[Patient-related outcome measures (PROM) in adult cochlear implant patients]

BACKGROUND

Cochlear implants (CI) provide individuals with severe sensorineural hearing loss the opportunity for artificial auditory perception. The standardized documentation of speech intelligibility tests is widespread, while the systematic capture of patient-related outcome measures (PROMs) remains inconsistent.

METHODOLOGY

Relevant PROM instruments were evaluated and selected based on the criteria of dissemination, clarity, and relevance, integrated into routine clinical practice, and tested at longitudinal time points.

RESULTS

A total of three PROM instruments were selected and successfully integrated into the clinical routine. The comparison of 2 measurement points from 25 individuals showed improvements in subjective speech comprehension and tinnitus perception.

CONCLUSION

This study demonstrates the clinical implementation and integration of PROMs in adult CI candidates and patients. The PROMs are a promising tool to support various phases of treatment, both as a decision aid for potential CI candidates and for monitoring after implantation.

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.

Benefits of Cochlear Implantation for Older Adults With Asymmetric Hearing Loss

OBJECTIVE(S)

FDA-approved indications for cochlear implantation include patients with severe-to-profound unilateral hearing loss (UHL) or asymmetric hearing loss (AHL); however, these indications are not covered for Medicare beneficiaries. We assessed the outcomes of cochlear implant (CI) use for older adults with UHL or AHL.

METHODS

Eighteen older adults (≥65 years of age at surgery) with UHL/AHL participated in a prospective, longitudinal investigation evaluating outcomes of CI use. Speech recognition for the affected ear was evaluated with consonant-nucleus-consonant (CNC) words. Spatial hearing was assessed with measures of sound source localization and sentence recognition in noise. The target sentence was presented from the front and the masker was either co-located with the target (SoNo), presented toward the affected ear (SoNci) or contralateral ear (SoNcontra). Perceived benefit was assessed with the Speech, Spatial, and Qualities of Hearing scale (SSQ) and the Tinnitus Handicap Inventory (THI).

RESULTS

Participants experienced significant improvements with CI use for CNC words (mean [SD]; preop: 8% [10%], 1 yr: 51% [22%], 5 yr: 50% [19%]), masked sentence recognition (SoNcontra preop: 5% [6%], 1 yr: 22% [15%], 5 yr: 41% [14%]), and localization (preop: 76° [18°], 1 yr: 40° [11°], 5 yr: 41° [14°]), and reported significant improvements in hearing abilities (SSQ Spatial Hearing preop: 3 [1], 1 yr: 6 [2], 5 yr: 6 [2]) and tinnitus severity (THI preop: 16 [18], 1 yr: 4 [14], 5 yr: 6 [12]).

CONCLUSION

Older adults with UHL/AHL experience significant improvements in speech recognition, spatial hearing, and subjective perceptions (e.g., hearing abilities and tinnitus severity) with a CI as compared to pre-operative abilities.

LEVEL OF EVIDENCE

IV Laryngoscope, 2024.

Speech-in-Noise Assessment in the Routine Audiologic Test Battery: Relationship to Perceived Auditory Disability

OBJECTIVES

Self-assessment of perceived communication difficulty has been used in clinical and research practices for decades. Such questionnaires routinely assess the perceived ability of an individual to understand speech, particularly in background noise. Despite the emphasis on perceived performance in noise, speech recognition in routine audiologic practice is measured by word recognition in quiet (WRQ). Moreover, surprisingly little data exist that compare speech understanding in noise (SIN) abilities to perceived communication difficulty. Here, we address these issues by examining audiometric thresholds, WRQ scores, QuickSIN signal to noise ratio (SNR) loss, and perceived auditory disability as measured by the five questions on the Speech Spatial Questionnaire-12 (SSQ12) devoted to speech understanding (SSQ12-Speech5).

DESIGN

We examined data from 1633 patients who underwent audiometric assessment at the Stanford Ear Institute. All individuals completed the SSQ12 questionnaire, pure-tone audiometry, and speech assessment consisting of ear-specific WRQ, and ear-specific QuickSIN. Only individuals with hearing threshold asymmetries ≤10 dB HL in their high-frequency pure-tone average (HFPTA) were included. Our primary objectives were to (1) examine the relationship between audiometric variables and the SSQ12-Speech5 scores, (2) determine the amount of variance in the SSQ12-Speech5 scores which could be predicted from audiometric variables, and (3) predict which patients were likely to report greater perceived auditory disability according to the SSQ12-Speech5.

RESULTS

Performance on the SSQ12-Speech5 indicated greater perceived auditory disability with more severe degrees of hearing loss and greater QuickSIN SNR loss. Degree of hearing loss and QuickSIN SNR loss were found to account for modest but significant variance in SSQ12-Speech5 scores after accounting for age. In contrast, WRQ scores did not significantly contribute to the predictive power of the model. Degree of hearing loss and QuickSIN SNR loss were also found to have moderate diagnostic accuracy for determining which patients were likely to report SSQ12-Speech5 scores indicating greater perceived auditory disability.

CONCLUSIONS

Taken together, these data indicate that audiometric factors including degree of hearing loss (i.e., HFPTA) and QuickSIN SNR loss are predictive of SSQ12-Speech5 scores, though notable variance remains unaccounted for after considering these factors. HFPTA and QuickSIN SNR loss-but not WRQ scores-accounted for a significant amount of variance in SSQ12-Speech5 scores and were largely effective at predicting which patients are likely to report greater perceived auditory disability on the SSQ12-Speech5. This provides further evidence for the notion that speech-in-noise measures have greater clinical utility than WRQ in most instances as they relate more closely to measures of perceived auditory disability.

Benefits of unilateral cochlear implantation in adults with asymmetric hearing loss: Audiologic and patient-related outcome measures

PURPOSE

To investigate the benefits of cochlear implantation in adults with single-sided deafness (SSD) and asymmetric hearing loss (AHL).

STUDY DESIGN

Prospective within-subjects repeated-measures.

SETTING

Two tertiary cochlear implant centers.

PATIENTS

Fourteen adults with severe-to-profound sensorineural hearing loss in the worse hearing ear and up to moderate SNHL in the better hearing ear.

INTERVENTION

Cochlear implantation in the worse hearing ear.

