Benefits of Cochlear Implantation for Single-Sided Deafness: Data From the House Clinic-University of Southern California-University of California, Los Angeles Clinical Trial

Cochlear implant usage in single sided deafness and factors affecting usage

OBJECTIVES

The primary objective was to examine duration of daily cochlear implant (CI) usage at 12 and 24 months post-operatively in single sided deafness (SSD). The secondary objective was to examine factors that could affect CI usage.

METHODS

Retrospective cohort of patients with SSD who received CI from January 2015 to March 2020. CI usage was evaluated at 12 and 24 months. Hearing loss duration, tinnitus scores and signal-to-noise ratio (SNR) were correlated with CI usage at 12 months.

RESULTS

Usage data was available for 54 patients at 12 months and 38 patients at 24 months. The mean usage was 8.2 h/day (SD 4.2) at 12 months, 7.0 h/day (SD 5.1) at 24 months. 5 out of 54 (9.3%) and 7 out of 38 patients (18.4%) were non-users at 12 and 24 months post-operatively. An improved mean SNR score from pre-operative 4.4 dB (SD 2.8) to - 0.70 dB (SD 4.2) at 12 months post-operative was positively correlated with CI usage at 12 and 24 months. Hearing loss duration and tinnitus scores were not associated with CI usage.

CONCLUSIONS

18.4% of our patients were non-users at 24 months. Mean usage at 24 months was 7.0 h/day. Improved hearing in noise at 12 months was correlated with better usage.

Speech Recognition and Subjective Hearing Abilities for Electric-Acoustic Stimulation Users With Unilateral Hearing Loss

OBJECTIVE

Some cochlear implant (CI) recipients with unilateral hearing loss (UHL) have functional acoustic hearing in the implanted ear, warranting the fitting of an ipsilateral electric-acoustic stimulation (EAS) device. The present study assessed speech recognition and subjective hearing abilities over time for EAS users with UHL.

STUDY DESIGN

Prospective, repeated-measures.

SETTING

Tertiary referral center.

PATIENTS

Adult CI recipients with normal-to-moderate low-frequency acoustic thresholds in the implanted ear and a contralateral pure-tone average (0.5, 1, and 2 kHz) ≤25 dB HL.

MAIN OUTCOME MEASURES

Participants were evaluated preoperatively and at 1, 3, and 6 months post-activation. Speech recognition for the affected ear was evaluated with CNC words in quiet. Masked speech recognition in the bilateral condition was evaluated with AzBio sentences in a 10-talker masker (0 dB SNR) for three spatial configurations: target from the front and masker either colocated with the target or presented 90 degrees toward the affected or contralateral ear. Responses to the Speech, Spatial, and Qualities of Hearing Scale subscales were used to assess subjective hearing abilities.

RESULTS

Participants experienced significant improvements in CNC scores ( F(3,13) = 14.90, p < 0.001), and masked speech recognition in the colocated ( F(3,11) = 3.79, p = 0.043) and masker toward the contralateral ear ( F(3,11) = 4.75, p = 0.023) configurations. They also reported significantly better abilities on the Speech Hearing ( F(3,13) = 5.19, p = 0.014) and Spatial Hearing ( F(3,13) = 10.22, p = 0.001) subscales.

CONCLUSIONS

Adults with UHL and functional acoustic hearing in the implanted ear experience significant improvements in speech recognition and subjective hearing abilities within the initial months of EAS use as compared with preoperative performance and perceptions.

The temporal mismatch across listening sides affects cortical auditory evoked responses in normal hearing listeners and cochlear implant users with contralateral acoustic hearing

Combining a cochlear implant with contralateral acoustic hearing typically enhances speech understanding, although this improvement varies among CI users and can lead to an interference effect. This variability may be associated with the effectiveness of the integration between electric and acoustic stimulation, which might be affected by the temporal mismatch between the two listening sides. Finding methods to compensate for the temporal mismatch might contribute to the optimal adjustment of bimodal devices and to improve hearing in CI users with contralateral acoustic hearing. The current study investigates cortical auditory evoked potentials (CAEPs) in normal hearing listeners (NH) and CI users with contralateral acoustic hearing. In NH, the amplitude of the N1 peak and the maximum phase locking value (PLV) were analyzed under monaural, binaural, and binaural temporally mismatched conditions. In CI users, CAEPs were measured when listening with CI only (CIS_only), acoustically only (AS_only) and with both sides together (CIS+AS). When listening with CIS+AS, various interaural delays were introduced between the electric and acoustic stimuli. In NH listeners, interaural temporal mismatch resulted in decreased N1 amplitude and PLV. Moreover, PLV is suggested as a more sensitive measure to investigate the integration of information between the two listening sides. CI users showed varied N1 latencies between the AS_only and CIS_only listening conditions, with increased N1 amplitude when the temporal mismatch was compensated. A tendency towards increased PLV was also observed, however, to a lesser extent than in NH listeners, suggesting a limited integration between electric and acoustic stimulation. This work highlights the potential of CAEPs measurement to investigate cortical processing of the information between two listening sides in NH and bimodal CI users.

A Consensus to Revise the Minimum Speech Test Battery-Version 3

PURPOSE

The Minimum Speech Test Battery (MSTB) for adults was introduced in 1996 (Nilsson et al., 1996) and subsequently updated in 2011 (Advanced-Bionics et al., 2011). The MSTB has been widely used by clinicians as a guide for cochlear implant (CI) candidacy evaluations and to document post-operative speech recognition performance. Due to changes in candidacy over the past 10 years, a revision to the MSTB was needed.

METHOD

In 2022, the Institute for Cochlear Implant Training (ICIT) recruited a panel of expert CI audiologists to update and revise the MSTB. This panel utilized a modified Delphi consensus process to revise the test battery and to improve its applicability considering recent changes in CI care.

RESULTS

This resulted in the MTSB-Version 3 (MSTB-3), which includes test protocols for identifying not only traditional CI candidates but also possible candidates for electric-acoustic stimulation and patients with single-sided deafness and asymmetric hearing loss. The MSTB-3 provides information that supplements the earlier versions of the MSTB, such as recommendations of when to refer patients for a CI, recommended patient-reported outcome measures, considerations regarding the use of cognitive screeners, and sample report templates for clinical documentation of pre- and post-operative care. Electronic versions of test stimuli, along with all the materials described above, will be available to clinicians via the ICIT website (https://www.cochlearimplanttraining.com).

CONCLUSION

The goal of the MSTB-3 is to be an evidence-based test battery that will facilitate a streamlined standard of care for adult CI candidates and recipients that will be widely used by CI clinicians.

Auditory Localization Performance in Cochlear Implant Recipients With Single-Sided Deafness: The Challenges and Limitations of Current Outcome Metrics

HYPOTHESIS

Acoustic localization accuracy metrics currently employed in clinical literature both overestimate and underestimate performance benefit of cochlear implantation (CI) for single-sided deafness (SSD).

BACKGROUND

Although localization in SSD with CI has been investigated, performance characterization has relied heavily on average error. Although attractively concise, this measure may misrepresent performance. Here, we characterize frequency-specific localization on a granular level in subjects with CI for SSD as a critical analysis of localization outcome metrics.

METHODS

Eight CI recipients with SSD were recruited. Stimuli of broadband (BBN) and narrowband noise (NBN) at low (500 Hz), mid (1000 Hz), and high (4000 Hz) frequencies were presented in a semianechoic chamber. Localization accuracy was quantified in mean angular error (MAE) and linear regression slope.

RESULTS

Use of a CI for SSD subjects improved localization performance by slope for all stimuli ( p ≤ 0.0033) to a level that was equal to normal-hearing controls at 1 and 4 kHz ( p ≥ 0.2281). MAE was also significantly improved for SSD subjects using CI for BBN stimuli ( p ≪ 0.0001); however, no statistically significant improvement in MAE was seen for NBN ( p ≥ 0.5773) with CI use. Descriptive analysis of individual subject performance highlights the reasons for contradictory results.

CONCLUSION

There is inherent challenge in characterizing localization benefit for individuals with CI for SSD. Our data demonstrate the limitations of utilization of average error as the sole metric for outcome benefit. We emphasize the importance of continued research investigating alternative outcome measures as we work toward a more refined understanding of the potential benefits and limitations of cochlear implantation for SSD.

Auditory Outcomes Following Cochlear Implantation in Children with Unilateral Hearing Loss

OBJECTIVE

Unilateral hearing loss (UHL) in children is associated with speech and language delays. Cochlear implantation (CI) is currently the only rehabilitative option that restores binaural hearing. This study aims to describe auditory outcomes in children who underwent CI for UHL and to determine the association between duration of hearing loss and auditory outcomes.

STUDY DESIGN

Retrospective case series.

SETTING

Three tertiary-level, academic institutions.

PATIENTS

Children <18 years with UHL who underwent CI between 2018 and 2021.

INTERVENTION

Cochlear implantation.

MAIN OUTCOME MEASURES

Speech perception and Speech, Spatial and Qualities of Hearing Scale (SSQ) were assessed postimplantation. Scores >50% on speech perception and SSQ scores >8 points were considered satisfactory. Associations between duration of UHL and implantation age and outcomes were assessed using Spearman's rank correlation.

RESULTS

Of the 38 children included, mean age at CI was 7.9 ± 3.2 years and mean UHL duration was 5.0 ± 2.8 years. Mean datalogging was 8.1 ± 3.1 hours/day. Mean auditory testing scores were SSQ, 7.9 ± 1.2; BABY BIO, 68.1 ± 30.2%; CNC, 38.4 ± 28.4%; WIPI, 52.5 ± 23.1%. Scores >50% on CNC testing were achieved by 40% of patients. SSQ scores >8 points were reported by 78% (7/9) of patients. There were no significant correlations between UHL duration and auditory outcomes.

CONCLUSION

Overall, children with UHL who undergo CI can achieve satisfactory speech perception scores and SSQ scores. There were no associations between duration of hearing loss and age at implantation with auditory outcomes. Multiple variables may impact auditory outcomes, including motivation, family support, access to technology, and consistent isolated auditory training postactivation and should be taken into consideration in addition to age at implantation and duration of UHL in determination of CI candidacy.

