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

Abstract

Objectives:Determine whether asymmetric hearing loss (AHL) affects postoperative speech outcomes in cochlear implant (CI) patients.Study Design:Retrospective cohort study.Setting:Tertiary care hospital.Patients:Adult English-speaking patients with unilateral CIs implanted between 2014 and 2018 were stratified into NonAHL and AHL groups based on preoperative AzBio scores in quiet from the nonimplanted ear (0–50% vs. 51–100%, respectively).Interventions:CI surgery in the poorer performing ear.Main Outcome Measures:Postoperative consonant-nucleusconsonant (CNC) word and AzBio sentence test scores in quiet and/or noise at +5 dB signal-to-noise ratio (SNR).Results:Of 512 patients, 33 non-AHL and 27 AHL patients were included. Average ages were 65.6 and 63.6 years, respectively. As expected, preoperative AzBio scores in quiet from the nonimplanted ear were higher in the AHL group (95% confidence interval [95%CI]: 66.4–76.4%) than the non-AHL group at baseline (95%CI: 12.3–23.6%). In both cohorts, AzBio scores in quiet from the implanted ear improved from baseline, with 24-month scores (95%CI: 73.8 - 84.9%) being higher than preoperative scores (95%CI: 13.2–23.1%). There were also significant differences in AzBio scores in quiet between cohorts overall (p = 0.0120) on mixed model analysis, with the AHL group performing ∼6.4% better than the non-AHL group; however, differences were not significant when scores were stratified by time. In addition, there were no significant differences in CNC in quiet and AzBio scores in noise at +5 dB SNR between cohorts (p = 0.1786 and p = 0.6215, respectively).Conclusions:After CI, patients with AHL can achieve scores on word and sentence tests at least comparable to traditional CI candidates, supporting the expansion of CI candidacy to include patients with AHL.

Asymmetric Hearing Loss in Adult Cochlear Implant Recipients: Results and Recommendations From a Multisite Prospective Clinical Trial

“…Present study participants all had hearing loss in the contralateral ear (mean 4fPTA of 56.6 dB HL; SD 9.5) and similar postimplant CI CNC60 scores to traditional CI recipients. This result is comparable to that found by Misztal et al (2022) who retrospectively examined postimplant CI word scores in two groups, individuals with AHL and without AHL (i.e., traditional CI recipients). Those with AHL had preimplant AzBio sentence scores between 51% and 100% and a PTA of 62.1 dB HL in the contralateral, nonimplant ear.…”

Cochlear implantation for paediatric and adult cases of unilateral and asymmetric hearing loss

“…There are discrepancies across studies on this topic. Most studies report speech recognition performance as similar between the UHL/AHL and traditional cochlear implant groups [24,31,32], though one study reports that traditional cochlear implant users achieve higher scores in the implanted ear within the first year of use [33]. Although the assessment of monaural hearing abilities is typically conducted clinically and as part of research investigations, improved speech recognition in the poorer hearing ear is not the main reason for pursuing cochlear implantation for patients with UHL/AHL, as previously discussed by Deep et al [24].…”