MAIN OUTCOME MEASURES

Consonant-nucleus-consonant (CNC) test, AzBio sentence test in noise, and lateralization testing were conducted preoperatively and at 3-, 6-, and 12-months post-activation. Patient-related outcomes were measured using the Speech, Spatial, and Qualities of Hearing Scale and Glasgow Benefit Inventory. Tinnitus Handicap Inventory was administered to subjects with tinnitus.

RESULTS

Mean length of hearing loss in the worse hearing ear was 3.5 years. The mean CNC change scores from baseline were 54.8, 55.9, and 58.9 percentage points at 3-, 6-, and 12-months (p < 0.001). AzBio sentence test in noise demonstrated improved scores in all spatial configurations, although statistically significant in S0N0 (speech front, noise front) only. Lateralization testing showed significant improvement of 22.9, 24.5, and 24.0 percentage points at 3-, 6-, and 12 months post-activation (p = 0.002). All patient-related outcome measures revealed significant improvement.

CONCLUSION

This study demonstrates improved speech perception in noise, sound lateralization, quality of life, and reduction in tinnitus perception in adults with SSD/AHL who undergo cochlear implantation. Our results add to the growing body of evidence that cochlear implant should be offered to this population.

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.

The functional impact of implantable hearing devices in patients with single-sided deafness

Introduction

Single-sided deafness (SSD) is associated with significant functional impairment such as listening speech in noise and localizing sound. To date, studies on the efficacy of CI and BCI for single-sided deafness are conflicting.

Objective

Thus, the objective of our study was to describe and compare the functional outcomes between these devices.

Methods

Thirteen subjects with SSD were prospectively recruited for our study. Six underwent CI and seven received BCI. Word recognition scores (WRS) and disease specific outcome measures were obtained pre-implantation, at 6, and 12 months.

Results

WRS improved both in quiet and in noise for CI and BCI recipients. On the contrary, CI recipients displayed improvement in Speech Spatial Quality (SSQ) scores. A decreasing trend of improvement in APHAB scores were observed for the BCI group.

Conclusion

BCI recipients showed a significant improvement in WRS (in noise). Conversely, CI recipients showed a great improvement in SSQ scores. These preliminary findings suggest that true binaural hearing can only be restored with CI for better SSQ performance. However, BCIs could be recommended to a sub-group of patients, if listening to speech in noise is a priority.

Listening effort and fatigue among cochlear implant users: a scoping review

Introduction

In challenging listening situations, speech perception with a cochlear implant (CI) remains demanding and requires high levels of listening effort, which can lead to increased levels of listening-related fatigue. The body of literature on these topics increases as the number of CI users rises. This scoping review aims to provide an overview of the existing literature on listening effort, fatigue, and listening-related fatigue among CI users and the measurement techniques to evaluate them.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statements were used to conduct the scoping review. The search was performed on PubMed, Scopus, and Web of Science to identify all relevant studies.

Results

In total, 24 studies were included and suggests that CI users experience higher levels of listening effort when compared to normal hearing controls using scales, questionnaires and electroencephalogram measurements. However, executing dual-task paradigms did not reveal any difference in listening effort between both groups. Uncertainty exists regarding the difference in listening effort between unilateral, bilateral, and bimodal CI users with bilateral hearing loss due to ambiguous results. Only five studies were eligible for the research on fatigue and listening-related fatigue. Additionally, studies using objective measurement methods were lacking.

Discussion

This scoping review highlights the necessity for additional research on these topics. Moreover, there is a need for guidelines on how listening effort, fatigue, and listening-related fatigue should be measured to allow for study results that are comparable and support optimal rehabilitation strategies.

Can an individual with low frequency hearing in the candidate ear benefit from a cochlear implant even if they have normal hearing in the other ear?

PURPOSE

To determine hearing preservation and subjective benefit after cochlear implant (CI) surgery in patients with low frequency hearing in the ear to be implanted (i.e., they have partial deafness, PD) and close to normal hearing in the other.

METHODS

There were two study groups. The test group was made up of 12 adult patients (mean age 43.4 years; SD 13.6) with normal hearing or mild hearing loss in one ear, and with PD in the ear to be implanted. The reference group consisted of 12 adult patients (mean age 44.5 years; SD 14.1) who had PD in both ears and who underwent unilateral implantation in their worse ear. Hearing preservation was assessed 1 and 14 months after CI surgery using the Skarzynski Hearing Preservation Classification System. The APHAB questionnaire was used to evaluate the benefit from the CI.

RESULTS

The differences in HP% between the groups were not significant: mean hearing preservation (HP%) in the test group was 82% one month after CI surgery and 75% some 14 months after implantation; corresponding results in the reference group were 71% and 69%. However, on the APHAB background noise subscale, the benefit in the test group was significantly larger than in the reference group.

CONCLUSION

To a large extent it was possible to preserve low-frequency hearing in the implanted ear. This means that individuals with low frequency hearing in the implanted ear (partial deafness) and with normal hearing in the other generally received more benefits from cochlear implantation than did patients with partial deafness in both ears. We conclude that residual low frequency hearing in the ear to be implanted should not be considered a contraindication for a CI in a patient with single-sided deafness.

Cochlear Implantation for Unilateral and Asymmetric Hearing Loss: Long-Term Subjective Benefit

OBJECTIVES

Assess the long-term patterns of perceived tinnitus severity and subjective benefit for adult cochlear implant (CI) users with asymmetric or unilateral hearing loss (AHL or UHL).

METHODS

Forty adults underwent cochlear implantation as part of a prospective clinical trial assessing the outcomes of CI use in cases of AHL (n = 20) and UHL (n = 20). Subjective measures included the Tinnitus Handicap Inventory (THI), the Speech, Spatial, & Qualities of Hearing Scale (SSQ), and the Abbreviated Profile of Hearing Aid Benefit (APHAB). Responses were obtained preoperatively and at routine intervals out to 5 years post-activation.

RESULTS

For subjective benefit, participants with AHL and UHL reported a significant improvement as compared to preoperative abilities, which was maintained with long-term CI use. For perceived tinnitus severity, participants with AHL and UHL reported a significant reduction with CI use as compared to preoperative perceptions. The perceived tinnitus severity significantly differed for the AHL and UHL cohorts over time. This pattern of results is likely influenced by the worse perceived severity levels for the UHL cohort preoperatively and the fluctuating perceived severity levels for some participants in the AHL cohort post-activation.