Prospective study of sound localisation in patients with single sided deafness and asymmetric hearing loss treated with cochlear implant

BACKGROUND AND OBJECTIVE

Sound localization plays a crucial role in our daily lives, enabling us to recognize voices, respond to alarming situations, avoid dangers, and navigate towards specific signals. However, this ability is compromised in patients with Single-Sided Deafness (SSD) and Asymmetric Hearing Loss (AHL), negatively impacting their daily functioning. The main objective of the study was to quantify the degree of sound source localization in patients with single-sided deafness or asymmetric hearing loss using a Cochlear Implant (CI) and to compare between the two subgroups.

MATERIALS AND METHODS

This was a prospective, longitudinal, observational, single-center study involving adult patients diagnosed with profound unilateral or asymmetric sensorineural hearing loss who underwent cochlear implantation. Sound localization was assessed in a chamber equipped with seven speakers evenly distributed from -90º to 90º. Stimuli were presented at 1000 Hz and intensities of 65 dB, 70 dB, and 75 dB. Each stimulus was presented only once per speaker, totaling 21 presentations. The number of correct responses at different intensities was recorded, and angular error in degrees was calculated to determine the mean angular distance between the patient-indicated speaker and the speaker presenting the stimulus. Both assessments were conducted preoperatively without a cochlear implant and two years post-implantation.

RESULTS

The total sample comprised 20 patients, with 9 assigned to the SSD group and 11 to the AHL group. The Preoperative Pure Tone Average (PTA) in free field was 31.7 dB in the SSD group and 41.8 dB in the AHL group. There was a statistically significant improvement in sound localization ability and angular error with the use of the cochlear implant at all intensities in both SSD and AHL subgroups.

CONCLUSIONS

Cochlear implantation in patients with SSD and AHL enhances sound localization, reducing mean angular error and increasing the number of correct sound localization responses.

Clinical experience with the Nurotron™ cochlear implant in a Spanish-speaking postlingual population: Clinical safety and audiological results

OBJECTIVE

to assess clinical safety and postoperative audiological outcomes in postlingual deafness Spanish speaking patients, who underwent surgery with Nurotron™ cochlear implant.

MATERIAL AND METHODS

Retrospective descriptive case series study. We performed follow-up of complications and audiological measurements before and after cochlear implantation. Patients with bilateral severe to profound sensorineural hearing loss or patients with unilateral deafness with/without tinnitus were included. Repeated-measures within-subjects for assess pure tone thresholds and speech performance (bilingual test) with a detailed monitoring to establish security or adverse effects were performed. Analysis of variance tests, repetitive measures, were used for statistical analysis.

RESULTS

31 patients were included, 17 (54.8%) men and 14 (45.2%) women. Mean age at the time of surgery was 49.82 ± 18.8 years. The mean follow-up of the group was 31.56 ± 9.57 months (minimum = 19.6 months and maximum = 52.50 months). As major complication one patient (3.23%) had a hard failure that required removal and re-implantation. 25.8% of the patients presented minor complications, the most frequent being vertigo/unsteadiness in 22.6%. The mean of language discrimination (free field at 65 dB SPL) was 62.19% ± 16.66; being 69.82% ± 7.35 in the group of severe to profound bilateral sensorineural hearing loss. A statistically significant reduction was observed in patients with tinnitus, assessed using the visual analogue scale, preoperative = 7.2 ± 1,6 vs postoperative (18months postoperative) = 1.7 ± 1.3 (p < .001).

CONCLUSIONS

The Nurotron™ cochlear implant shows satisfactory audiological results, in accordance with what has been reported in the literature. Minor complications were similar to previous studies, but the percentage of hard failure should continue to be observed, which was higher than other reports with comparable follow-up.

The Chronological Evolution of Cochlear Implant Contraindications: A Comprehensive Review

Cochlear implantation has emerged as a transformative intervention in addressing profound hearing loss, offering a paradigm shift in auditory rehabilitation for individuals with restricted auditory function. Throughout its history, the understanding of contraindications for cochlear implant (CI) surgery has evolved significantly. This review comprehensively analyzes the chronological advancements in the understanding of CI contraindications, examining studies conducted from historical timelines to the present. Recent research has revealed significant developments in the field, prompting a reevaluation of established criteria and resulting in expanded indications for CI. The chronological evolution of contraindications underscores the transformative nature of the field, offering potential improvements in outcomes and enhancing the quality of life for individuals with profound hearing loss. In conclusion, this narrative review emphasizes the dynamic nature of the field, where the reevaluation of contraindications has created new opportunities and broader indications for CI. The emerging prospects, including improved outcomes and enhanced quality of life, hold promise for individuals with profound hearing loss.

Objective and subjective efficacy of hearing aids in patients with mild-to-moderate unilateral hearing loss: a prospective study

PURPOSE

In patients with unilateral sensorineural hearing loss (USNHL), we explored both objective functional audiological gains and subjective satisfaction, indicating when a unilateral hearing aid is valuable.

METHODS

Thirty-seven patients with mild-to-moderate USNHL (mean pure-tone thresholds between 25 and 70 dB) were prescribed unilateral hearing aids. Functional gain, the aided speech discrimination score (SDS), the Hearing in Noise Test (HINT) score, and the sound localization test score were collected, and a questionnaire (the Hearing Handicap Inventory for the Elderly, HHIE) completed after 1, 2, and 3 months of hearing aid use. We classified the participants as having 'no handicap' (HHIE < 17), 'mild-to-moderate handicap' (17-42), and 'significant handicap' (> 42).

RESULTS

The decrease in handicap afforded by unilateral hearing aids was largest in the 'significant handicap' group (the HHIE total score fell from 59.1 to 37.2; P = 0.007). There were no between-group differences in either functional gain or the aided SDS. Only the 'significant handicap' group evidenced an improved HINT score; the composite signal-to-noise ratio (SNR) fell from - 1.5 to - 2.2 dB [S/N] (P = 0.023). The HHIE usefully indicated when a hearing aid alleviated the discomfort of USNHL; patients with unaided HHIE scores ≥ 20 evidenced significant decreases in the composite SNR (- 1.7 to - 2.0 dB [S/N]; P = 0.045).

CONCLUSIONS

When considering whether to prescribe a unilateral hearing aid for patients with mild-to-moderate USNHL, it is helpful to use the HHIE to evaluate discomfort. If the total score is ≥ 20, a hearing aid is appropriate.

Masked Speech Perception with Bone Conduction Device, Contralateral Routing of Signals Hearing Aid, and Cochlear Implant Use in Adults with Single-Sided Deafness: A Prospective Hearing Device Comparison using a Unified Testing Framework

INTRODUCTION

For the treatment of single-sided deafness (SSD), common treatment choices include a contralateral routing of signals (CROS) hearing aid, a bone conduction device (BCD), and a cochlear implant (CI). The primary aim of this study was to compare speech understanding in noise and binaural benefits in adults with postlingual SSD between preoperative unaided baseline, preoperative CROS and BCD trial devices, and CI, following recommendations from a consensus protocol. In addition, we investigated the effect of masker type on speech understanding.

METHODS

This was a prospective study with twelve participants. Binaural effects of head shadow, squelch, summation, and spatial release from masking were assessed by measuring speech reception thresholds (SRTs) in five different spatial target-masker configurations using two different maskers: two-talker babble (TTB), and speech-shaped noise (SSN). Preoperatively, participants were assessed unaided and with CROS and BCD trial devices. After cochlear implantation, participants were assessed at 1, 3, and 6 months post-activation.

RESULTS

For TTB, significant improvements in SRT with a CI relative to preoperatively unaided were found in all spatial configurations. With CI at 6 months, median benefits were 7.8 dB in SSSDNAH and 5.1 dB in S0NAH (head shadow), 3.4 dB in S0N0 (summation), and 4.6 dB in S0NSSD and 5.1 dB in SAHNSSD (squelch). CROS yielded a significant head shadow benefit of 2.4 dB in SSSDNAH and a significant deterioration in squelch of 2.5 dB in S0NSSD and SAHNSSD, but no summation effect. With BCD, there was a significant summation benefit of 1.5 dB, but no head shadow nor squelch effect. For SSN, significant improvements in SRT with CI compared to preoperatively unaided were found in three spatial configurations. Median benefits with CI at 6 months were: 8.5 dB in SSSDNAH and 4.6 dB in S0NAH (head shadow), 1.4 dB in S0N0 (summation), but no squelch. CROS showed a significant head shadow benefit of 1.7 dB in SSSDNAH, but no summation effect, and a significant deterioration in squelch of 2.9 dB in S0NSSD and 3.2 dB in SAHNSSD. With BCD, no binaural effect was obtained. Longitudinally, we found significant head shadow benefits with a CI in SSSDNAH in both maskers at all postoperative intervals and in S0NAH at 3 and 6 months post-activation.

CONCLUSION

With a CI, a clear benefit for masked speech perception was observed for all binaural effects. Benefits with CROS and BCD were more limited. CROS usage was detrimental to the squelch effect.

American Cochlear Implant Alliance Task Force: Recommendations for Determining Cochlear Implant Candidacy in Adults

The indications for cochlear implantation have expanded over time due to evidence demonstrating identification and implantation of appropriate cochlear implant (CI) candidates lead to significant improvements in speech recognition and quality of life (QoL). However, clinical practice is variable, with some providers using outdated criteria and others exceeding current labeled indications. As a results, only a fraction of those persons who could benefit from CI technology receive it. This document summarizes the current evidence for determining appropriate referrals for adults with bilateral hearing loss into CI centers for formal evaluation by stressing the importance of treating each ear individually and a "revised 60/60 rule". By mirroring contemporary clinical practice and available evidence, these recommendations will also provide a standardized testing protocol for CI candidates using a team-based approach that prioritizes individualized patient care. This manuscript was developed by the Adult Cochlear Implantation Candidacy Task Force of the American Cochlear Implant Alliance using review of the existing literature and clinical consensus. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:S1-S14, 2024.

