Predicting speech perception outcomes following cochlear implantation in adults with unilateral deafness or highly asymmetric hearing loss

Pádraig T Kitterick,Laura Lucas

doi:10.1080/14670100.2016.1155806

Abstract

Objective: Unilateral deafness and highly asymmetric hearing loss can impair listening abilities in everyday situations, create substantial audiological handicap, and reduce overall quality of life. Preliminary evidence suggests that cochlear implantation may be effective in reversing some of these detrimental effects. Patient-level data from existing studies were re-analysed to explore potential factors that may be predictive of improved speech perception scores following implantation.Methods: Logistic regression modelling examined whether improved speech perception following implantation under various listening conditions was related to the duration of deafness of the severe-to-profoundly deaf ear and/or the level of hearing in the better ear.Results: Patients with a shorter duration of deafness were more likely to improve in listening conditions that created a less favourable SNR at the implanted ear than the non-implanted ear. Those with more residual hearing in the better ear were more likely to improve in the listening condition that created a less favourable SNR at that ear.Discussion: The analysis suggests that characteristics of both ears may be relevant when seeking to identify those candidates who are likely to obtain benefit to speech perception following cochlear implantation.

Highlights

Access to hearing in one ear only can create difficulties with listening in most everyday environments (Dwyer et al, 2015)
Extraction of outcome data Previous studies have assessed the perception of sentences in noise in three categories of listening condition defined by the relative difference between the signal-to-noise ratio (SNR) at the impaired/implanted ear (IE) and the non-implanted ear (NE): (1) when the SNR at the two ears are similar (IE=NE); (2) when the SNR is more favourable at the impaired ear (IE>NE); and (3) when the SNR is more favourable at the non-implanted ear (IE
The analysis indicated that those with a shorter duration of deafness in the severe-to-profoundly deaf ear prior to implantation were more likely to improve in the listening condition that created the leastfavourable SNR at the implanted ear (IE

Summary

Introduction

Access to hearing in one ear only can create difficulties with listening in most everyday environments (Dwyer et al, 2015). This absence of auditory input leads to difficulties with understanding speech when the talker of interest is on the impaired side and in determining the location of sounds. Emerging evidence from early-phase studies suggests that cochlear implantation may be an effective way to improve listening skills impaired by unilateral deafness (Blasco & Redleaf, 2014; van Zon et al, 2015) and to alleviate the associated burden (Kitterick et al, 2015). The evidence for implantation in unilaterally-deaf patients is limited to a few observational studies and it is as yet unclear what factors may determine whether a patient is likely to receive benefit or not. A meta-analysis which pools the small samples of unilaterally-deaf patients that have been assessed in existing studies could provide sufficient statistical power to identify potential factors that could subsequently be evaluated prospectively in future studies

Methods

Results

Conclusion