CONCLUSION

Adults with AHL and UHL report an early, significant reduction in perceived tinnitus severity and improvement in quality of life with CI use that is generally maintained with long-term device use. Questionnaires such as the THI, SSQ, and APHAB may contribute to a more holistic assessment of the benefits of cochlear implantation in this population.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2792-2797, 2023.

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.

[Prospective comparative analysis of cochlear implant patients with single-sided deafness and asymmetric hearing loss with regard to health-related quality of life, tinnitus distress and psychological comorbidities]

BACKGROUND

Patients with single-sided deafness (SSD) and asymmetric hearing loss (AHL) are increasingly being treated with cochlear implants (CI) due to the demonstrated improvements in auditory abilities and quality of life. To date, there are few published studies in which these two groups are comparatively studied. The aim of the current study was to examine which factors differ between those two patient groups, especially preoperatively.

METHODS

A secondary analysis of the previously published raw data of 66 prospectively recruited CI patients (21 SSD/45 AHL) was performed. In addition to the hearing outcome, tinnitus distress (tinnitus questionnaire), health-related quality of life (Nijmegen Cochlear Implant Questionnaire, NCIQ), stress (Perceived Stress Questionnaire, PSQ), and psychological comorbidities (General Depression Scale, ADS‑L and Generalized Anxiety Disorder scale, GAD-7) were assessed in SSD and AHL patients pre- and postoperatively.

RESULTS

Preoperatively, SSD patients showed significantly higher scores in the NCIQ subdomains "elementary" and "advanced sound perception" than the AHL group. Stress (PSQ) and anxiety symptoms (GAD-7) were significantly higher preoperatively in SSD patients than in AHL patients. After CI, these differences were strongly reduced, with minimal differences being detectable between the groups in the investigated domains postoperatively.

CONCLUSION

SSD and AHL patients differ significantly preoperatively in terms of their subjective hearing assessment and psychosocial parameters. In SSD patients, psychological stress factors may have a stronger impact on the quality of life than in AHL patients. These aspects should be taken into account in the preoperative counseling and postoperative rehabilitation.

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.

Comparison of Speech, Spatial, and Qualities of Hearing Scale (SSQ) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) Questionnaires in a Large Cohort of Self-Reported Normal-Hearing Adult Listeners

The Speech, Spatial, and Qualities of Hearing Scale (SSQ) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) are two most commonly used questionnaires in the audiology clinic to assess an individual's self-perception of their hearing ability. Here, we present the outcomes of these two questionnaires on a large group of self-reported normal hearing adult listeners. A total of 254 self-reported normal-hearing younger and older adults completed the SSQ and the APHAB questionnaire. The younger participants completed the questionnaires through Qualtrics, whereas the older participants completed the questionnaire through Qualtrics and a traditional pen-and-paper method. The younger listeners perceived a higher ability compared to the older adults in all the SSQ subscales (Speech, Spatial, and Qualities) and reported a lesser frequency of the problems in three of the four APHAB subscales (Ease of communication, Reverberation, and Background Noise). There was no significant difference in the frequency of the problems reported in the Aversiveness subscale. Self-reported normal-hearing listeners do not rate their listening ability at the top of the ability scale. Additionally, the large dataset presented here has a potential normative value for the SSQ and the APHAB questionnaires for self-reported normal-hearing adult listeners.

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

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.

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.

Neural responses to naturalistic audiovisual speech are related to listening demand in cochlear implant users

There is a weak relationship between clinical and self-reported speech perception outcomes in cochlear implant (CI) listeners. Such poor correspondence may be due to differences in clinical and “real-world” listening environments and stimuli. Speech in the real world is often accompanied by visual cues, background environmental noise, and is generally in a conversational context, all factors that could affect listening demand. Thus, our objectives were to determine if brain responses to naturalistic speech could index speech perception and listening demand in CI users. Accordingly, we recorded high-density electroencephalogram (EEG) while CI users listened/watched a naturalistic stimulus (i.e., the television show, “The Office”). We used continuous EEG to quantify “speech neural tracking” (i.e., TRFs, temporal response functions) to the show’s soundtrack and 8–12 Hz (alpha) brain rhythms commonly related to listening effort. Background noise at three different signal-to-noise ratios (SNRs), +5, +10, and +15 dB were presented to vary the difficulty of following the television show, mimicking a natural noisy environment. The task also included an audio-only (no video) condition. After each condition, participants subjectively rated listening demand and the degree of words and conversations they felt they understood. Fifteen CI users reported progressively higher degrees of listening demand and less words and conversation with increasing background noise. Listening demand and conversation understanding in the audio-only condition was comparable to that of the highest noise condition (+5 dB). Increasing background noise affected speech neural tracking at a group level, in addition to eliciting strong individual differences. Mixed effect modeling showed that listening demand and conversation understanding were correlated to early cortical speech tracking, such that high demand and low conversation understanding occurred with lower amplitude TRFs. In the high noise condition, greater listening demand was negatively correlated to parietal alpha power, where higher demand was related to lower alpha power. No significant correlations were observed between TRF/alpha and clinical speech perception scores. These results are similar to previous findings showing little relationship between clinical speech perception and quality-of-life in CI users. However, physiological responses to complex natural speech may provide an objective measure of aspects of quality-of-life measures like self-perceived listening demand.

Further Evidence for Individual Ear Consideration in Cochlear Implant Candidacy Evaluation

OBJECTIVE

To report speech outcomes after cochlear implantation (CI) for asymmetric hearing loss (AHL) and assess the influence of contralateral hearing.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

One hundred eighty-eight adults (mean age, 70 yr) undergoing CI for AHL from 2015 to 2020. Candidacy included pure-tone average (PTA) at least 70 dB hearing level and AzBio in quiet 60% or less in the implanted ear and AzBio in quiet greater than 40% in the contralateral ear.

MAIN OUTCOME MEASURES

PTA; Consonant-Nucleus-Consonant (CNC) word, AzBio sentences scores; Speech, Spatial, and Qualities of Hearing Scale (SSQ).