Matching the pitch perception of the cochlear implanted ear with the contralateral ear in patients with single-sided deafness: a novel approach

PURPOSE

Single-sided deaf patients following cochlear implantation often compare the sound quality of their implanted ear with normal hearing. The interaural differences can result in dissatisfaction with speech comprehension and reduced time of usage of the speech processor; hence, prolonging auditory adaptation time. The proposed calibration method presented in this study demonstrates how the frequency distribution of the cochlear implant can be set to adequately approximate the pitch perception of the contralateral normal hearing ear towards improving speech intelligibility in a noisy environment.

METHODS

In 12 postlingual single-sided deaf patients, subjective interaural pitch-matching was carried out to determine new central frequencies for the reallocation of the frequency bands of their speech processor (CP910, CP950 or CP1000, Cochlear, Australia). The patients were asked to compare the pitch of the tones presented to their normal hearing ear to the pitch of individual channels of their cochlear implant (CI522 or CI622, Cochlear, Australia). A third-degree polynomial curve was fit to the acquired matching frequencies to create the new frequency allocation table. Audiological measurements (free-field aided thresholds, speech reception thresholds, and monosyllabic word recognition score) in noise, together with a Speech, Spatial and Qualities of Hearing Scale (SSQ12) questionnaire (short version of the original SSQ) results were evaluated prior to the pitch-matching procedure, and again, 2 weeks later.

RESULTS

The free-field aided thresholds of the patients showed no greater shift than ± 5 dB following the procedure; however, their monosyllabic word recognition score in noise improved significantly (mean - 9.58%, SD 4.98%, matched pairs t test comparison: p < 0.001). The results of the SSQ12 questionnaire also showed significant improvement in speech intelligibility, sound localization, and sound quality (mean 0.96 points, SD 0.45 points, matched pairs t test comparison: p < 0.001).

CONCLUSIONS

Matching the pitch perception of the implanted cochlea with the sensation of the normal hearing contralateral ear, resulted in significant changes in the quality of hearing in patients with single-sided deafness. It is plausible the procedure can usher positive results in bimodal patients or following sequential bilateral cochlear implantation.

QoL, CIs, QALYs, and Individualized Rehabilitation: The Clinical and Practical Benefits of Regularly Assessing the Quality of Life of Adult Cochlear Implant Recipients

This study aimed to report quality of life (QoL) scores in unilateral cochlear implant (CI) users and to generate guidance for clinicians on using QoL measures to individualize CI counselling and rehabilitation and to increase access to CIs as a mode of rehabilitation. Participants (n = 101) were unilateral CI users with single-sided deafness (SSD; n = 17), asymmetrical hearing loss (AHL; n = 26), or bilateral hearing loss (Uni; n = 58). Generic QoL was assessed via the Health Utilities Index (HUI-3), and disease-specific QoL was assessed via the Speech, Spatial, and Qualities of Hearing scale (SSQ12) and Nijmegen CI Questionnaire (NCIQ) at preimplantation and at 6 and 12 months of CI use. All groups had significantly increased HUI-3 scores at both intervals. The SSD group showed significant benefit on the SSQ12 at visit 3, the AHL group showed significant benefit on the SSQ12 and most NCIQ subdomains at both intervals, and the Uni group showed significant benefit with both tests at both intervals. Unilateral CI recipients demonstrate improved QoL within the first 12 months of device use. Regular assessment with generic and disease-specific questionnaires has the potential to play an important role in personalizing treatment and possibly in increasing access to CI provision.

Cochlear implantation in unilateral hearing loss: impact of short- to medium-term auditory deprivation

Introduction

Single sided deafness (SSD) results in profound cortical reorganization that presents clinically with a significant impact on sound localization and speech comprehension. Cochlear implantation (CI) has been approved for two manufacturers' devices in the United States to restore bilateral function in SSD patients with up to 10 years of auditory deprivation. However, there is great variability in auditory performance and it remains unclear how auditory deprivation affects CI benefits within this 10-year window. This prospective study explores how measured auditory performance relates to real-world experience and device use in a cohort of SSD-CI subjects who have between 0 and 10 years of auditory deprivation.

Methods

Subjects were assessed before implantation and 3-, 6-, and 12-months post-CI activation via Consonant-Nucleus-Consonant (CNC) word recognition and Arizona Biomedical Institute (AzBio) sentence recognition in varying spatial speech and noise presentations that simulate head shadow, squelch, and summation effects (S0N0, SSSDNNH, SNHNSSD; 0 = front, SSD = impacted ear, NH = normal hearing ear). Patient-centered assessments were performed using Tinnitus Handicap Inventory (THI), Spatial Hearing Questionnaire (SHQ), and Health Utility Index Mark 3 (HUI3). Device use data was acquired from manufacturer software. Further subgroup analysis was performed on data stratified by <5 years and 5-10 years duration of deafness.

Results

In the SSD ear, median (IQR) CNC word scores pre-implant and at 3-, 6-, and 12-months post-implant were 0% (0-0%), 24% (8-44%), 28% (4-44%), and 18% (7-33%), respectively. At 6 months post-activation, AzBio scores in S0N0 and SSSDNNH configurations (n = 25) demonstrated statistically significant increases in performance by 5% (p = 0.03) and 20% (p = 0.005), respectively. The median HUI3 score was 0.56 pre-implant, lower than scores for common conditions such as anxiety (0.68) and diabetes (0.77), and comparable to stroke (0.58). Scores improved to 0.83 (0.71-0.91) by 3  months post-activation. These audiologic and subjective benefits were observed even in patients with longer durations of deafness.

Discussion

By merging CI-associated changes in objective and patient-centered measures of auditory function, our findings implicate central mechanisms of auditory compensation and adaptation critical in auditory performance after SSD-CI and quantify the extent to which they affect the real-world experience reported by individuals.

Cochlear Implants for Single-Sided Deafness: Quality of Life, Daily Usage, and Duration of Deafness

OBJECTIVE

To report our experience for adults undergoing cochlear implantation (CI) for single-sided deafness (SSD).

METHODS

This is a retrospective case series for adults with SSD who underwent CI between January 2013 and May 2021 at our institution. CNC and AzBio speech recognition scores, Tinnitus Handicap Inventory (THI), Speech, Spatial, and Qualities of Hearing Scale (SSQ12), datalogging, and the Cochlear Implant Quality of Life (CIQOL)-10 Global measure were utilized.

RESULTS

Sixty-six adults underwent CI for SSD (median 51.3 years, range 20.0-74.3 years), and 57 (86.4%) remained device users at last follow-up. Compared to pre-operative performance, device users demonstrated significant improvement in speech recognition scores and achieved peak performance at six months post-activation for CNC (8.0% increased to 45.6%, p < 0.0001) and AzBio in quiet (12.2% increased to 59.5%, p < 0.0001). THI was decreased at 6 months post-implantation (58.1-14.6, p < 0.0001), with 77% of patients reporting improved or resolved tinnitus. Patients demonstrated improved SSQ12 scores as well as the disease-specific CIQOL-10 Global questionnaire. Duration of deafness was not associated with significant differences in speech recognition performance. Average daily wear time was positively associated with CNC and AzBio scores as well as post-operative CIQOL-10 scores.

CONCLUSIONS

Herein we present the largest cohort of adult CI recipients with SSD with data on speech recognition scores, tinnitus measures, and SSQ12. Novel insights regarding the correlation of datalogging, duration of deafness, and CI-specific quality of life (CIQOL-10) metrics are discussed. Data continue to support CI as an efficacious treatment option for SSD.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2362-2370, 2023.

Long-Term Binaural Hearing Improvements for Cochlear Implant Users with Asymmetric Hearing Loss

OBJECTIVE

To assess long-term binaural hearing abilities for cochlear implant (CI) users with unilateral hearing loss (UHL) or asymmetric hearing loss (AHL).

METHODS

A prospective, longitudinal, repeated measures study was completed at a tertiary referral center evaluating adults with UHL or AHL undergoing cochlear implantation. Binaural hearing abilities were assessed with masked speech recognition tasks using AzBio sentences in a 10-talker masker. Performance was evaluated as the ability to benefit from spatial release from masking (SRM). SRM was calculated as the difference in scores when the masker was presented toward the CI-ear (SRMci ) or the contralateral ear (SRMcontra ) relative to the co-located condition (0°). Assessments were completed pre-operatively and at annual intervals out to 5 years post-activation.

RESULTS

Twenty UHL and 19 AHL participants were included in the study. Linear Mixed Models showed significant main effects of interval and group for SRMcontra . There was a significant interaction between interval and group, with UHL participants reaching asymptotic performance early and AHL participants demonstrating continued growth in binaural abilities to 5 years post-activation. The improvement in SRM showed a significant positive correlation with contralateral unaided hearing thresholds (p = 0.050) as well as age at implantation (p = 0.031).

CONCLUSIONS

CI recipients with UHL and AHL showed improved SRM with long-term device use. The time course of improvement varied by cohort, with the UHL cohort reaching asymptotic performance early and the AHL cohort continuing to improve beyond 1 year. Differences between cohorts could be driven by differences in age at implantation as well as contralateral unaided hearing thresholds.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1480-1485, 2023.

Cochlear Implantation in Sporadic Vestibular Schwannoma and Neurofibromatosis Type II

Cochlear implantation offers significantly better hearing outcomes than auditory brainstem implantation in patients with vestibular schwannoma. Neither the primary treatment modality nor the cause of the tumor (neurofibromatosis type 2 related or sporadic) seems to have a significant effect on hearing outcome with cochlear implantation. Some uncertainty remains regarding long-term hearing outcomes; however, cochlear implantation in vestibular schwannoma serves to offer patients, with a functioning cochlear nerve, the probability of open set speech discrimination with a consequent positive impact on quality of life.

