Long‐term audiologic outcomes after cochlear implantation for single‐sided deafness

Abstract

Objectives To evaluate the long‐term audiometric outcomes, sound localization abilities, binaural benefits, and tinnitus assessment of subjects with cochlear implant (CI) after a diagnosis of unilateral severe‐to‐profound hearing loss. Method The study group consisted of 60 (mean age 52 years, range 19–84) subjects with profound hearing loss in one ear and normal to near‐normal hearing in the other ear who underwent CI. Data analysis included pre‐ and postoperative Consonant‐Nucleus‐Consonant (CNC) Word scores, AzBio Sentence scores, pure tone thresholds, sound localization, and Iowa Tinnitus Handicap Questionnaire scores. Results Preoperative average duration of deafness was 3.69 years (standard deviation 4.31), with an average follow‐up time of 37.9 months (range 1–87). CNC and AzBio scores significantly improved (both P < 0.001) postoperatively among the entire cohort, and there was much heterogeneity in outcomes with respect to deafness etiology subgroup analysis. Sound localization abilities tended to improve longitudinally in the entire cohort. Binaural benefits using an adaptive Hearing in Noise Test test showed a significant (P < 0.001) improvement with head shadow effect. Utilizing the Iowa Tinnitus Handicap Questionnaire, there was significant improvement in social, physical, and emotional well‐being (P = 0.011), along with hearing abilities (P = 0.001). Conclusions This case series is the largest cohort of CI SSD subjects to date and systematically analyzes their functional outcomes. Subjects have meaningful improvement in word understanding, and sound localization tends to gradually improve over time. Binaural benefit analysis showed significant improvement with head shadow effect, which likely provides ease of listening. Level of Evidence 4 Laryngoscope, 130:1805–1811, 2020

Speech Recognition as a Function of Age and Listening Experience in Adult Cochlear Implant Users

“…Performance tends to improve with early CI listening experience, but there are discrepancies in the literature about the time course of acclimatization. Some studies observe a plateau in speech recognition by 6 months of CI use 9,12 and others document continued improvement over several years 21–25 . Acclimatization with the CI may be influenced by age at implantation, with older adults needing more listening experience before reaching asymptotic performance as compared to younger adults due to age‐related effects on auditory processing.…”

“…Some studies observe a plateau in speech recognition by 6 months of CI use 9,12 and others document continued improvement over several years. [21][22][23][24][25] Acclimatization with the CI may be influenced by age at implantation, with older adults needing more listening experience before reaching asymptotic performance as compared to younger adults due to age-related effects on auditory processing. Data on effects of age for asymptotic performance are mixed, as some studies have shown poorer speech recognition for older adults, [26][27][28][29][30][31][32][33] while others indicate no age effect.…”

Insights into the Pathobiology of TMPRSS3-Related Hearing Loss and Implications for Cochlear Implant Patients with TMPRSS3 Mutations.

“…Eight large studies of more than 10 patients reported post-lingual adult CI outcomes for 565 individuals and these patients exhibited a mean (SD) post-operative CNC word score of 50.1% (12.5%). [26][27][28][29][30][31][32][33] These outcomes compare similarly to a large systematic review of adult CI outcomes of 2798 patients across 46 studies and showed CNC scores improved from 8.3% (12.4) to 54.0% (22.5) 34 . A one-way ANOVA was conducted to compare mean postoperative CNC WRS between the TMPRSS3 cohort and the eight adult hearing loss studies [66.2% (25.8) vs. 50.1% (12.5)].…”

“…40 Regardless of the four poor performers in this study, our post-operative CNC word scores remained comparable to CI outcomes of the general hearing loss population. [26][27][28][29][30][31][32][33] Interestingly, all poor performers carry the p.Ala138Glu mutation, but with different alleles in trans. The p.Ala138Glu variant occurs in the SRCR domain.…”

Effects of Cochlear Implantation on Tinnitus and Depression

“…Although sparse evidence has demonstrated that CI has "negative effects" on tinnitus [9,10], most studies in this regard have shown that CI is associated with a decrease in the intensity and discomfort caused by tinnitus [8,11]. In fact, in recent years, CI has been used in selected cases of unilateral deafness and asymmetric hearing loss with bothersome tinnitus, with excellent results [12][13][14]. Based on these findings, CI can be a valuable treatment method for patients with tinnitus.…”