RESULTS

Mean preoperative PTA and AzBio in the implanted and contralateral ears were 85.2 and 68.1 dB hearing level and 24.7% and 69.2%, respectively. Mean CNC in the implanted ear increased from 18.3% preoperatively to 44.4% ( p < 0.0001) at 6 months and 49.3% ( p < 0.0001) at 12 months. Mean AzBio in the implanted ear improved from 24.7% preoperatively to 60.3% ( p < 0.0001) at 6 months and 64.3% ( p < 0.0001) at 12 months. Patients demonstrated significant improvement in all SSQ domains at 6 and 12 months. When comparing patients with preoperative contralateral AzBio greater than 60% versus 41% to 60%, no significant differences existed in postoperative CNC scores (6-mo: 47% versus 41%, p = 0.276; 12-mo: 51% versus 47%, p = 0.543). There were no significant differences in 6-month ( p = 0.936) or 12-month ( p = 0.792) CNC scores between patients with AHL (contralateral ear AzBio >40%) and 169 unilateral CI patients meeting the traditional Medicare criteria (contralateral ear AzBio ≤40%).

CONCLUSION

CI recipients with AHL derive significant speech improvements, supporting individual ear consideration for CI candidacy and patient benefit outside of current Medicare criteria.

Short- and Long-Term Effect of Cochlear Implantation on Disabling Tinnitus in Single-Sided Deafness Patients: A Systematic Review

Patients with single-sided deafness can experience an ipsilateral disabling tinnitus that has a major impact on individuals' social communication and quality of life. Cochlear implants appear to be superior to conventional treatments to alleviate tinnitus in single-sided deafness. We conducted a systematic review to evaluate the effectiveness of cochlear implants in single-sided deafness with disabling tinnitus when conventional treatments fail to alleviate tinnitus (PROSPERO ID: CRD42022353292). All published studies in PubMed/MEDLINE and SCOPUS databases until December 2021 were included. A total of 474 records were retrieved, 31 studies were included and were divided into two categories according to whether tinnitus was assessed as a primary complaint or not. In all studies, cochlear implantation, evaluated using subjective validated tools, succeeded in reducing tinnitus significantly. Objective evaluation tools were less likely to be used but showed similar results. A short-(3 months) and long-(up to 72 months) term tinnitus suppression was reported. When the cochlear implant is disactivated, complete residual tinnitus inhibition was reported to persist up to 24 h. The results followed a similar pattern in studies where tinnitus was assesed as a primary complaint or not. In conclusion, the present review confirmed the effectiveness of cochlear implantation in sustainably reducing disabling tinnitus in single-sided deafness patients.

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.

Longitudinal auditory data of children with prelingual single-sided deafness managed with early cochlear implantation

Individuals with single-sided deafness (SSD) have no access to binaural hearing, which limits their ability to localize sounds and understand speech in noisy environments. In addition, children with prelingual SSD are at risk for neurocognitive and academic difficulties. Early cochlear implantation may lead to improved hearing outcomes by restoring bilateral hearing. However, its longitudinal impact on the development of children with SSD remains unclear. In the current study, a group of young children with prelingual SSD received a cochlear implant at an early age. From the age of four, the children’s spatial hearing skills could be assessed using a spatial speech perception in noise test and a sound localization test. The results are compared to those of two control groups: children with SSD without a cochlear implant and children with bilateral normal hearing. Overall, the implanted group exhibited improved speech perception in noise abilities and better sound localization skills, compared to their non-implanted peers. On average, the children wore their device approximately nine hours a day. Given the large contribution of maturation to the development of spatial hearing skills, further follow-up is important to understand the long-term benefit of a cochlear implant for children with prelingual SSD.

Self-Rated Benefits of Auditory Performance after Bonebridge Implantation in Patients with Conductive or Mixed Hearing Loss, or Single-Sided Deafness

The Bonebridge implant can be a satisfactory solution for patients with conductive or mixed hearing loss (CHL or MHL), or with single-sided deafness (SSD). The aim of the study was to assess patients’ self-reported benefits with the Bonebridge and characterize the relationships between pre-implantation audiometric data, auditory functioning, and satisfaction after implantation. A focus was to see whether different types of hearing loss were associated with particular benefits. The study sample consisted of 81 patients. Procedures comprised pure tone audiometry before implantation, the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire, and a structured interview asking about satisfaction. Statistically significant improvements after implantation were found in all groups (CHL, MHL, SSD) on the APHAB questionnaire. In the structured interview, patients with SSD were the least satisfied. No significant correlation was found between pre-operative air-bone gap and bone conduction thresholds or with APHAB score. Bonebridge implantation is beneficial to patients with CHL or MHL, or with SSD. Assessment of patients for Bonebridge implantation is complex, and audiometric data should be complemented by patient-reported outcomes to provide deeper insight into their individual needs and attitudes.

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.

Impact of Reverberation on Speech Perception and Sound Localization Accuracy in Cochlear Implant Users With Single-Sided Deafness

OBJECTIVES

The aim of this study was to compare the impact of reverberation on sound localization accuracy and speech perception in noise between subjects with single-sided deafness using a cochlear implant (SSD-CI) and a normal-hearing control group.

METHODS

Nine SSD-CI subjects and 21 normal-hearing subjects participated in the study. In Experiment 1, the sound localization accuracy was measured with and without reverberation. In Experiment 2, speech reception thresholds were determined with four asymmetrically arranged noise sources in free-field and in reverberation. For the realization of reverberation, a room simulation system comprising of 128 loudspeakers was used.

RESULTS

No significant impact of reverberation was found on the sound localization accuracy of the SSD-CI subjects (free-field: 12.6°, reverberation: 11.9°), whereas the normal-hearing subjects performed significantly worse in reverberation (free-field: 1.8°, reverberation: 3.3°).Both subject groups experienced significantly deteriorated speech reception thresholds due to reverberation (pSSD-CI = 0.008, pNH < 0.001). Mean speech reception thresholds in the SSD-CI subjects were -9.7 dB SNR (free-field) and -4.2 dB SNR (reverberation) and a median individual decrease of 5.7 dB SNR in reverberation. Mean speech reception thresholds in the normal-hearing group were -14.0 dB SNR (free-field) and -10.3 dB SNR (reverberation).

