Identification and Evaluation of Cochlear Implant Candidates with Asymmetrical Hearing Loss

Abstract

Objective: Recommendation for cochlear implant (CI) treatment for individuals with severe to profound single-sided deafness (SSD) and asymmetrical hearing loss (AHL) is on the rise. This raises the need for greater consistency in the definition of CI candidacy for these cases and in the assessment methods of patient-related benefits to permit effective comparison and interpretation of the outcomes with both conventional and implantable options across studies. Method: During a dedicated seminar on implant treatment in AHL patients, the panellists of the closing round table reviewed the clinical experience presented with the aim to define clear audiometric characteristics for both AHL and SSD cases, as well as a common data set enabling consistent evaluation of hearing benefits in this population. Conclusions: The panellists agreed on a clear differentiation between AHL and SSD CI candidates, defining average pure-tone thresholds up to 4 kHz for better and poorer ears. Agreement was reached on a minimum set of assessment procedures, and included the necessity of trials with conventional CROS/BICROS hearing aids and bone conduction devices before considering CI treatment. Objective assessment of sound localisation abilities was identified as the most relevant criterion to quantify performance before and after treatment. In parallel, subjective assessment of overall hearing ability was recommended via the Speech, Spatial and Qualities of hearing questionnaire. Longitudinal follow-up of these parameters and the hours of daily use were considered essential to reflect the potential treatment benefits for this population. The consistency in the data collection and its report will further support health authorities in their decision on acceptable gains from available hearing loss treatment options.