A Multicenter Study of Cochlear Implantation in Adults With Prolonged Unilateral Deafness

To evaluate cochlear implant (CI) speech perception and usage outcomes in patients after prolonged unilateral deafness.

Retrospective cohort study at five tertiary academic centers of adult patients with prolonged (> 10 years) unilateral severe to profound hearing loss who underwent cochlear implantation. Main outcome measures included post-operative word recognition scores (WRSs) and average daily usage of CI.

A total of 68 patients were analyzed with a median duration of unilateral deafness of 17 years (IQR, 12-35 years). The mean individual average daily CI usage was 8.4 h (SD, 4.5 h) at ≤ 1 year after implantation and 7.1 h (SD, 5.0 h) at > 1 year. The majority of patients (54.5%, 30 patients) had an absolute increase in WRS of ≥ 20% after implantation and 32.7% (18 patients) had an absolute increase of ≥ 50%. Univariate analysis comparing pre- and post-operative speech recognition in patients who completed the same test revealed a clinically and statistically significant improvement, with a mean change of 28.4% (SD 31.6%; p < 0.001) at their latest audiogram. In the analysis excluding those without post-operative data, duration of deafness was not predictive of post-CI WRS on multivariable analysis.

Most patients with prolonged unilateral auditory deprivation in our study benefited from a CI. Although the duration of auditory deprivation was found to be inconsistently associated with poorer CI speech perception performance, our findings support individualized CI candidacy assessment and suggest that prolonged deafness alone should not be used as an absolute exclusion criterion for cochlear implantation.