CONCLUSION

A strong deterioration of sound localization accuracy due to reverberation did not occur. However, although partial restoration of binaural hearing is assumed in SSD-CI users, the impact of reverberation on speech perception in noise is much stronger compared to normal-hearing.

Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations.

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.

Benefits of Cochlear Implantation in Childhood Unilateral Hearing Loss (CUHL Trial)

Objectives/Hypotheses

Children with unilateral sensory hearing loss (UHL) struggle to understand speech in noise and locate the origin of sound and have reduced quality of hearing. This clinical trial will determine the benefits of cochlear implantation in children with UHL.

Study Design

Prospective clinical trial.

Methods

Twenty children with at least moderate to profound sensory hearing loss and poor speech perception (word score <30%) in one ear and normal hearing in the contralateral ear participated in a Food and Drug Administration‐approved clinical trial. Subjects were evaluated for speech perception in quiet, speech perception in noise, sound localization, and subjective benefits after implantation.

Results

CNC word score perception in quiet significantly improved (1% to 50%, P < .0001) by 12 months after activation. Speech perception in noise by BKB‐SIN significantly improved in all three noise configurations; there was a 3.6 dB advantage in head shadow (P < .0001), a 1.6 dB advantage in summation (P = .003), and a 2.5 dB advantage in squelch (P = .0001). Localization improved by 26° at 9 months (P < .0001). Speech, Spatial, and Qualities (SSQ) demonstrated significant improvements in speech (5.2 to 7.4, P = .0012), qualities of hearing (5.9 to 7.5, P = .0056), and spatial hearing (2.7 to 6.6, P < .0001). SSQ subscales associated with binaural hearing were significantly improved, as was listening effort (P = .0082). Subjects demonstrated a non‐significant improvement in fatigue.

Conclusions

This study demonstrates that children with UHL significantly benefit from cochlear implantation.

Level of Evidence

Level 3 Laryngoscope, 132:S1–S18, 2022

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.

Clinical characteristics of patients with unilateral auditory neuropathy

OBJECTIVE

To analyze the clinical characteristics of patients with unilateral auditory neuropathy (UAN), and to provide guidance for future clinical diagnosis and research.

METHODS

Patients who were clinically diagnosed with UAN from 2004 to 2019 were included. Clinical characteristics, audiological features, imaging findings, genetic test results and management effect were summarized and followed.

RESULTS

A total of 44 patients [mean age, 4.35 ± 4.39 years; 22 (50.00%) males and 22 (50.00%) females] were enrolled for analyses. Among the 38 patients who were tested by pure-tone or behavioral audiometry, the degree of hearing loss of the affected ear was characterized as mild in 2 ears (5.26%), moderate in 5 (13.16%), severe in 9 (23.68%) and profound in 22 (57.89%). For the 44 contralateral ears, 33 (75.00%) showed normal hearing and 11 (25.00%) presented with sensorineural hearing loss. Auditory brainstem responses were absent or abnormal in all 44 affected ears, while otoacoustic emissions and/or cochlear microphonics were present. Among the 18 patients who underwent magnetic resonance imaging (MRI), 7 (38.89%) presented cochlear nerve deficiency (CND). Nineteen candidate variants were found in 12 patients among the 15 UAN patients who were conducted targeted gene capture and next generation sequencing. Thirty patients were followed up by telephone to investigate their management effect.

CONCLUSIONS

Our study demonstrates comprehensive audiological features of patients with UAN to improve the clinical understanding and diagnosis. Some patients with UAN could show ipsilateral CND and MRI is essential to evaluate if the nerve is deficient. No pathogenic variants that directly related to the pathogenesis of UAN have been found in this study currently.

Effects of Head Movements on Sound-Source Localization in Single-Sided Deaf Patients With Their Cochlear Implant On Versus Off

OBJECTIVES

We investigated the ability of single-sided deaf listeners implanted with a cochlear implant (SSD-CI) to (1) determine the front-back and left-right location of sound sources presented from loudspeakers surrounding the listener and (2) use small head rotations to further improve their localization performance. The resulting behavioral data were used for further analyses investigating the value of so-called "monaural" spectral shape cues for front-back sound source localization.

DESIGN

Eight SSD-CI patients were tested with their cochlear implant (CI) on and off. Eight normal-hearing (NH) listeners, with one ear plugged during the experiment, and another group of eight NH listeners, with neither ear plugged, were also tested. Gaussian noises of 3-sec duration were band-pass filtered to 2-8 kHz and presented from 1 of 6 loudspeakers surrounding the listener, spaced 60° apart. Perceived sound source localization was tested under conditions where the patients faced forward with the head stationary, and under conditions where they rotated their heads between (Equation is included in full-text article.).

RESULTS

(1) Under stationary listener conditions, unilaterally-plugged NH listeners and SSD-CI listeners (with their CIs both on and off) were nearly at chance in determining the front-back location of high-frequency sound sources. (2) Allowing rotational head movements improved performance in both the front-back and left-right dimensions for all listeners. (3) For SSD-CI patients with their CI turned off, head rotations substantially reduced front-back reversals, and the combination of turning on the CI with head rotations led to near-perfect resolution of front-back sound source location. (4) Turning on the CI also improved left-right localization performance. (5) As expected, NH listeners with both ears unplugged localized to the correct front-back and left-right hemifields both with and without head movements.

CONCLUSIONS

Although SSD-CI listeners demonstrate a relatively poor ability to distinguish the front-back location of sound sources when their head is stationary, their performance is substantially improved with head movements. Most of this improvement occurs when the CI is off, suggesting that the NH ear does most of the "work" in this regard, though some additional gain is introduced with turning the CI on. During head turns, these listeners appear to primarily rely on comparing changes in head position to changes in monaural level cues produced by the direction-dependent attenuation of high-frequency sounds that result from acoustic head shadowing. In this way, SSD-CI listeners overcome limitations to the reliability of monaural spectral and level cues under stationary conditions. SSD-CI listeners may have learned, through chronic monaural experience before CI implantation, or with the relatively impoverished spatial cues provided by their CI-implanted ear, to exploit the monaural level cue. Unilaterally-plugged NH listeners were also able to use this cue during the experiment to realize approximately the same magnitude of benefit from head turns just minutes after plugging, though their performance was less accurate than that of the SSD-CI listeners, both with and without their CI turned on.