Cochlear Implantation Outcomes in Adults With Single-Sided Deafness: A Systematic Review and Meta-analysis

OBJECTIVE

To assess spatial hearing, tinnitus, and quality-of-life outcomes in adults with single-sided deafness (SSD) who underwent cochlear implantation.

DATABASES REVIEWED

PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from January 2008 to September 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

Studies reporting spatial hearing, tinnitus, and quality-of-life outcomes in adult cochlear implant (CI) recipients (≥18 yr old) with SSD were evaluated. Study characteristics, demographic data, spatial hearing (speech recognition in noise, sound source localization), tinnitus (severity, loudness), and quality-of-life outcomes were collected.

RESULTS

From an initial search of 1,147 articles, 36 studies that evaluated CI use in 796 unique adults with SSD (51.3 ± 12.4 yr of age at time of implantation) were included. The mean duration of deafness was 6.2 ± 9.6 years. There was evidence of improvement for speech recognition in noise using different target-to-masker spatial configurations, with the largest benefit observed for target-to-masker configurations assessing head shadow (mean, 1.87-6.2 dB signal-to-noise ratio). Sound source localization, quantified as root-mean-squared error, improved with CI use (mean difference [MD], -25.3 degrees; 95% confidence interval [95% CI], -35.9 to -14.6 degrees; p < 0.001). Also, CI users reported a significant reduction in tinnitus severity as measured with the Tinnitus Handicap Inventory (MD, -29.97; 95% CI, -43.9 to -16.1; p < 0.001) and an improvement in spatial hearing abilities as measured with the Spatial, Speech, and Qualities of Hearing questionnaire (MD, 2.3; 95% CI, 1.7 to 2.8; p < 0.001).

CONCLUSIONS

Cochlear implantation and CI use consistently offer improvements in speech recognition in noise, sound source localization, tinnitus, and perceived quality of life in adults with SSD.

Improving Auditory Perception in Pediatric Single-Sided Deafness: Use of Cochlear Implants' Direct Connection for Remote Speech Perception Rehabilitation

PURPOSE

Unilateral cochlear implants (CIs) can restore binaural hearing in single-sided deafness (SSD). Direct stimulation of the CI can be obtained via the Bluetooth connection of a device to the CI, thus excluding the typical-hearing ear. This study aims to investigate the use of CI connectivity features as a rehabilitative strategy in a small cohort of children affected by SSD.

METHOD

A newly developed training protocol was presented to children with SSD who have less than 2 years of experience with CI. We developed a user-friendly and short-term (six sessions within 20 days) training protocol for speech perception that patients themselves can manage independently at home using CI connectivity systems. Children were telematically tested before and after the training by trained speech and language therapists.

RESULTS

Four patients met the inclusion criteria. They all showed better results in the final online assessment, when compared with the initial one.

CONCLUSIONS

To our knowledge, this is the first clinical focus article presenting an auditory training protocol for SSD patients with CI using the Bluetooth connectivity systems for teletherapy. The results, although preliminary, support the efficacy of this rehabilitative strategy. Further research is needed to support our findings.

Health State Utility Values Associated with Cochlear Implants in Adults: A Systematic Review and Network Meta-Analysis

OBJECTIVES

The cost-effectiveness of bilateral cochlear implants in adults remains uncertain despite established clinical benefits. In cost-effectiveness studies, benefit is often measured by change in health state utility value (HSUV), a single number summary of health-related quality of life anchored at 0 (state of being dead) and 1 (perfect health). Small differences in bilateral cochlear implant HSUV change conclusions of published models, and invalid estimates can therefore mislead policy and funding decisions. As such, we aimed to review and synthesize published HSUV estimates associated with cochlear implants.

DESIGN

We included observational or experimental studies reporting HSUV for adult patients (age ≥18 years) with at least moderate-profound sensorineural hearing loss in both ears who received unilateral or bilateral cochlear implants. We searched MEDLINE, EMBASE, PsycINFO, and Cochrane Library databases up to May 1, 2021. Study and participant characteristics and HSUV outcomes were extracted. Narrative synthesis is reported for all studies. A Bayesian network meta-analysis was conducted to generate pooled estimates for the mean difference in HSUV for three comparisons: (1) unilateral cochlear implant versus preimplant, (2) bilateral cochlear implants versus preimplant, (3) bilateral versus unilateral cochlear implants. Our principal measure was pooled mean difference in HSUV.

RESULTS

Thirty-six studies reporting unique patient cohorts were identified. Health Utilities Index, 3 (HUI-3) was the most common HSUV elicitation method. HSUV from 19 preimplant mean estimates (1402 patients), 19 unilateral cochlear implant mean estimates (1701 patients), and 5 bilateral cochlear implants mean estimates (83 patients) were pooled to estimate mean differences in HUI-3 HSUV by network meta-analysis. Compared with preimplant, a unilateral cochlear implant was associated with a mean change in HSUV of +0.17 (95% credible interval [CrI] +0.12 to +0.23) and bilateral cochlear implants were associated with a mean change of +0.25 (95% CrI +0.12 to +0.37). No significant difference in HSUV was detected for bilateral compared with unilateral cochlear implants (+0.08 [95% CrI -0.06 to +0.21]). Overall study quality was moderate.

CONCLUSIONS

The findings of this review and network meta-analysis comprise the best-available resource for parameterization of cost-utility models of cochlear implantation in adults and highlight the need to critically evaluate the validity of available HSUV instruments for bilateral cochlear implant populations.Protocol registration: PROSPERO (CRD42018091838).

Quality of Life Impact of Cochlear Implantation for Single-Sided Deafness: Assessing the Interrelationship of Objective and Subjective Measures

OBJECTIVE

To determine the effect on quality of life (QOL) of cochlear implantation (CI) for single-sided deafness (SSD) and asymmetric hearing loss (AHL) using the first psychometrically developed CI-specific QOL tool for English-speaking patients and to assess its relationship to objective perceptual measures.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary-care medical center.

PATIENTS

English-speaking adults with SSD or AHL.

INTERVENTIONS

Unilateral CI.

MAIN OUTCOME MEASURES

Cochlear Implant Quality of Life (CIQOL) score, CI-alone speech-in-quiet (SIQ) score (CNC and AzBio), binaural speech-in-noise (SIN) threshold, binaural azimuthal sound localization (SL) error.

RESULTS

At the most recent postoperative evaluation (median, 9.3 months postimplantation), 25 of 28 subjects (89%) had a CIQOL improvement, with the improvement considered clinically beneficial (>3 points) for 18 of 28 subjects (64%). Group-mean CIQOL improvement was observed at the first postoperative visit and did not change significantly thereafter. Objective perceptual measures (SL, SIQ, SIN) continued to improve over 12 months after implantation. Linear mixed-model regression analyses showed a moderate positive correlation between SIN and SIQ improvements (r = 0.50 to 0.59, p < 0.0001) and a strong positive correlation between the improvement in the two SIQ measures (r = 0.89, p < 0.0001). No significant relationships were observed ( p > 0.05) among QOL or the objective perceptual measures.

CONCLUSIONS

QOL improved for the majority of subjects implanted for SSD and AHL. Different time courses for improvement in QOL and audiologic tests, combined with the lack of significant relationships among them, suggest that QOL outcomes reflect different aspects of the CI experience than those captured by speech-understanding and localization measures. SIQ may substitute for SIN when clinical constraints exist.

Auditory cortical plasticity after cochlear implantation in asymmetric hearing loss is related to spatial hearing: a PET H215O study

In asymmetric hearing loss (AHL), the normal pattern of contralateral hemispheric dominance for monaural stimulation is modified, with a shift towards the hemisphere ipsilateral to the better ear. The extent of this shift has been shown to relate to sound localization deficits. In this study, we examined whether cochlear implantation to treat postlingual AHL can restore the normal functional pattern of auditory cortical activity and whether this relates to improved sound localization. The auditory cortical activity was found to be lower in the AHL cochlear implanted (AHL-CI) participants. A cortical asymmetry index was calculated and showed that a normal contralateral dominance was restored in the AHL-CI patients for the nonimplanted ear, but not for the ear with the cochlear implant. It was found that the contralateral dominance for the nonimplanted ear strongly correlated with sound localization performance (rho = 0.8, P < 0.05). We conclude that the reorganization of binaural mechanisms in AHL-CI subjects reverses the abnormal lateralization pattern induced by the deafness, and that this leads to improved spatial hearing. Our results suggest that cochlear implantation enables the reconstruction of the cortical mechanisms of spatial selectivity needed for sound localization.

Cochlear Implantation in Adults With Single-Sided Deafness: A Systematic Review and Meta-analysis

OBJECTIVE

To determine the clinical outcomes of adult patients with single-sided deafness (SSD) undergoing ipsilateral cochlear implantation.

DATA SOURCE

An electronic search of Medline and Embase articles.

REVIEW METHODS

A systematic review was performed with a search strategy developed by a licensed librarian to identify studies of adult patients with SSD who underwent ipsilateral cochlear implantation. Articles were managed in Covidence and evaluated by 2 independent reviewers. Risk of bias was assessed and data were extracted, including patient demographics, etiology of deafness, duration of deafness, and postoperative change in speech recognition, tinnitus, sound localization, and quality of life (QoL). A meta-analysis was performed, and pooled mean differences were calculated for each outcome of interest via random effects models by each outcome, as well as subgroup analyses by the individual clinical score used.

RESULTS

Of 2309 studies identified, 185 full texts were evaluated, and 50 were ultimately included involving 674 patients. Speech perception scores in quiet and noise, tinnitus control, sound localization, and QoL all significantly improved after implantation. Pooled outcomes demonstrated score improvements in speech perception (standardized mean difference [SMD], 2.8 [95% CI, 2.16-3.43]), QoL (SMD, 0.68 [95% CI, 0.45-0.91]), sound localization (SMD, -1.13 [95% CI, -1.68 to -0.57]), and tinnitus score reduction (SMD, -1.32 [95% CI, -1.85 to -0.80]).

CONCLUSIONS

Cochlear implantation in adults with SSD results in significant improvements in speech perception, tinnitus control, sound localization, and QoL.

