An evaluation of hearing preservation outcomes in routine cochlear implant care: Implications for candidacy

Abstract

Introduction: A retrospective evaluation of pre- and post-operative audiometric data at a single large UK cochlear implant centre over 25 years was undertaken. Methods: Analysis of pre-operative hearing levels showed that there was a modest but significant reduction in average pre-operative hearing thresholds among patients referred between 1990 and 2015, particularly in the low frequencies. Outcomes: The proportion of those referred who would meet widely-accepted candidacy criteria for electroacoustic stimulation (EAS) grew significantly over time but in the period 2011-2015 just 9% of those referred had sufficient residual hearing for EAS. On average, implant recipients lost 20 dB hearing at frequencies ≤1000 Hz as a result of the surgery. Conclusions: The findings suggest that hearing preservation is now widely achievable, and that both candidacy criteria and referrer education should take into account potential EAS benefit.