Psychometric properties for the Norwegian translations of two revised APHAB-subscales and an adapted IOI-HA (IOI-CI) in patients with cochlear implants

OBJECTIVE

The objective was to examine the psychometric properties of two questionnaires in Norwegian for the self-assessment of satisfaction following cochlear implantation.

DESIGN

The International Outcome Inventory for Hearing Aids adapted for cochlear implants (IOI-CI) and two revised subscales from the Norwegian translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) were applied. Internal consistency was tested using Cronbach's α. Testing of psychometric properties included the calculation of inter-item correlations and corrected item-total correlations. Spearman's rho was used to investigate associations. Exploratory principal component analyses with Kaiser normalisation were performed.

STUDY SAMPLE

One hundred and twenty-one patients (51 males) with cochlear implants (27-88 years, M = 59).

RESULTS

For IOI-CI, Cronbach's α was 0.79. Corrected item-total correlations ranged from 0.29 to 0.69. The factor analysis revealed two components. For APHAB, Cronbach's α was 0.91. Two components were revealed by the factor analysis. Corrected item-total correlations for the two subscales "communication in quiet situations" and "communication in adverse situations" were 0.47-0.81 and 0.58-0.80, respectively. The convergent validity of the questionnaires was adequate as reflected by a Spearman's coefficient of 0.67.

CONCLUSION

Both questionnaires show good psychometric properties.

Systematic Comparison of Trial Exclusion Criteria for Pupillometry Data Analysis in Individuals With Single-Sided Deafness and Normal Hearing

The measurement of pupil dilation has become a common way to assess listening effort. Pupillometry data are subject to artifacts, requiring highly contaminated data to be discarded from analysis. It is unknown how trial exclusion criteria impact experimental results. The present study examined the effect of a common exclusion criterion, percentage of blinks, on speech intelligibility and pupil dilation measures in 9 participants with single-sided deafness (SSD) and 20 participants with normal hearing. Participants listened to and repeated sentences in quiet or with speech maskers. Pupillometry trials were processed using three levels of blink exclusion criteria: 15%, 30%, and 45%. These percentages reflect a threshold for missing data points in a trial, where trials that exceed the threshold are excluded from analysis. Results indicated that pupil dilation was significantly greater and intelligibility was significantly lower in the masker compared with the quiet condition for both groups. Across-group comparisons revealed that speech intelligibility in the SSD group decreased significantly more than the normal hearing group from quiet to masker conditions, but the change in pupil dilation was similar for both groups. There was no effect of blink criteria on speech intelligibility or pupil dilation results for either group. However, the total percentage of blinks in the masker condition was significantly greater than in the quiet condition for the SSD group, which is consistent with previous studies that have found a relationship between blinking and task difficulty. This association should be carefully considered in future experiments using pupillometry to gauge listening effort.

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.

Systematic review of outcome domains and instruments used in designs of clinical trials for interventions that seek to restore bilateral and binaural hearing in adults with unilateral severe to profound sensorineural hearing loss ('single-sided deafness')

BACKGROUND

This systematic review aimed to identify, compare and contrast outcome domains and outcome instruments reported in studies investigating interventions that seek to restore bilateral (two-sided) and/or binaural (both ears) hearing in adults with single-sided deafness (SSD). Findings can inform the development of evidence-based guidance to facilitate design decisions for confirmatory trials.

METHODS

Records were identified by searching MEDLINE, EMBASE, PubMed, CINAHL, ClinicalTrials.gov, ISRCTN, CENTRAL, WHO ICTRP and the NIHR UK clinical trials gateway. The search included records published from 1946 to March 2020. Included studies were those as follows: (a) recruiting adults aged 18 years or older diagnosed with SSD of average threshold severity worse than 70 dB HL in the worse-hearing ear and normal (or near-normal) hearing in the better-hearing ear, (b) evaluating interventions to restore bilateral and/or binaural hearing and (c) enrolling those adults in a controlled trial, before-and-after study or cross-over study. Studies that fell just short of the participant eligibility criteria were included in a separate sensitivity analysis.

RESULTS

Ninety-six studies were included (72 full inclusion, 24 sensitivity analysis). For fully included studies, 37 exclusively evaluated interventions to re-establish bilateral hearing and 29 exclusively evaluated interventions to restore binaural hearing. Overall, 520 outcome domains were identified (350 primary and 170 secondary). Speech-related outcome domains were the most common (74% of studies), followed by spatial-related domains (60% of studies). A total of 344 unique outcome instruments were reported. Speech-related outcome domains were measured by 73 different instruments and spatial-related domains by 43 different instruments. There was considerable variability in duration of follow-up, ranging from acute (baseline) testing to 10 years after the intervention. The sensitivity analysis identified no additional outcome domains.

CONCLUSIONS

This review identified large variability in the reporting of outcome domains and instruments in studies evaluating the therapeutic benefits and harms of SSD interventions. Reports frequently omitted information on what domains the study intended to assess, and on what instruments were used to measure which domains.

TRIAL REGISTRATION

The systematic review protocol is registered on PROSPERO (International Prospective Register of Systematic Reviews): Registration Number CRD42018084274 . Registered on 13 March 2018, last revised on 7th of May 2019.

CI in single-sided deafness

The cochlear implant (CI) as a treatment option for single-sided deafness (SSD) started with a clinical study looking in to the influence of cochlear implantation with a MED-EL device on incapacitating unilateral tinnitus in SSD. The study began in 2003 and was conducted by P. Van de Heyning and his team in Antwerp, Belgium. The first CI in SSD without tinnitus in Germany was implanted by J. Mueller and R. Jacob in Koblenz in 2005. Translational research activities took place since then to evaluate the CI as a treatment option for SSD not only in adults but also in children. They assessed the hearing performance of SSD patients implanted with CI, importance of long electrode arrays in SSD patients, degree of acceptance of CI by SSD children, importance of early CI implantation in SSD children in developing language skills, music enjoyment by hearing with two ears and evidence on spiral ganglion cell body distribution. In 2013, MED-EL was the first CI manufacturer to receive the CE mark for the indication of SSD and asymmetric hearing loss (AHL) in adults and children. In 2019, MED-EL was the first CI manufacturer to get its CI device approved for patients over the age of five with SSD and AHL, by the FDA in the USA. This article covers the milestones of translational research from the first concept to the widespread clinical use of CI in SSD.