LEVEL OF EVIDENCE: 2

Twelve-Month Outcomes of Simultaneous Translabyrinthine Resection and Cochlear Implantation

OBJECTIVE

Audiometric outcomes at 12 months following simultaneous translabyrinthine (TL) resection of vestibular schwannoma (VS) and cochlear implantation (CI).

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

METHODS

Adult patients undergoing TL resection of sporadic, unilateral VS ≤ 2 cm were prospectively enrolled. Preoperative testing included binaural AZBio in noise and quiet and unilateral Consonant-Nucleus-Consonant (CNC). Tinnitus Handicap Index (THI) and Speech, Spatial, and Qualities of Hearing (SSQ) questionnaires were also completed. Patients underwent TL resection with simultaneous CI. The preoperative test battery was repeated at 1, 3, 6, and 12 months after activation. Statistical analysis was performed to characterize short-term outcomes (preoperative to 3 months), longer-term outcomes (3-12 months), and overall changes during the preoperative to 12-month period.

RESULTS

AZBio, CNC, and THI improved at 3 months with no significant changes thereafter and showed durable improvement at 12 months compared to preoperative testing. While SSQ did not improve at 12 months, a subset of patients showed either recovery or improvement of SSQ-spatial subscores. Patients with cerebellopontine angle tumors had poorer performance, although the impact of tumor size and location could not be deduced based on the small sample size.

CONCLUSION

Patients undergoing simultaneous CI and TL resection of VS had durable improvements in speech perception and tinnitus severity 12 months following surgery. Subjective improvements in localization were not observed. Additional studies are needed to determine which VS patients are optimal candidates for CI.

Selective attention decoding in bimodal cochlear implant users

The growing group of cochlear implant (CI) users includes subjects with preserved acoustic hearing on the opposite side to the CI. The use of both listening sides results in improved speech perception in comparison to listening with one side alone. However, large variability in the measured benefit is observed. It is possible that this variability is associated with the integration of speech across electric and acoustic stimulation modalities. However, there is a lack of established methods to assess speech integration between electric and acoustic stimulation and consequently to adequately program the devices. Moreover, existing methods do not provide information about the underlying physiological mechanisms of this integration or are based on simple stimuli that are difficult to relate to speech integration. Electroencephalography (EEG) to continuous speech is promising as an objective measure of speech perception, however, its application in CIs is challenging because it is influenced by the electrical artifact introduced by these devices. For this reason, the main goal of this work is to investigate a possible electrophysiological measure of speech integration between electric and acoustic stimulation in bimodal CI users. For this purpose, a selective attention decoding paradigm has been designed and validated in bimodal CI users. The current study included behavioral and electrophysiological measures. The behavioral measure consisted of a speech understanding test, where subjects repeated words to a target speaker in the presence of a competing voice listening with the CI side (CIS) only, with the acoustic side (AS) only or with both listening sides (CIS+AS). Electrophysiological measures included cortical auditory evoked potentials (CAEPs) and selective attention decoding through EEG. CAEPs were recorded to broadband stimuli to confirm the feasibility to record cortical responses with CIS only, AS only, and CIS+AS listening modes. In the selective attention decoding paradigm a co-located target and a competing speech stream were presented to the subjects using the three listening modes (CIS only, AS only, and CIS+AS). The main hypothesis of the current study is that selective attention can be decoded in CI users despite the presence of CI electrical artifact. If selective attention decoding improves combining electric and acoustic stimulation with respect to electric stimulation alone, the hypothesis can be confirmed. No significant difference in behavioral speech understanding performance when listening with CIS+AS and AS only was found, mainly due to the ceiling effect observed with these two listening modes. The main finding of the current study is the possibility to decode selective attention in CI users even if continuous artifact is present. Moreover, an amplitude reduction of the forward transfer response function (TRF) of selective attention decoding was observed when listening with CIS+AS compared to AS only. Further studies to validate selective attention decoding as an electrophysiological measure of electric acoustic speech integration are required.

A Study of Event-Related Potentials During Monaural and Bilateral Hearing in Single-Sided Deaf Cochlear Implant Users

OBJECTIVES

Single-sided deafness (SSD) is characterized by a profoundly deaf ear and normal hearing in the contralateral ear. A cochlear implant (CI) is the only method to restore functional hearing in a profoundly deaf ear. In a previous study, we identified that the cortical processing of a CI signal differs from the normal-hearing ear (NHE) when directly compared using an auditory oddball paradigm consisting of pure tones. However, exactly how the brain integrates the electrical and acoustic signal is not well investigated. This study aims to understand how the provision of the CI in combination with the NHE may improve SSD CI users' ability to discriminate and evaluate auditory stimuli.

DESIGN

Electroencephalography from 10 SSD-CI participants (4 participated in the previous pure-tone study) were recorded during a semantic acoustic oddball task, where they were required to discriminate between odd and even numbers. Stimuli were presented in four hearing conditions: directly through the CI, directly to the NHE, or in free field with the CI switched on and off. We examined task-performance (response time and accuracy) and measured N1, P2, N2N4, and P3b event-related brain potentials (ERPs) linked to the detection, discrimination, and evaluation of task relevant stimuli. Sound localization and speech in noise comprehension was also examined.

RESULTS

In direct presentation, task performance was superior during NHE compared with CI (shorter and less varied reaction times [~720 versus ~842 msec], higher target accuracy [~93 versus ~70%]) and early neural responses (N1 and P2) were enhanced for NHE suggesting greater signal saliency. However, the size of N2N4 and P3b target-standard effects did not differ significantly between NHE and CI. In free field, target accuracy was similarly high with the CI (FF-On) and without the CI (FF-Off) (~95%), with some evidence of CI interference during FF-On (more variable and slightly but significantly delayed reaction times [~737 versus ~709 msec]). Early neural responses and late effects were also greater during FF-On. Performance on sound localization and speech in noise comprehension (S CI N NHE configuration only) was significantly greater during FF-On.

CONCLUSIONS

Both behavioral and neural responses in the semantic oddball task were sensitive to CI in both direct and free-field presentations. Direct conditions revealed that participants could perform the task with the CI alone, although performance was suboptimal and early neural responses were reduced when compared with the NHE. For free-field, the addition of the CI was associated with enhanced early and late neural responses, but this did not result in improved task performance. Enhanced neural responses show that the additional input from the CI is modulating relevant perceptual and cognitive processes, but the benefit of binaural hearing on behavior may not be realized in simple oddball tasks which can be adequately performed with the NHE. Future studies interested in binaural hearing should examine performance under noisy conditions and/or use spatial cues to allow headroom for the measurement of binaural benefit.

Cochlear Implant Facilitates the Use of Talker Sex and Spatial Cues to Segregate Competing Speech in Unilaterally Deaf Listeners

OBJECTIVES

Talker sex and spatial cues can facilitate segregation of competing speech. However, the spectrotemporal degradation associated with cochlear implants (CIs) can limit the benefit of talker sex and spatial cues. Acoustic hearing in the nonimplanted ear can improve access to talker sex cues in CI users. However, it's unclear whether the CI can improve segregation of competing speech when maskers are symmetrically placed around the target (i.e., when spatial cues are available), compared with acoustic hearing alone. The aim of this study was to investigate whether a CI can improve segregation of competing speech by individuals with unilateral hearing loss.

DESIGN

Speech recognition thresholds (SRTs) for competing speech were measured in 16 normal-hearing (NH) adults and 16 unilaterally deaf CI users. All participants were native speakers of Mandarin Chinese. CI users were divided into two groups according to thresholds in the nonimplanted ear: (1) single-sided deaf (SSD); pure-tone thresholds <25 dB HL at all audiometric frequencies, and (2) Asymmetric hearing loss (AHL; one or more thresholds > 25 dB HL). SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male or female talkers). The target sentence was always presented via loudspeaker directly in front of the listener (0°), and the maskers were either colocated with the target (0°) or spatially separated from the target at ±90°. Three segregation cue conditions were tested to measure masking release (MR) relative to the baseline condition: (1) Talker sex, (2) Spatial, and (3) Talker sex + Spatial. For CI users, SRTs were measured with the CI on or off.

RESULTS

Binaural MR was significantly better for the NH group than for the AHL or SSD groups ( P < 0.001 in all cases). For the NH group, mean MR was largest with the Talker sex + spatial cues (18.8 dB) and smallest for the Talker sex cues (10.7 dB). In contrast, mean MR for the SSD group was largest with the Talker sex + spatial cues (14.7 dB), and smallest with the Spatial cues (4.8 dB). For the AHL group, mean MR was largest with the Talker sex + spatial cues (7.8 dB) and smallest with the Talker sex (4.8 dB) and the Spatial cues (4.8 dB). MR was significantly better with the CI on than off for both the AHL ( P = 0.014) and SSD groups ( P < 0.001). Across all unilaterally deaf CI users, monaural (acoustic ear alone) and binaural MR were significantly correlated with unaided pure-tone average thresholds in the nonimplanted ear for the Talker sex and Talker sex + spatial conditions ( P < 0.001 in both cases) but not for the Spatial condition.

CONCLUSION

Although the CI benefitted unilaterally deaf listeners' segregation of competing speech, MR was much poorer than that observed in NH listeners. Different from previous findings with steady noise maskers, the CI benefit for segregation of competing speech from a different talker sex was greater in the SSD group than in the AHL group.

Cochlear Implantation After Intralabyrinthine Schwannoma Microsurgical Resection

ABSTRACT

Cochlear implantation after microsurgical resection of intralabyrinthine schwannomas has shown promising results in a limited number of small studies with safe and favorable outcomes. Cochlear implantation is a mainstream treatment for advanced bilateral sensorineural hearing loss and, more recently, has been applied to patients with single-sided deafness.The case presented is a 66-year-old gentleman with a history of progressive right-sided sensorineural hearing loss and bothersome tinnitus with a right intralabyrinthine schwannoma involving the semicircular canals, vestibule, and basal turn of the cochlea. The authors describe concomitant cochlear implantation after microsurgical resection of an intralabyrinthine schwannoma. Intralabyrinthine schwannomas represent an uncommon subtype of benign tumors arising from the terminal branches of the vestibulocochlear nerve. Symptoms often include sensorineural hearing loss, dizziness, and tinnitus, and in this location, symptoms often arise at a small tumor size. In this featured case, we present a patient who underwent gross total tumor resection and cochlear implantation for hearing rehabilitation and treatment of tinnitus. Six months after surgery, the patient achieved good device performance, scoring 46% on consonant-nucleus-consonant word testing and 66% on AzBio sentence testing, and subjective improvement in his tinnitus.

