deafness (DoD) on speech perception outcomes following cochlear implantation in adults.

A retrospective review was performed of adult cochlear implant recipients at a single high-volume center between 2012 and 2023. Patients with ≥ 5 years of documented unaided deafness meeting cochlear implant (CI) criteria were stratified into three groups (5-9, 10-19, and ≥ 20 years DoD). The primary outcome was CNC word recognition scores at 3 and 12 months post-operatively.

Forty-one patients met inclusion criteria. At 3 months, patients with ≥ 20 years DoD demonstrated lower CNC word recognition scores compared with shorter duration groups. No significant differences were observed between groups at 12 months. Patients without measurable pre-operative hearing thresholds were more likely to be device non-users or fail to achieve open-set speech perception.

Patients demonstrated meaningful speech perception outcomes across a range of deafness durations, though longer DoD was associated with slower early improvement. Absence of measurable pre-operative hearing thresholds may identify a subgroup at higher risk for limited functional benefit and should be considered during pre-operative counseling.