Cochlear Implants in Patients with Fluctuant or Progressive Hearing Loss on the Better Ear

Introduction  Cochlear implants have been proposed for cases of unilateral hearing loss, especially in patients with tinnitus impairment. Several studies have shown that they result in definite improvement of sound localization and speech understanding, both in quiet and noisy environments. On the other hand, there are few references regarding cochlear implants in patients whose better ears present hearing loss.

Objective  To report the audiological outcomes of three patients with unilateral deafness, in whom the better ears presented hearing losses, submitted to cochlear implants.

Methods  Three patients with unilateral profound hearing loss underwent a cochlear implant performed by the same surgeon.

Results  The patients' data are presented in detail.

Conclusion  The indications for cochlear implants are becoming more diverse with the expansion of clinical experience and the observation that they definitely help patients with special hearing problems.

Cochlear implant and tinnitus-a meta-analysis

Introduction

Tinnitus is a frequent symptom in cochlear implant patients, often reported as persistent and disabling in implant candidates. Tinnitus is rarely considered in the preoperative evaluation of patients who are eligible for cochlear implantation. Many studies have shown that a cochlear implant leads to a significant change in the perception of tinnitus.

Objective

To identify evidence in the scientific literature indicating that cochlear implant in eligible patients with tinnitus can improve tinnitus perception.

Methods

One hundred forty articles were found from nine databases, and 20 articles from the gray literature mentioned the relationship between cochlear implant and tinnitus perception in patients eligible for cochlear implant. The PICOS (population, intervention, comparison, and outcome) strategy, was used to define the eligibility criteria. The studies that met the inclusion criteria for this second step were included in a qualitative synthesis, and each type of study was analyzed using the Joanna Briggs Institute critical appraisal checklist for quasi-experimental studies and the Joanna Briggs Institute critical appraisal checklist for randomized clinical trials.

Results

The full texts of 11 articles were read, and 6 studies were selected for the meta-analysis. The total sample size in the evaluated articles was 136 patients with tinnitus who were eligible for cochlear implantation.

Conclusions

Taken together, these findings support the feasibility of cochlear implantation to reduce the perception of tinnitus, thus providing a new perspective in the treatment of tinnitus in patients with hearing loss who are candidates for cochlear implantation.

The effect of tinnitus on hearing-related quality of life outcomes in adult cochlear implant recipients

OBJECTIVE

To describe the effect of tinnitus distress on the hearing-related quality of life (QoL) outcomes over time in adult cochlear implant (CI) recipients.

DESIGN

A retrospective, longitudinal study of adult CI recipients was conducted. Hearing-related QoL and tinnitus distress were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Tinnitus Reaction Questionnaire (TRQ) preoperatively and at 6-months, 12-months and >24-month postoperatively. The association between tinnitus distress and hearing-related QoL outcomes over time was investigated. Furthermore, 13 potential predictive factors were identified from the retrospective dataset. Multiple regression analyses were performed to identify variables that influence hearing-related QoL outcomes over time.

STUDY SAMPLE

The study sample included 210 adult (≥18 years) CI recipients implanted between 2001 and 2017.

RESULTS

Lower tinnitus distress and younger age at implantation were significant predictors of better hearing-related QoL in adult CI recipients. A significant reduction in tinnitus distress up to two years post-implantation was found, as well as greater tinnitus distress correlating with poorer hearing-related QoL outcomes.

CONCLUSION

Tinnitus distress negatively affects the hearing-related QoL outcomes of adult CI recipients. Tinnitus distress and age at implantation were found to be significant predictors of hearing-related QoL when controlling for other predictive factors.

Development of cortical auditory responses to speech in noise in unilaterally deaf adults following cochlear implantation

BACKGROUND

For patients with single-sided deafness (SSD), restoration of binaural function via cochlear implant (CI) has been shown to improve speech understanding in noise. The objective of this study was to investigate changes in behavioral performance and cortical auditory responses following cochlear implantation.

DESIGN

Prospective longitudinal study.

SETTING

Tertiary referral center.

METHODS

Six adults with SSD were tested before and 12 months post-activation of the CI. Six normal hearing (NH) participants served as experimental controls. Speech understanding in noise was evaluated for various spatial conditions. Cortical auditory evoked potentials were recorded with /ba/ stimuli in quiet and in noise. Global field power and responses at Cz were analyzed.

RESULTS

Speech understanding in noise significantly improved with the CI when speech was presented to the CI ear and noise to the normal ear (p<0.05), but remained poorer than that of NH controls (p<0.05). N1 peak amplitude measure in noise significantly increased after CI activation (p<0.05), but remained lower than that of NH controls (p<0.05) at 12 months. After 12 months of CI experience, cortical responses in noise became more comparable between groups.

CONCLUSION

Binaural restoration in SSD patients via cochlear implantation improved speech performance noise and cortical responses. While behavioral performance and cortical auditory responses improved, SSD-CI outcomes remained poorer than that of NH controls in most cases, suggesting only partial restoration of binaural hearing.

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

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

MRI surveillance following concurrent cochlear implantation in cases of vestibular schwannoma resection

OBJECTIVE

Cochlear nerve preserving translabyrinthine vestibular schwannoma (VS) resection enables concurrent cochlear implantation. Implantation in patients with VS raises important concerns including the ability to undergo postoperative magnetic resonance imaging (MRI) monitoring of residual tumor growth or tumor recurrence, specifically with a retained magnet. We aim to assess the feasibility of MRI monitoring and the impact on image quality with retained cochlear implant (CI) magnets.

METHODS

Retrospective review of post-operative head MRI scans in CI recipients with a retained CI magnet, after cochlear nerve preserving translabyrinthine excision of VS. The ability to visualize the ipsilateral and contralateral internal auditory canal (IAC) and cerebellopontine angle (CPA) were assessed.

RESULTS

A total of eight surveillance head MRI were performed in six patients. In one case, in which the receiver was positioned lower, the view of the ipsilateral IAC and CPA was distorted. In all other cases, the views of both the ipsilateral and contralateral IAC and CPA were overall unimpaired.

