Introduction: Hearing results after cochlear implantation (CI) vary significantly between patients. Prolonged duration of deafness (DoD) has been described as a negative predictive factor for hearing rehabilitation. However, most studies include a variety of etiologies and rely on approximated or self-reported onset of deafness leading to uncertain DoD estimations. We therefore analyzed only patients after idiopathic sudden sensorineural hearing loss (SSNHL) to more accurately estimate the impact of DoD on hearing outcome after CI.

Methods: Data sets of adult patients who underwent cochlear implantation after SSNHL between 2008 and 2022 at the University Hospital Oldenburg were retrospectively analyzed. Word recognition scores (WRS) of the Freiburger monosyllabic speech test were assessed at 12 months after surgery. Duration of deafness, demographic data, and preoperative audiometric data were analyzed regarding their impact on hearing results with CI.

Results: We included 57 adult patients (68% SSD, 32% AHL) with a mean DoD of 44.8 (range: 3-365) in this study. The mean age at implantation was 56.7 (15-83) years. Mean WRS was 63% (5-100%) at 12 months after surgery. Spearman"s rank correlation analysis did not show a significant correlation between DoD and CI outcome. Multivariable linear regression analysis of demographic and preoperative audiometric data did not identify any significant predictor for hearing outcome.

Conclusion: Our study did not find a negative impact of prolonged duration of deafness on hearing outcome after CI. However, larger multicenter studies are needed to reliably investigate the impact of DoD. So far, prolonged postlingual deafness should not be a reason for excluding patients from CI.

RS received travel costs compensation and course fees from MedEL. RB received travel costs compensation and course fees from MedEL and Cochlear. AR received travel cost compensation from MedEL.