Evolution of the candidacy requirements and patient perioperative assessment protocols for cochlear implantation

Cochlear implantation as an approved clinical therapy ushered in an exciting era of innovation for the treatment of hearing loss. The U.S. Food and Drug Administration approved the use of cochlear implants as a treatment option for adults with profound sensorineural hearing loss in 1985. The landscape for treating adults and children with significant hearing loss has changed dramatically over the last three decades. The purpose of this paper is to examine the evolving regulatory process and changes to clinical care. A significant emerging trend in cochlear implantation is the consideration of steroids to preserve hearing during and following surgery. This parallels the quest for hearing preservation in noise-induced hearing disorders, especially considering the current interest in biological drug therapies in this population. The future will likely usher in an era of combination therapeutics utilizing drugs and cochlear implantation. For over 30+ years and following regulatory compliance, the Rocky Mountain Ear Center has developed an extensive candidacy and outcome assessment protocol. This systematic approach evaluates both unaided and aided auditory performance during candidacy stages and post-implantation. Adjunctive measures of cognition and quality-of-life augment the auditory assessment in specific populations. Practical insights into lessons learned have directed further clinical research and have resulted in beneficial changes to clinical care.

Treated large posterior fossa vestibular schwannoma and meningioma: Hearing outcome and willingness-to-accept brain implant for unilateral deafness

Background/Objective

To compare functional hearing and tinnitus outcomes in treated large (~ 3 cm) vestibular schwannoma (VS) and posterior fossa meningioma cohorts, and construct willingness-to-accept profiles for an experimental brain implant to treat unilateral hearing loss.

Methods

A two-way MANOVA model with two independent variables (tumor type; time from treatment) and three dependent variables (hearing effort of tumor ear; abbreviated Speech, Spatial, and Qualities of Hearing scale (SSQ12); Tinnitus Functional Index (TFI)) was used to analyze data from VS (N = 32) and meningioma (N = 50) patients who were treated at a tertiary care center between 2010 and 2020. A query to probe acceptance of experimental treatment for hearing loss relative to expected benefit was used to construct willingness-to-accept profiles.

Results

Tumor type was statistically significant on the combined dependent variables analysis (F[3, 76] = 19.172, p < .0005, Wilks' Λ = 0.569). Meningioma showed better outcome for hearing effort (F[1, 76] = 14.632, p < .0005) and SSQ12 (F[1, 76] = 16.164, p < .0005), but not for TFI (F[1, 76] = 1.247, p = .268) on univariate two-way ANOVA analyses. Superior hearing effort and SSQ12 indices in the short-term (< 2 years) persisted in the long-term (> 2 years) (p ≤ .017). At the 60% speech understanding level, 77% of respondents would accept an experimental brain implant.

Conclusion

Hearing outcome is better for posterior fossa meningioma compared to VS. Most patients with hearing loss in the tumor ear would consider a brain implant if the benefit level would be comparable to a cochlear implant.

Level of Evidence

2.

Single-Sided Deafness: Emotional and Social Handicap, Impact on Health Status and Quality of Life, Functional Hearing, and the Effects of Cochlear Implantation

OBJECTIVE

To evaluate the functional and subjective outcomes in individuals with single-sided deafness (SSD) treated with a cochlear implant (CI).

METHODS

Eighty-one adult CI users with SSD participated in this study. Functional assessments consisted of speech in noise testing and localization. Subjective assessments consisted of the Speech Spatial Quality of Hearing Scale, the Tinnitus Reaction Questionnaire, the Abbreviated Profile of Hearing Aid Benefit questionnaire, the Hearing Handicap Inventory for Adults questionnaire, and the Glasgow Health Status Inventory and the Glasgow Benefit Inventory questionnaires.

RESULTS

SSD has remarkable consequences on quality of life (QoL) and imposes a substantial emotional and social handicap on the individuals. Self-reported QoL improved after CI with tinnitus intrusion significantly reduced as early as 3 months post-CI. A significant improvement was seen in all speech understanding in noise configurations. Localization ability significantly improved with CI on.

CONCLUSION

Our findings demonstrate that SSD reduces social and psychological QoL and imposes a remarkable level of handicap as per general and specific self-assessments tool. CI provided a significant improvement in function including speech understanding in noise and localization ability, as well as improved QoL and reduced tinnitus significantly in both the early and long terms.

Long-Term Improvement in Localization for Cochlear Implant Users with Single-Sided Deafness

OBJECTIVES/HYPOTHESIS

To assess whether early, significant improvements in sound source localization observed in cochlear implant (CI) recipients with normal hearing (NH) in the contralateral ear are maintained after 5 years of CI use.

STUDY DESIGN

Prospective, repeated measures study.

METHODS

Participants were recruited from a sample of CI + NH listeners (n = 20) who received their device as part of a prospective clinical trial investigating outcomes of CI use for adult cases of single-sided deafness. Sound source localization was assessed annually after the clinical trial endpoint (1-year post-activation). Listeners were asked to indicate the perceived sound source for a broadband noise burst presented randomly at varied intensity levels from one of 11 speakers along a 180° arc. Performance was quantified as root-mean-squared (RMS) error.

RESULTS

Linear mixed models showed superior post-activation performance was maintained with long-term CI use as compared to preoperative abilities (P < .001). Unexpectedly, a significant improvement (P = .009) in sound source localization was observed over the long-term post-activation period (1-5 years). To better understand these long-term findings, the response patterns for the 11 participants who were evaluated at the 1- and 5-year visits were reviewed. This subgroup demonstrated a significant improvement in RMS error (P = .020) and variable error (P = .031), indicating more consistent responses at the 5-year visit.

CONCLUSION

Adult CI + NH listeners experience significant improvements in sound source localization within the initial weeks of listening experience, with additional improvements observed after long-term device use. The present sample demonstrated significant improvements between the 1-year and 5-year visits, with greater accuracy and consistency noted in their response patterns.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2453-2458, 2022.

External Validation of Cochlear Implant Screening Tools Demonstrates Modest Generalizability

OBJECTIVE

To assess the clinical application of five recently published cochlear implant (CI) candidacy evaluation (CICE) referral screening tools through external validation.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary otology/neurotology practice.

PATIENTS

Adults who underwent CICE between December 2020 and September 2021.

INTERVENTIONS

CICE referral screening tools versus CI candidacy criteria.

MAIN OUTCOME MEASURES

CICE screening tool performance, based on the ability to identify patients who met the CI candidacy criteria, was evaluated. CI candidacy criteria were defined as best-aided AzBio sentences at +10 signal-to-noise ratio and either 60% or less accuracy to reflect traditional criteria used in clinical settings or 40% or less accuracy (only patients 65 years or older) to reflect Medicare-eligible criteria.

RESULTS

Screening criteria of proposed CICE referral tools vary widely across pure-tone average and word recognition scores. When screened by traditional criteria, the sensitivities and specificities of these referral tools varied from 40 to 77% and from 22 to 86%, respectively. When screened by Medicare-eligible criteria, sensitivities and specificities varied from 41 to 81% and from 24 to 91%, respectively. The screening tool proposed by Zwolan et al. ( Otol Neurotol 2020;41(7):895-900) demonstrated the best overall performance for traditional (Youden's J , 0.37; sensitivity, 62%; specificity, 75%) and Medicare-eligible patients (Youden's J , 0.44; sensitivity, 66%; specificity, 78%). All screening tools performed worse on the validation cohort compared with their respective development cohorts.

CONCLUSIONS

Current tools for determining CICE referral have diverse screening criteria. These combinations of pure-tone average and word recognition score are modestly successful at identifying CI candidates.

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

PURPOSE OF REVIEW

Children and adults with unilateral or asymmetric hearing loss (UHL/AHL) have poorer spatial hearing (e.g. speech understanding in complex maskers and localization) and quality of life compared with peers with normal hearing bilaterally. Patients with UHL/AHL experience limited benefits with contralateral-routing technologies (e.g. bone conduction, CROS hearing aid systems). Cochlear implantation allows for stimulation of the auditory pathway for the poorer hearing ear. The present study reviews the recent literature on outcomes of cochlear implant use for recipients with UHL/AHL.

RECENT FINDINGS

Recent research corroborates previous investigations of the significant benefits on measures of spatial hearing, tinnitus severity and quality of life for adult cochlear implant recipients. These benefits are also observed in pediatric cochlear implant recipients, with an association of better outcomes with younger ages at implantation for congenital cases and shorter durations of UHL/AHL for acquired cases. In addition, randomized trials demonstrate better outcomes with cochlear implant use versus contralateral-routing technologies.

SUMMARY

Cochlear implantation supports better spatial hearing and quality of life in children and adults with UHL/AHL as compared to alternative listening conditions. Current research supports the expansion of candidacy criteria and insurance coverage for cochlear implantation for patients with UHL/AHL to improve their binaural hearing.

American Cochlear Implant Alliance Task Force Guidelines for Clinical Assessment and Management of Adult Cochlear Implantation for Single-Sided Deafness

The indications for cochlear implantation have expanded to include individuals with profound sensorineural hearing loss in the impaired ear and normal hearing (NH) in the contralateral ear, known as single-sided deafness (SSD). There are additional considerations for the clinical assessment and management of adult cochlear implant candidates and recipients with SSD as compared to conventional cochlear implant candidates with bilateral moderate to profound sensorineural hearing loss. The present report reviews the current evidence relevant to the assessment and management of adults with SSD. A systematic review was also conducted on published studies that investigated outcomes of cochlear implant use on measures of speech recognition in quiet and noise, sound source localization, tinnitus perception, and quality of life for this patient population. Expert consensus and systematic review of the current literature were combined to provide guidance for the clinical assessment and management of adults with SSD.

