Cochlear Implantation in Cases of Asymmetric Hearing Loss: Subjective Benefit, Word Recognition, and Spatial Hearing

Abstract

A prospective clinical trial evaluated the effectiveness of cochlear implantation in adults with asymmetric hearing loss (AHL). Twenty subjects with mild-to-moderate hearing loss in the better ear and moderate-to-profound hearing loss in the poorer ear underwent cochlear implantation of the poorer hearing ear. Subjects were evaluated preoperatively and at 1, 3, 6, 9, and 12 months post-activation. Preoperative performance was evaluated unaided, with traditional hearing aids (HAs) or with a bone-conduction HA. Post-activation performance was evaluated with the cochlear implant (CI) alone or in combination with a contralateral HA (bimodal). Test measures included subjective benefit, word recognition, and spatial hearing (i.e., localization and masked sentence recognition). Significant subjective benefit was reported as early as the 1-month interval, indicating better performance with the CI compared with the preferred preoperative condition. Aided word recognition with the CI alone was significantly improved at the 1-month interval compared with preoperative performance with an HA and continued to improve through the 12-month interval. Subjects demonstrated early, significant improvements in the bimodal condition on the spatial hearing tasks compared with baseline preoperative performance tested unaided. The magnitude of the benefit was reduced for subjects with AHL when compared with published data on CI users with normal hearing in the contralateral ear; this finding may reflect significant differences in age at implantation and hearing sensitivity across cohorts.

Middle-term cochlear implant use in case of asymmetric hearing loss and single-sided deafness: A retrospective single-centre cohort study

“…This study shows a small rate of non-users at 1-year post-implantation among post-lingually deaf adults CI recipients (1.4 %), a percentage similar to that reported in the literature (4,5). At 5-years post-implantation, 4 out of the 6 patients with SSD still used their CI (67%).…”

“…Demographic data and audiometric evaluation of 72 patients (66 AHL, 6 SSD) are reported in Table 1. The mean follow up was 3 +-1.8 years [1][2][3][4][5][6][7]. Only three AHL candidates did not use a hearing aid on the acoustic-hearing ear: two cases with mild hearing loss (PTA: 33 and 35 dB, respectively) and one vestibular schwannoma.…”

Comparison of Speech Test Outcomes After Cochlear Implantation in Patients With and Without Asymmetric Hearing Loss

“…While many studies indicate promising outcomes for implantation of adults with AHL, there are limited studies that assess how individuals with AHL compare to traditional CI candidates in the same sample population (4,9,11,(15)(16)(17)(18). In this study, we investigated whether speech outcomes in the implanted ear differ over time between traditional CI candidates with bilateral unserviceable hearing loss versus CI candidates with AHL.…”

Guidelines for cochlear implantation in Saudi Arabia

“… 33 In this group of patients, the objective is to restore bimodal auditory stimulation (hearing aid in the better ear and CI in the worse ear). 20 , 34 , 35 Both adults and children can be candidates for this mode of stimulation. Candidacy for CI would be as follows: i) Severe to profound hearing loss in the conversational frequencies (1-4 kHz) in the ear with the worse hearing capacity.…”