DISCUSSION

Imaging artifact only very rarely impedes adequate visualization of the ipsilateral IAC or CPA in CI recipients. In anticipation of the need for further IAC and CPA imaging, it would be advisable to place the receiver in an exaggerated superior-posterior position to further decrease obscuring artifact. Thus, serial monitoring of VS tumors can be performed safely with preservation of image quality with a retained receiver magnet.

CONCLUSIONS

When placing the CI receiver-stimulator farther posterior-superiorly, excellent visualization of the IAC and CPA can be accomplished without significantly impairing the image quality.

Age Dependent Cost-Effectiveness of Cochlear Implantation in Adults. Is There an Age Related Cut-off?

OBJECTIVE

To analyze the impact of age at implantation on the cost-effectiveness of cochlear implantation (CI).

STUDY DESIGN

Cost-utility analysis in an adapted Markov model.

SETTING

Adults with profound postlingual hearing loss in a "high income" country.

INTERVENTION

Unilateral and sequential CI were compared with hearing aids (HA).

MAIN OUTCOME MEASURE

Incremental cost-effectiveness ratio (ICER), calculated as costs per quality adjusted life year (QALY) gained (in CHF/QALY), for individual age and sex combinations in relation to two different willingness to pay thresholds. 1 CHF (Swiss franc) is equivalent to 1.01 USD.

RESULTS

When a threshold of 50,000 CHF per QALY is applied, unilateral CI in comparison to HA is cost-effective up to an age of 91 for women and 89 for men. Sequential CI in comparison to HA is cost-effective up to an age of 87 for women and 85 for men. If a more contemporary threshold of 100,000 CHF per QALY is applied, sequential CI in comparison to unilateral CI is cost-effective up to an age of 80 for women and 78 for men.

CONCLUSIONS

Performing both sequential and unilateral CI is cost-effective up to very advanced ages when compared with hearing aids.

Subjective Benefits of Bimodal Listening in Cochlear Implant Recipients with Asymmetric Hearing Loss

OBJECTIVE

To investigate the influence of cochlear implant (CI) use on subjective benefits in quality of life in cases of asymmetric hearing loss (AHL).

STUDY DESIGN

Prospective clinical trial.

SETTING

Tertiary academic center.

SUBJECTS AND METHODS

Subjects included CI recipients with AHL (n = 20), defined as moderate-to-profound hearing loss in the affected ear and mild-to-moderate hearing loss in the contralateral ear. Quality of life was assessed with the Speech, Spatial, and Qualities of Hearing Scale (SSQ) pragmatic subscales, which assess binaural benefits. Subjective benefit on the pragmatic subscales was compared to word recognition in quiet and spatial hearing abilities (ie, masked sentence recognition and localization).

RESULTS

Subjects demonstrated an early, significant improvement (P < .01) in abilities with the CI as compared to preoperative abilities on the SSQ pragmatic subscales by the 1-month interval. Perceived abilities were either maintained or continued to improve over the study period. There were no significant correlations between results on the Speech in Quiet subscale and word recognition in quiet, the Speech in Speech Contexts subscale and masked sentence recognition, or the Localization subscale and sound field localization.

CONCLUSIONS

CI recipients with AHL report a significant improvement in quality of life as measured by the SSQ pragmatic subscales over preoperative abilities. Reported improvements are observed as early as 1 month postactivation, which likely reflect the binaural benefits of listening with bimodal stimulation (CI and contralateral hearing aid). The SSQ pragmatic subscales may provide a more in-depth insight into CI recipient experience as compared to behavioral sound field measures alone.

Low-Frequency Hearing Preservation With Long Electrode Arrays: Inclusion of Unaided Hearing Threshold Assessment in the Postoperative Test Battery

Purpose

The goal of this work was to evaluate the low-frequency hearing preservation of long electrode array cochlear implant (CI) recipients.

Method

Twenty-five participants presented with an unaided hearing threshold of ≤ 80 dB HL at 125 Hz pre-operatively in the ear to be implanted. Participants were implanted with a long (31.5-mm) electrode array. The unaided hearing threshold at 125 Hz was compared between the preoperative and postoperative intervals (i.e., initial CI activation, and 1, 3, 6, 9, and 12 months after activation).

Results

Eight participants maintained an unaided hearing threshold of ≤ 80 dB HL at 125 Hz postoperatively. The majority (n = 5) demonstrated aidable low-frequency hearing at initial activation, whereas 3 other participants experienced an improvement in unaided low-frequency hearing thresholds at subsequent intervals.

Conclusions

CI recipients can retain residual hearing sensitivity with fully inserted long electrode arrays, and low-frequency hearing thresholds may improve during the postoperative period. Therefore, unaided hearing thresholds obtained within the initial weeks after surgery may not reflect later hearing sensitivity. Routine measurement of postoperative unaided hearing thresholds—even for patients who did not demonstrate aidable hearing thresholds initially after cochlear implantation—will identify CI recipients who may benefit from electric–acoustic stimulation.

Supplemental Material

https://doi.org/10.23641/asha.11356637

What can we learn from adult cochlear implant recipients with single-sided deafness who became elective non-users?

Objective: This retrospective study investigates the incidence of elective cochlear implant (CI) non-use amongst a cohort of adult CI recipients with single-sided deafness (SSD), identifies the causes that led to non-use, and assesses how non-use could be prevented. Methods: All adults with SSD who received a CI between 2008 and 2018 and who became elective CI non-users were included. Elective non-users were defined as CI recipients who decided to stop using their CI or, if explantation was necessary, refused reimplantation. Results: 5/114 (4.4%) adults with SSD who received a CI became elective non-users. The 5 non-users were a mean 44.2 years old (range 33-70 years) at implantation, had a mean duration of deafness of 7.1 years (range 0.5-20 years) at implantation, and used their CI for a mean 11.5 months (range 1.5-60 months) before (fully) discontinuing use. The primary cause of elective non-use was postoperative discouragement due to unrealistic expectations (4 participants) regarding sound perception with the CI or about the greater than expected level of commitment necessary for rehabilitation. Conclusions: Elective non-use among adult CI recipients with single-sided deafness was very rare and could be further prevented by comprehensive counselling to ensure that candidates have realistic expectations about the rehabilitation requirements and the outcomes with the CI.