Masked Speech Recognition as a Function of Masker Location for Cochlear Implant Users With Single-Sided Deafness

PURPOSE

Cochlear implant (CI) recipients with normal or near normal hearing (NH) in the contralateral ear, referred to as single-sided deafness (SSD), experience significantly better speech recognition in noise with their CI than without it, although reported outcomes vary. One possible explanation for differences in outcomes across studies could be differences in the spatial configurations used to assess performance. This study compared speech recognition for different spatial configurations of the target and masker, with test materials used clinically.

METHOD

Sixteen CI users with SSD completed tasks of masked speech recognition presented in five spatial configurations. The target speech was presented from the front speaker (0° azimuth). The masker was located either 90° or 45° toward the CI-ear or NH-ear or colocated with the target. Materials were the AzBio sentences in a 10-talker masker and the Bamford-Kowal-Bench Speech-in-Noise test (BKB-SIN; four-talker masker). Spatial release from masking (SRM) was computed as the benefit associated with spatial separation relative to the colocated condition.

RESULTS

Performance was significantly better when the masker was separated toward the CI-ear as compared to colocated. No benefit was observed for spatial separations toward the NH-ear. The magnitude of SRM for spatial separations toward the CI-ear was similar for 45° and 90° when tested with the AzBio sentences, but a larger benefit was observed for 90° as compared to 45° for the BKB-SIN.

CONCLUSIONS

Masked speech recognition in CI users with SSD varies as a function of the spatial configuration of the target and masker. Results supported an expansion of the clinical test battery at the study site to assess binaural hearing abilities for CI candidates and recipients with SSD. The revised test battery presents the target from the front speaker and the masker colocated with the target, 90° toward the CI-ear, or 90° toward the NH-ear.

The P300 Auditory Event-Related Potential May Predict Segregation of Competing Speech by Bimodal Cochlear Implant Listeners

Compared to normal-hearing (NH) listeners, cochlear implant (CI) listeners have greater difficulty segregating competing speech. Neurophysiological studies have largely investigated the neural foundations for CI listeners' speech recognition in quiet, mainly using the P300 component of event-related potentials (ERPs). P300 is closely related to cognitive processes involving auditory discrimination, selective attention, and working memory. Different from speech perception in quiet, little is known about the neurophysiological foundations for segregation of competing speech by CI listeners. In this study, ERPs were measured for a 1 vs. 2 kHz contrast in 11 Mandarin-speaking bimodal CI listeners and 11 NH listeners. Speech reception thresholds (SRTs) for a male target talker were measured in steady noise or with a male or female masker. Results showed that P300 amplitudes were significantly larger and latencies were significantly shorter for the NH than for the CI group. Similarly, SRTs were significantly better for the NH than for the CI group. Across all participants, P300 amplitude was significantly correlated with SRTs in steady noise (r = -0.65, p = 0.001) and with the competing male (r = -0.62, p = 0.002) and female maskers (r = -0.60, p = 0.003). Within the CI group, there was a significant correlation between P300 amplitude and SRTs with the male masker (r = -0.78, p = 0.005), which produced the most informational masking. The results suggest that P300 amplitude may be a clinically useful neural correlate of central auditory processing capabilities (e.g., susceptibility to informational masking) in bimodal CI patients.

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

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.

Cochlear implant in vestibular schwannomas: long-term outcomes and critical analysis of indications

PURPOSE

To describe our institutional experience in cochlear implantation after vestibular schwannoma (VS) resection, and compare the audiological outcomes between sporadic and neurofibromatosis type 2 (NF2) VS sub-cohorts of patients, and in relation to preoperative contralateral hearing.

METHODS

Seventeen patients (8 sporadic and 9 NF2-associated VSs) who had undergone VS resection and cochlear implant (CI) were analyzed retrospectively. Audiological outcomes at 24 months were correlated with preoperative clinical variables. The results according to VS type (sporadic vs. NF2-associated) and contralateral hearing (impaired vs. normal) were compared.

RESULTS

Fourteen CIs were actively used by the patients (77.8%). Twenty-four months after CI activation, the median postoperative PTA (pure tone average) was 45.6 dB nHL and a measurable WRS (Word Recognition Score) was achieved by 44.4% of patients (median WRS = 40%). The median postoperative PTA in the implanted ear resulted better in the group with an impaired contralateral hearing (36.3 dB nHL vs. 78.8 dB nHL, p = 0.019). Good preoperative contralateral hearing status (A-B classes of AAO-HNS) was a negative prognostic factor for CI performance on open-set discrimination (OR = 28.0, 95% CI 2.07-379.25, p = 0.012).

CONCLUSIONS

CI is a viable rehabilitative option for patients with sporadic or NF2-associated VS. A good contralateral hearing adversely affects CI outcome and should be taken into consideration for patients' selection and rehabilitation programs.

Speech Perception Performance Growth and Benchmark Score Achievement After Cochlear Implantation for Single-Sided Deafness

OBJECTIVES

Compare speech perception performance growth and benchmark score achievement among adult cochlear implant (CI) recipients with single-sided deafness (SSD) versus bilateral moderate to profound hearing loss.

STUDY DESIGN

Retrospective matched cohort analysis.

SETTING

Tertiary referral center.

PATIENTS

Adults with SSD or bilateral moderate to profound hearing sensorineural hearing loss who underwent cochlear implantation from 2014 to 2019.

INTERVENTIONS

Cochlear implantation.

MAIN OUTCOME MEASURES

Time-to-benchmark speech perception score (CNC, AzBio in quiet) and speech performance within first postoperative year.

RESULTS

Thirty-three SSD patients were matched to 66 bilateral hearing loss patients (referent cohort) for duration of deafness and preoperative ipsilateral CNC scores. Although SSD patients were more likely to achieve benchmark CNC scores more quickly compared with matched referents, this difference did not reach statistical significance (HR 1.72; 95% CI 0.78-3.82; p = 0.18). AzBio scores showed similar trends (HR 1.40; 95% CI 0.66-2.98; p = 0.38). At last follow-up, the SSD cohort had lower CNC (median 54% vs. 62%; p = 0.019) and AzBio scores (median 72% vs. 84%; p = 0.029) compared to the referent cohort.

CONCLUSIONS

No significant difference in speech perception performance growth (i.e., time-to-benchmark speech perception score) was identified between SSD and bilateral hearing loss CI recipients, although patients with bilateral hearing loss achieved higher scores in the implanted ear within the first year of follow-up.

Prevalence of Single-Sided Deafness in the United States

OBJECTIVES/HYPOTHESIS

The aim of this study was to obtain a reliable estimate of single-sided deafness (SSD) prevalence in the adult U.S.

POPULATION

METHODS

A cross-sectional national epidemiologic study was performed. Participants were included from the National Health and Nutrition Examination Survey (NHANES). Each cohort includes a nationally representative sample of approximately 5,000 noninstitutionalized civilians. Subjects 20 years old and over with audiometric testing were included. SSD was defined as normal hearing (pure-tone average [PTA] of ≤25 dB) in one ear and severe or worse hearing (PTA > 70 dB) in the other, using both three- and four-frequency PTA definition. Prevalence was measured as a raw number (n) and percentage (%) of the sample. Weighted estimates of prevalence were calculated based on the 2019 U.S. population census.

RESULTS

An estimated 345,064 Americans (estimated prevalence of 0.14%, 95% confidence interval = 0.08-0.24) had SSD. SSD was more prevalent in individuals 60 to 79 years of age (estimated 155,917 U.S. adults, prevalence of 0.25%). A higher prevalence of SSD was noted among women compared to men (215,430 U.S. adult women, prevalence of 0.17% vs. 131,726 U.S. adult men, prevalence of 0.11%). Using a three-frequency PTA definition resulted in an estimated prevalence of 0.11%. Finally, 27% of adults with SSD reported having "good" or "excellent" hearing despite their hearing loss.

CONCLUSIONS

The prevalence of SSD in the United States is estimated at 0.11%-0.14% (271,122 to 345,064 adults), depending on PTA definition used. These individuals could potentially benefit from auditory rehabilitation, including cochlear implantation.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

Rehabilitation for unilateral deafness - Narrative review comparing a novel bone conduction solution with existing options

Patients with single sided deafness (SSD) struggle with sound localization and speech in noise. Existing treatment options include contralateral routing of signal (CROS) systems, percutaneous bone conduction hearing devices (BCHDs), passive transcutaneous BCHDs, active BCHDs, and cochlear implants. Implanted devices provide benefits in speech in noise compared to CROS devices. Percutaneous BCHDs transmit sound efficiently but have aesthetic drawbacks and skin complications. Scalp attenuation impacts passive transcutaneous BCHD performance. Active BCHDs overcome these issues and provide benefits for speech in noise. Cochlear implantation is the only existing option that restores binaural input but introduces electrical rather than acoustic stimuli to the deaf ear. Active BCHDs have been designed to maintain efficient sound transmission and avoid chronic skin irritation and cosmetic concerns that may occur with percutaneous BCHDs. Cochlear implantation may be a superior option for recently deafened SSD patients, though this requires further study. The duration of deafness, patient age and comorbidities, and a shared decision-making model among patients, surgeons, and audiologists should be considered in device selection. The aim of this manuscript is to review available devices, discuss surgical considerations for implantable devices, review available published results for speech in noise and sound quality with each device, and provide an overview to guide shared decision making for patients and providers. This review consolidates available literature and reviews experience with a newer active transcutaneous active BCHD available for use in the SSD population.

Short-term outcomes of cochlear implantation for single-sided deafness compared to bone conduction devices and contralateral routing of sound hearing aids-Results of a Randomised controlled trial (CINGLE-trial)

Single-sided deafness (SSD) leads to difficulties with speech perception in noise, sound localisation, and sometimes tinnitus. Current treatments (Contralateral Routing of Sound hearing aids (CROS) and Bone Conduction Devices (BCD)) do not sufficiently overcome these problems. Cochlear implants (CIs) may help. Our aim was to evaluate these treatments in a Randomised Controlled Trial (RCT). Adult SSD patients were randomised using a web-based randomisation tool into one of three groups: CI; trial period of 'first BCD, then CROS'; trial period of 'first CROS, then BCD'. After these trial periods, patients opted for BCD, CROS, or No treatment. The primary outcome was speech perception in noise (directed from the front (S0N0)). Secondary outcomes were speech perception in noise with speech directed to the poor ear and noise to the better ear (SpeNbe) and vice versa (SbeNpe), sound localisation, tinnitus burden, and disease-specific quality of life (QoL). We described results at baseline (unaided situation) and 3 and 6 months after device activation. 120 patients were randomised. Seven patients did not receive the allocated intervention. The number of patients per group after allocation was: CI (n = 28), BCD (n = 25), CROS (n = 34), and No treatment (n = 26). In S0N0, the CI group performed significantly better when compared to baseline, and when compared to the other groups. In SpeNbe, there was an advantage for all treatment groups compared to baseline. However, in SbeNpe, BCD and CROS groups performed worse compared to baseline, whereas the CI group improved. Only in the CI group sound localisation improved and tinnitus burden decreased. In general, all treatment groups improved on disease-specific QoL compared to baseline. This RCT demonstrates that cochlear implantation for SSD leads to improved speech perception in noise, sound localisation, tinnitus burden, and QoL after 3 and 6 months of follow-up. For most outcome measures, CI outperformed BCD and CROS. Trial registration: Netherlands Trial Register (www.trialregister.nl): NTR4580, CINGLE-trial.

Influence of Cochlear Implant Use on Perceived Listening Effort in Adult and Pediatric Cases of Unilateral and Asymmetric Hearing Loss

OBJECTIVE

Assess the influence of cochlear implant (CI) use on the perceived listening effort of adult and pediatric subjects with unilateral hearing loss (UHL) or asymmetric hearing loss (AHL).

STUDY DESIGN

Prospective cohort.

SETTING

Tertiary referral center.

PATIENTS

Adults and children with UHL or AHL.

INTERVENTION

Cochlear implantation. Subjects received their CI as part of a clinical trial assessing the effectiveness of cochlear implantation in cases of UHL and AHL.

MAIN OUTCOME MEASURES

Responses to the Listening Effort pragmatic subscale on the Speech, Spatial, and Qualities of Hearing Scale (SSQ) or SSQ for Children with Impaired Hearing (SSQ-C) were compared over the study period. Subjects or their parents completed the questionnaires preoperatively and at predetermined postactivation intervals. For the adult subjects, responses were compared to word recognition in quiet and sentence recognition in noise.

RESULTS

Forty adult subjects (n = 20 UHL, n = 20 AHL) and 16 pediatric subjects with UHL enrolled and underwent cochlear implantation. Subjects in all three groups reported a significant reduction in perceived listening effort within the initial months of CI use (p < 0.001; η2 ≥ 0.351). The perceived benefit was significantly correlated with speech recognition in noise for the adult subjects with UHL at the 12-month interval (r(20) = .59, p = 0.006).

CONCLUSIONS

Adult and pediatric CI recipients with UHL or AHL report a reduction in listening effort with CI use as compared to their preoperative experiences. Use of the SSQ and SSQ-C Listening Effort pragmatic subscale may provide additional information about a CI recipient's experience beyond the abilities measured in the sound booth.

Cost Effectiveness of Cochlear Implantation in Single-Sided Deafness

OBJECTIVE

To analyze the cost effectiveness of cochlear implantation (CI) for the treatment of single-sided deafness (SSD).

STUDY DESIGN

Cost-utility analysis in an adapted Markov model.

SETTING

Adults with single-sided deafness in a high-income country.

INTERVENTION

Unilateral CI was compared with no intervention.

MAIN OUTCOME MEASURE

Incremental cost-effectiveness ratios were compared with different cost-effectiveness thresholds ($10,000 to $150,000) for different age, sex, and cost combinations. The calculations were based on the quality-adjusted life year (QALY), national life expectancy tables, and different cost settings. The health utility values for the QALY were either directly collected from published data, or, derived from published data using a regression model of multiple utility indices (regression estimate).

RESULTS

The regression estimate showed an increase of the health utility value from 0.62 to 0.74 for SSD patients who underwent CI. CI for SSD was cost effective for women up to 64 years ($50,000 per-QALY threshold), 80 years ($100,000 per-QALY threshold), and 86 years ($150,000 per-QALY threshold). For men, these values were 58, 77, and 84, respectively. Changing the discount rate by up to 5% further increased the cutoff ages up to 5 years. A detailed cost and age sensitivity analysis is presented and allows testing for cost effectiveness in local settings worldwide.

CONCLUSIONS

CI is a cost-effective option to treat patients with SSD.

Intraoperative Cochlear Nerve Monitoring for Vestibular Schwannoma Resection and Simultaneous Cochlear Implantation in Neurofibromatosis Type 2: A Case Series

BACKGROUND

Neurofibromatosis type 2 (NF2) often results in profound hearing loss and cochlear implantation is an emerging hearing rehabilitation option. However, cochlear implant (CI) outcomes in this population vary, and intraoperative monitoring to predict cochlear nerve viability and subsequent outcomes is not well-established.

OBJECTIVE

To review the use of intraoperative electrically evoked cochlear nerve monitoring in patients with NF2 simultaneous translabyrinthine (TL) vestibular schwannoma (VS) resection and cochlear implantation.

METHODS

A retrospective review was performed of 3 patients with NF2 that underwent simultaneous TL VS resection and cochlear implantation with electrical auditory brainstem response (eABR) measured throughout tumor resection. Patient demographics, preoperative assessments, surgical procedures, and outcomes were reviewed.

RESULTS

Patients 1 and 3 had a reliable eABR throughout tumor removal. Patient 2 had eABR pretumor removal, but post-tumor removal eABR presence could not be reliably determined because of electrical artifact interference. All patients achieved auditory percepts upon CI activation. Patients 1 and 2 experienced a decline in CI performance after 1 yr and after 3 mo, respectively. Patient 3 continues to perform well at 9 mo. Patients 2 and 3 are daily users of their CI.

CONCLUSION

Cochlear implantation is attainable in cases of NF2-associated VS resection. Intraoperative eABR may facilitate cochlear nerve preservation during tumor removal, though more data and long-term outcomes are needed to refine eABR methodology and predictive value for this population.

Cochlear Implantation in Sporadic Vestibular Schwannoma and Other Retrocochlear Pathology: A Case Series

OBJECTIVE

To describe outcomes with cochlear implantation (CI) for rehabilitation of hearing loss in patients with sporadic vestibular schwannomas (VS) and other retrocochlear pathologies.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary-care center.

PATIENTS

Twenty three cases in 19 patients (53% men, mean age 55.8 yr) with non-neurofibromatosis type 2 related retrocochlear pathology.

INTERVENTIONS

Unilateral or bilateral CI.

MAIN OUTCOME MEASURES

Word recognition score, device usage.

RESULTS

Etiology of deafness included sporadic VS (n = 9, 39%), radiation after head and neck or central nervous system (CNS) malignancy (n = 8, 35%), superficial siderosis (n = 3, 13%), neurosarcoidosis (n = 2, 9%), and pontine stroke (n = 1, 4%). Mean follow-up duration was 2.3 years (standard deviation [SD] 3.0; range, 0.2-9.4). Auditory perception was achieved in 20 out of 22 patients (91%) who have been activated. Mean WRS in patients with sporadic VS was 18% (SD 20; range, 0-44). Mean WRS in patients with non-VS retrocochlear pathology was 55% (SD 30; range, 0-94). Data logs showed 7.0 h/d of average use (SD 4.3; range, 0-13).

CONCLUSIONS

Appropriately selected patients with retrocochlear pathology may benefit from CI so long as the patient has a cochlear fluid signal and an intact cochlear nerve. Patients with sporadic VS patients and normal contralateral hearing exhibited guarded outcomes with CI, whereas most patients with non-VS retrocochlear pathologies demonstrated open-set speech understanding scores comparable to or slightly worse than conventional CI candidates. Since variable performance benefit is observed with CI in patients with retrocochlear pathology, counseling is imperative to align patient expectations with realistic outcomes.

Cochlear Implantation in Adults With Single-sided Deafness: Outcomes and Device Use

OBJECTIVE

To describe our experience with adults undergoing cochlear implantation (CI) for treatment of single-sided deafness (SSD).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Fifty-three adults with SSD.

INTERVENTIONS

Unilateral CI.

MAIN OUTCOME MEASURES

Speech perception testing in quiet and noise, tinnitus suppression, and device usage from datalogs.

RESULTS

The mean age at CI was 53.2 years (SD 11.9). The mean duration of deafness was 4.0 years (SD 7.8). The most common etiology was idiopathic sudden SNHL (50%). Word recognition improved from 8.7% (SD 15) preoperatively to 61.8% (SD 20) at a mean follow-up of 3.3 years (SD 1.8) (p < 0.0001). Adaptive speech recognition testing in the "binaural with CI" condition (speech directed toward the front and noise toward the normal hearing ear) revealed a significant improvement by 2.6-dB SNR compared to the preoperative unaided condition (p = 0.0002) and by 3.6-dB SNR compared to when a device to route sound to the contralateral side was used (p < 0.0001). Tinnitus suppression was reported to be complete in 23 patients (43%) and improved in 20 patients (38%) while the device was on. The addition of the CI did not lead to a decrement in hearing performance in any spatial configuration. Device usage averaged 8.7 (SD 3.7) hours/day.

CONCLUSIONS

Cochlear implantation in adult SSD patients can suppress tinnitus and achieve speech perception outcomes comparable with CI in conventional candidates. Modest improvements in spatial hearing were also observed and primarily attributable to the head shadow effect. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes.