Cochlear Implantation in Adults With Asymmetric Hearing Loss: Speech Recognition in Quiet and in Noise, and Health Related Quality of Life

A Comprehensive Review of Auditory and Non-Auditory Effects of Noise on Human Health

OBJECTIVE

Excessive noise is unpleasant and induces several physiological and psychological effects. Noise pollution is a potential threat to humans, particularly those continuously exposed for extended periods throughout the day over many years. This review aims to examine the various auditory and non-auditory outcomes associated with prolonged exposure to noise pollution.

MATERIALS AND METHODS

The review utilized a combination of relevant keywords to search the electronic databases. After screening based on the applied selection criteria for title, abstract, and full text, 44 articles were finally selected for critical review.

RESULTS

We identified and analyzed research findings related to noise-induced hearing loss, tinnitus, and sleep disturbances along with non-auditory issues such as annoyance, cognitive impairments, and mental stress associated with cardiovascular disorders. Furthermore, the existing studies were compared and collated to highlight the unique challenges and significance of noise pollution as a distinctive environmental concern and to explore the ongoing efforts in its research and prevention, including the early detection and potential reversal of noise-induced hearing loss.

CONCLUSION

The fundamental health consequences of noise pollution underscore the need for extensive research encompassing emerging noise sources and technologies to establish a health management system tailored to address noise-related health concerns and reduce noise exposure risk among populations. Finally, further research is warranted to ensure improved measurement of noise exposure and related health outcomes, especially in the context of occupational noise.

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 However, clinical practice is variable, with some providers using outdated criteria and others exceeding current labeled indications.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.

Predictable Factors of People with Asymmetrical Hearing Loss Wearing a Hearing Aid in the Worse Ear Only

In patients with bilateral asymmetrical hearing loss (AHL), where only one hearing aid is available, it is difficult to decide which ear to amplify. The aim of this study was to evaluate the outcomes of hearing aid use for AHL patients fitted with a hearing aid in their worse ear only. One-hundred-two adults with asymmetrical-mixed or sensorineural hearing loss were retrospectively included. AHL was classified into three subgroups: unilateral hearing loss (UHL) and AHL type 1 (AHL1) and type 2 (AHL2). The main outcome measures were (1) the time spent wearing a hearing aid, (2) the hearing in a noise test (HINT), (3) the sound localization test and (4) the Korean version of the International Outcome Inventory for Hearing Aids (IOI-HA). The 1 kHz-hearing threshold of the better ear was significantly better in the successful users than in the intermittent users for UHL. Younger age was associated with significantly better outcomes than older for AHL1 and AHL2. Among the etiologies of AHL, sudden hearing loss was associated with significantly better outcomes of hearing aid use for AHL, UHL and AHL1 patients. In this study, the success rate and usage rates were 43.1% and 67.6% in AHL patients wearing a hearing aid in the worse ear. This study identified the hearing threshold of 1 kHz from the better ear, age and etiology of sudden hearing loss as audiometric and non-audiometric factors that affected the outcomes of hearing aid use.

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 implantation in patients with asymmetric hearing loss: reporting and discussing the benefits in speech perception, speech reception threshold, squelch abilities, and patients’ reported outcomes

Objectives

This study presents the results obtained in a group of patients with asymmetric hearing loss undergoing cochlear implantation at our institution. Prognostic factors are discussed in relation to different rehabilitative approaches for asymmetric hearing loss remediation. The current literature is also discussed.

Methods

Nineteen adult patients with post-verbal asymmetric hearing loss were enrolled. The results were assessed by means of a speech perception test, completed in silence and with background noise, and a speech reception threshold test (Oldenburg Sentence Test). The subjectively perceived benefits were assessed using the Speech, Spatial and Qualities of Hearing Scale.

Results

Statistically significant improvements were achieved by all patients in terms of speech perception and speech reception threshold, and in subjective benefits.

Conclusion

The results confirm the literature findings which suggest that patients with asymmetric hearing loss generally gain substantial benefit from cochlear implantation because of the binaural input, with significant improvement in speech perception abilities in noise, speech reception threshold, and squelch abilities.

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.

(Even Off-Label) Cochlear Implantation in Single-Sided Deafness and Asymmetric Hearing Loss Results in Measurable Objective and Subjective Benefit

OBJECTIVE

To quantify objective and subjective outcomes in cochlear implant (CI) recipients with asymmetric hearing loss, including single-sided deafness (SSD) whose candidacy was determined on an ear-specific basis when word recognition was 50% or less.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

BACKGROUND

The effectiveness of CI in cases of SSD and asymmetric hearing loss (AHL) has been described in terms of tinnitus suppression, improved speech recognition in quiet and noise, enhanced localization ability, and improved quality of life. However, CI is not yet routinely offered as a top option or standard of care for these individuals. Recent Food and Drug Administration (FDA) labeling limits aided word recognition in the ear to be implanted to only 5% in cases of AHL/SSD, which is significantly poorer than 40 to 50%, which is often referenced in cases of bilateral hearing loss. Anecdotal experience suggests that patients with much better preoperative word recognition than 5% can benefit from CI.

METHODS

We conducted a retrospective chart review of all adult CI candidates, with one ear exhibiting consonant-nucleus-consonant (CNC) word recognition scores at least 50% and one ear not meeting CI candidacy (i.e., CNC word recognition >50%). Outcome variables of interest included word and sentence recognition and subjective handicap questionnaires (hearing, tinnitus, dizziness) and the Speech Spatial Qualities questionnaire.

RESULTS

Statistically and clinically significant improvement in speech understanding (word, sentence, sentence in noise) was noted for both the SSD and AHL groups in the implanted ear. There were statistically and clinically significant subjective improvements noted for both groups on the Hearing Handicap Inventory, the Tinnitus Handicap Inventory, and the Speech Spatial Qualities questionnaire by 1 month after activation. There were no significant differences between the AHL and SSD groups on either objective or subjective measures of the implanted ear. Individual word understanding improved for the majority of recipients across both groups and is not dependent on meeting the FDA criteria of less than 5%.

CONCLUSIONS

Cochlear implantation is a viable option with measurable objective and perceived benefits for recipients with preoperative aided CNC word scores exceeding current FDA labeling. There is no significant difference between the AHL and SSD groups, suggesting that candidacy and outcome expectations should be set based on the ear to be implanted alone, without regard for the ability of the better hearing ear.

Cochlear Implant Evolving Indications: Our Outcomes in Adult Patients

Background: The eligibility criteria for cochlear implantation are constantly evolving, following the continuous progress in technology, knowledge about cochlear implant (CI) fitting, and the possibility to preserve residual hearing. Appropriate attention should be given to asymmetric hearing loss (AHL) and single-side deafness (SSD) subjects. This study aimed to analyze cochlear implant indications and evaluate the longitudinal performance outcomes for patients with different kinds and degrees of sensorineural hearing loss. Methods: A total of 69 adult hearing loss CI recipients were included and divided into four subgroups according to our CI indication criteria. We performed objective and subjective measures, including speech perception analysis in silence and with background noise, comparing the outcomes obtained in the four groups. Results: After cochlear implant surgery, concerning the preimplantation daily listening condition, a significantly improved speech perception score in silence and noise was found in all four groups (p < 0.05 for all). Conclusion: CI could represent an efficient solution for patients with AHL and SSD classes.

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.

MicroRNA Profiling in the Perilymph of Cochlear Implant Patients: Identifying Markers that Correlate to Audiological Outcomes

HYPOTHESIS

MicroRNA (miRNA) expression profiles from human perilymph correlate to post cochlear implantation (CI) hearing outcomes.

BACKGROUND

The high inter-individual variability in speech perception among cochlear implant recipients is still poorly understood. MiRNA expression in perilymph can be used to characterize the molecular processes underlying inner ear disease and to predict performance with a cochlear implant.

METHODS

Perilymph collected during CI from 17 patients was analyzed using microarrays. MiRNAs were identified and multivariable analysis using consonant-nucleus-consonant testing at 6 and 18 months post implant activation was performed. Variables analyzed included age, gender, preoperative pure tone average (PTA), and preoperative speech discrimination (word recognition [WR]). Gene ontology analysis was performed to identify potential functional implications of changes in the identified miRNAs.

RESULTS

Distinct miRNA profiles correlated to preoperative PTA and WR. Patients classified as poor performers showed downregulation of six miRNAs that potentially regulate pathways related to neuronal function and cell survival.

CONCLUSION

Individual miRNA profiles can be identified in microvolumes of perilymph. Distinct non-coding RNA expression profiles correlate to preoperative hearing and postoperative cochlear implant outcomes.

Use of Auditory Training and Its Influence on Early Cochlear Implant Outcomes in Adults

OBJECTIVE

Assess associations between postcochlear implant (CI) auditory training and early outcomes related to speech recognition and CI quality of life (CIQOL).

STUDY DESIGN

Longitudinal, prospective cohort.

SETTING

Tertiary academic center.

PATIENTS

Seventy-two adults undergoing cochlear implantation for bilateral severe-to-profound hearing loss.

INTERVENTIONS

Self-reported use of three categories of auditory training post-CI activation: (1) face-to-face training (e.g., speech pathologist), (2) passive home-based training (e.g., listening to audiobooks), and (3) computer-based training (e.g., interactive software).

MAIN OUTCOME MEASURES

Change in Consonant-Nucleus-Consonant phoneme (CNCp), CNC word (CNCw), AzBio sentences in quiet, and CIQOL-35 Profile global and domain scores from pre-CI to 3-month post-CI.

RESULTS

Of 72 patients, 52 (72.2%) used an auditory training resource. Of all patients, 18.4% used face-to-face training, 58.3% passive home-based training, and 33.3% computer-based training. At 3 months post-CI, use of any training was associated with greater improvement in speech recognition (d-range = 0.57-0.85) and global and domain-specific CIQOL scores, except entertainment (d-range = -0.33 to 0.77). Use of computer-based training demonstrated the greatest effect, with larger improvements in speech recognition (CNCp: d = 0.69[0.03,1.35]; CNCw: d = 0.80[0.14,1.46]; AzBio: d = 1.11[0.44,1.77]) and global and all domain-specific CIQOL scores (d-range = 0.05-1.35). Controlling for age, sex, household income, and use of multiple training resources, computer-based training remained the strongest positive predictor of speech recognition and CIQOL improvement, with significant associations with CNCp (ß = 33.07[1,43,64.719]), AzBio (ß = 33.03[5.71,60.35]), and CIQOL-global (ß = 10.92[1.15,20.70]) score improvement.

CONCLUSIONS

Our findings provide preliminary evidence-based recommendations for use of specific auditory training resources for new adult CI recipients. Auditory training, especially self-directed computer software, resulted in improved speech recognition and CIQOL outcomes after 3 months and are widely available for CI users.

Emotional Responses to Non-Speech Sounds for Hearing-aid and Bimodal Cochlear-Implant Listeners

The purpose of this project was to evaluate differences between groups and device configurations for emotional responses to non-speech sounds. Three groups of adults participated: 1) listeners with normal hearing with no history of device use, 2) hearing aid candidates with or without hearing aid experience, and 3) bimodal cochlear-implant listeners with at least 6 months of implant use. Participants (n = 18 in each group) rated valence and arousal of pleasant, neutral, and unpleasant non-speech sounds. Listeners with normal hearing rated sounds without hearing devices. Hearing aid candidates rated sounds while using one or two hearing aids. Bimodal cochlear-implant listeners rated sounds while using a hearing aid alone, a cochlear implant alone, or the hearing aid and cochlear implant simultaneously. Analysis revealed significant differences between groups in ratings of pleasant and unpleasant stimuli; ratings from hearing aid candidates and bimodal cochlear-implant listeners were less extreme (less pleasant and less unpleasant) than were ratings from listeners with normal hearing. Hearing aid candidates' ratings were similar with one and two hearing aids. Bimodal cochlear-implant listeners' ratings of valence were higher (more pleasant) in the configuration without a hearing aid (implant only) than in the two configurations with a hearing aid (alone or with an implant). These data support the need for further investigation into hearing device optimization to improve emotional responses to non-speech sounds for adults with hearing loss.

The impact of cochlear implantation on speech and language outcomes in children with asymmetric sensorineural hearing loss

INTRODUCTION

Cochlear implantation (CI) is considered in children with asymmetric sensorineural hearing loss (ASHL), or severe to profound sensorineural hearing loss in one ear, and better hearing contralaterally. The benefits of a CI in these children are not well established. This study investigated the impact of unilateral CI on speech and language outcomes in pediatric patients with ASHL.

METHODS

The retrospective chart review identified pediatric patients who underwent cochlear implantation for ASHL at a tertiary single center institution between 2014 and 2017. Children who underwent cochlear implantation in the poorer ear and maintained a hearing aid in the better ear were included, while children with cognitive impairment or prior cochlear nerve deficiency and auditory neuropathy were excluded. Speech and language measures were evaluated prior to implantation and at regular six-month intervals postoperatively. Ear specific Audiometry was evaluated at every visit and varied developmentally appropriate speech recognition tasks, including questionnaires, closed-set, and open-set measures, accounted for advancing childhood milestones. Specific measures of speech articulation, expressive and receptive language, and vocabulary were assessed including: Goldman Fristoe Test of Articulation (GFTA-3), Clinical Evaluation of Language Fundamentals (CELF-P2 or CELF-5), Receptive One-Word Picture Vocabulary Test (ROWPVT) and Expressive One Word Picture Vocabulary Test (EOWPVT). The mean difference and standard deviation of speech and language outcomes at preoperative and postoperative evaluations were calculated. The change in outcomes were further assessed over each post-operative time point.

RESULTS

Twenty-six children with asymmetric sensorineural hearing loss were included in the analysis, with 11 (42%) having bilateral enlarged vestibular aqueducts (EVA). At time of CI, unaided mean Pure Tone Average (PTA-4) for the better ear was 62Db HL, and worse ear was 92Db HL. There was an improvement in speech recognition in the implanted ear as expected. All preoperative speech and language evaluations were conducted within 7 months of cochlear implantation. Twenty-three patients had at least 1 postoperative re-evaluation. Fourteen children had preoperative and postoperative assessments with the same tool, with 13 patients (93%) showing improvement in at least 1 domain. For patients with repeated assessment within 12 months of surgery, we observed an average improvement in standard scores of: GFTA-3 (+11.2), CELF-P2 Core Language (+10.3), CELF-5 Core Language (+7.0), ROWPVT (+2.8) and EOWPVT (+4.5). Individual results are described.

CONCLUSION

Improvement in speech and language measures can be demonstrated in children undergoing unilateral cochlear implantation for asymmetric sensorineural hearing losses. These children, who are not typical CI candidates, can benefit from a CI in the poorer ear.

Cochlear Implantation in Vestibular Schwannoma: A Systematic Literature Review

Objective  Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review of hearing outcomes comparing neurofibromatosis 2 (NF2) and sporadic VS undergoing CI. A comparison of the two populations and predictor of outcome was assessed. This is an update to a previously presented study. Data Sources  Systemic data searches were performed in PubMed NCBI and Scopus by an academic librarian. No restrictions based on the year of publication were used. Study Selection  Studies were selected if patients had a diagnosis of NF2 and a CI placed in the affected side with reports of hearing outcome. Two independent reviewers screened each abstract and full-text article. Data Extraction  Studies were extracted at the patient level, and the assessment of quality and bias was evaluated according to the National Institutes of Health Quality Assessment Tool. Main Outcome Measures  Outcome predictors were determined by using the chi-square test and Student's t -test. Results  Overall, most CI recipients functioned in the high-to-intermediate performer category for both sporadic and NF2-related VS. Median AzBio (Arizona Biomedical Institute Sentence Test) was 72% (interquartile range [IQR]: 50) in NF2 patients and 70% (IQR: 7.25) in sporadic patients. Larger tumor size predicted a poorer final audiometric outcome. Conclusions  Categorization of hearing outcome into superior performance and inferior performance based on sentence recognition revealed a generally good hearing outcome regardless of treatment or patient population. Select patients with sporadic and NF2 VS may benefit from CI.

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.

Language and Audiological Outcomes Among Infants Implanted Before 9 and 12 Months of Age Versus Older Children: A Continuum of Benefit Associated With Cochlear Implantation at Successively Younger Ages

OBJECTIVE

To compare language and audiological outcomes among infants (<9 and <12 mo) and older children receiving cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

Pediatric patients receiving CI between October 1995 and October 2019.

INTERVENTION

Cochlear implantation.

MAIN OUTCOME MEASURES

Most recent language and audiological assessment scores were evaluated by age group.

RESULTS

A total of 118 children were studied, including 19 who were implanted <9 months of age, 19 implanted 9 to <12 months of age, and 80 implanted 12 to <36 months of age. The mean duration of follow-up was 7.4 ± 5.0 years. Most recent REEL-3 receptive (88 ± 12 vs. 73 ± 15; p = 0.020) and expressive (95 ± 13 vs. 79 ± 12; p = 0.013) communication scores were significantly higher in the <9 months group compared to the 9 to <12 months group. PLS and OWLS auditory comprehension and oral expression scores were significantly higher in the <12 months group compared to the 12 to <36 months group. The difference in NU-CHIPS scores between <12 and 12 to <36 months was statistically significant (89% ± 6 vs. 83% ± 12; p = 0.009). LNT scores differed significantly between <9 and 9 to <12 months (94% ± 4 vs. 86% ± 10; p = 0.028).

CONCLUSIONS

The recent FDA expansion of pediatric CI eligibility criteria to include infants as young as 9 months of age should not serve as a strict clinical cutoff. Rather, CI can be pursued in appropriately selected younger infants to optimize language and audiological outcomes.

Audiometric Profile of Cochlear Implant Recipients Demonstrates Need for Revising Insurance Coverage

OBJECTIVES/HYPOTHESIS

To describe the pre-implant audiometric profile of adult cochlear implant (CI) recipients to investigate whether current binaural candidacy requirements prevent access to patients who could benefit from CI.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective review from 2016 to 2018 evaluating preoperative pure-tone thresholds and speech perception scores in the ipsilateral and contralateral ear.

RESULTS

A total of 252 adult CI recipients undergoing 270 implants were identified. Median age at time of implantation was 70.5 years (IQR 61.3-78.3) for those undergoing unilateral implantation and 59.0 (IQR 48.0-72.3) for those undergoing bilateral implantation (P < .01). For unilateral implantation, median pre-implantation speech perception performance in the ear to be implanted was 8.0% (IQR 0%-26.0%) for CNC word scores, and 9.0% (IQR 0%-34.0%) for AzBio sentence scores in quiet. Median speech perception performance in the contralateral ear was 36.0% (IQR 14.0%-60.0%) on CNC word scores, and 48.5% (IQR 17.5%-76.0%) on AzBio sentence tests. Speech perception scores were significantly different between ears for word and sentence tests (P < .01). Patients older than age 65 were significantly less likely to undergo bilateral implantation (P = .03).

CONCLUSIONS

Adult CI recipients exhibit substantially poorer pre-implant speech perception scores than the commonly utilized ipsilateral qualifying threshold of 50% on sentence testing. Yet, existing insurance paradigms limit patients by excessively stringent binaural best-aided requirements. This limitation likely leads to worse device performance as patients often wait years for their binaural hearing to qualify while their ear to be implanted potentially experiences an unnecessarily extended duration of deafness. Older patients also experience a unique delay in referral for cochlear implantation.

LEVEL OF EVIDENCE

3- Retrospective review Laryngoscope, 131:E2007-E2012, 2021.

Bone Anchored Hearing Aids for the Treatment of Asymmetric Hearing Loss

OBJECTIVES

Asymmetric hearing loss is generally defined as a moderate-to-profound hearing loss in the poorer ear and a mild-to-moderate hearing loss in the better ear. Application of a bone conduction hearing aid is one of the possible treatments for the poorer ear in asymmetric hearing loss. However, the device essentially stimulates the contralateral better ear, precluding true binaural hearing. The aim of this paper is to evaluate the application and utility of bone-anchored hearing aids in the treatment of asymmetric hearing loss.

MATERIALS AND METHODS

We retrospectively evaluated 215 implanted subjects in our clinic and extracted a series of 27 patients affected by asymmetric hearing loss and treated with bone-anchored hearing aids. All 27 subjects had a mixed hearing loss after middle ear surgery. The preoperative and postoperative audiological data of these patients were collected and analyzed.

RESULTS

The audiological tests showed an improvement in the performance of hearing perception of sound and speech in quiet and noise. Moreover, the subjects have positively answered the questionnaires administered to evaluate subjective benefits. All subscales of the abbreviated profile of hearing aid benefit and speech, spatial, and qualities of hearing scale showed a significant improvement with the device.

CONCLUSION

Bone-anchored hearing aids are a suitable treatment for asymmetric hearing loss. When other devices cannot be utilized or are not indicated, the bone conduction devices may allow good audiological results.

The case for cochlear implantation in unilateral and asymmetric sensorineural hearing loss

PURPOSE OF REVIEW

Cochlear implants have been used to treat bilateral deafness for over 40 years. A more recent development has been the application of this technology toward single-sided deafness (SSD) and asymmetric hearing loss (AHL), culminating in the Food and Drug Administration (FDA) approval in the United States for this indication in July of 2019. This review examines the recent literature on cochlear implants for SSD and AHL, focusing on speech perception, sound localization, tinnitus, and quality of life.

RECENT FINDINGS

There is an expanding body of literature supporting the use of cochlear implant in SSD/AHL patients. The cochlear implant offers a unique rehabilitation option for this subset of patients as it potentially restores binaural hearing (direct stimulation of both ears). A review of the literature reveals significant improvements with the cochlear implant in speech perception in quiet and noise, sound localization, tinnitus, and quality of life. In addition, these improvements appear to be greater than what conventional options such as a contralateral routing of signal (CROS) hearing aid and bone conduction device (BCD) are able to achieve.

SUMMARY

Cochlear implants offer additional benefits over previously available options of CROS and BCDs and have recently been approved by the FDA for use in patient with SSD/AHL. Given the growing body of literature demonstrating the benefit of cochlear implant over other devices, it is important to offer cochlear implant as an option to these patients.

Speech discrimination impairment of the worse-hearing ear in asymmetric hearing loss

OBJECTIVE

This study aimed to compare the difference in maximum speech discrimination score (SDSmax) of the worse-hearing ear in asymmetric hearing loss (ASHL) patients with that in symmetric hearing loss (SHL) patients.

DESIGN

We retrospectively reviewed medical records of patients with suspected hearing loss (HL) who underwent audiometric examinations. Patients were divided into two groups according to the difference in air conduction (AC) threshold between the right and left ears: the SHL group and the ASHL group.

STUDY SAMPLE

Of the 102 patients (204 ears), 74 (148 ears) had SHL, and 28 had ASHL.

RESULTS

The worse-hearing ear of ASHL patients exhibited a statistically significantly higher AC threshold and lower SDSmax, compared with ears of SHL patients and better-hearing ears of ASHL patients, and SDSmax exhibited a statistically significant negative correlation with AC threshold. The SDSmax was statistically significantly lower in the worse-hearing ear of the ASHL group than in moderate to severe HL ears of the SHL group, even though these groups had comparable AC thresholds.

CONCLUSIONS

ASHL patients' worse-hearing ear exhibited a lower SDSmax than SHL patients' ears, despite a comparable AC threshold. Management of hearing impairment in ASHL patients should receive more attention.

Treating the Individual Ear in Children: Results of Cochlear Implantation in Children With Asymmetric Sensory Hearing Loss

OBJECTIVE

Determine speech outcomes of children undergoing cochlear implantation with severe-to-profound hearing loss in the implanted ear and moderate or better hearing loss in nonimplanted ear.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Forty-nine children with severe-to-profound hearing loss in the ear to be implanted (pure-tone average), and no worse than moderate hearing loss in the nonimplant ear.

INTERVENTION

Subjects underwent cochlear implantation from 2007 and 2017 in the ear with severe-to-profound hearing loss.

MAIN OUTCOME MEASURES

Consonant Nucleus Consonant or Phonetically Balanced Kindergarten word scores pre- and postoperatively were compared in both the implanted ear and binaural setting. Comparisons were made between Phonetically Balanced Kindergarten scores pre- and postoperatively or Consonant Nucleus Consonant scores pre- and postoperatively.

RESULTS

The average pure-tone average for the implant ear was 92 ± 13 dB HL and 55 ± 12 dB HL in the nonimplant ear. Word scores for the implant ear increased an average of 58 (±27) % following cochlear implantation at 12 months and 62 (±20) % at 24 months. Binaural best-aided word scores increased an average of 36 (±29) % at 12 months and 49 (±24) % at 24 months.

CONCLUSION

Children with asymmetric sensory hearing loss should have each ear treated individually as significant benefits can be gained not only in the implanted ear, but also in binaural hearing.

Speech Perception Changes in the Acoustically Aided, Nonimplanted Ear after Cochlear Implantation: A Multicenter Study

In recent years there has been an increasing percentage of cochlear implant (CI) users who have usable residual hearing in the contralateral, nonimplanted ear, typically aided by acoustic amplification. This raises the issue of the extent to which the signal presented through the cochlear implant may influence how listeners process information in the acoustically stimulated ear. This multicenter retrospective study examined pre- to postoperative changes in speech perception in the nonimplanted ear, the implanted ear, and both together. Results in the latter two conditions showed the expected increases, but speech perception in the nonimplanted ear showed a modest yet meaningful decrease that could not be completely explained by changes in unaided thresholds, hearing aid malfunction, or several other demographic variables. Decreases in speech perception in the nonimplanted ear were more likely in individuals who had better levels of speech perception in the implanted ear, and in those who had better speech perception in the implanted than in the nonimplanted ear. This raises the possibility that, in some cases, bimodal listeners may rely on the higher quality signal provided by the implant and may disregard or even neglect the input provided by the nonimplanted ear.

Better defining best-aided condition: The role of hearing aids on cochlear implantation qualification rates

OBJECTIVE

Describe the effect of hearing aid type used during cochlear implantation evaluation on qualification rates.

METHODS

Consecutive adult patients at an academic cochlear implant program undergoing cochlear implantation evaluation were identified to determine cochlear implantation qualification rate according to history of hearing aid use and type of hearing aid used during evaluation.

RESULTS

609 patients met criteria. 90.1% of patients reported prior use of a hearing aid, and 77.4% reported current use of a hearing aid. Patients were most likely to undergo cochlear implantation evaluation utilizing their own personal hearing aids exclusively (61.6%) followed by loaner hearing aids fitted at the time of the evaluation (28.2%). White patients were more likely to be tested using personal hearing aids (OR = 2.60, 95% CI 1.43 to 4.71). Married patients were more likely to be current hearing aid users (OR 1.62, 95% CI 1.04 to 2.51) and were more likely to be tested using personal hearing aids (OR = 1.68, 95% CI 1.10 to 2.56). Patients with a history of any hearing aid use (OR = 2.50, 95% CI 1.42 to 4.40) and current hearing aid use (OR = 1.62, 95% CI 1.06 to 2.49) were more likely to qualify for cochlear implantation. Patients tested using personal hearing aids were 1.5 times more likely to qualify for cochlear implantation (95% CI 0.99 to 2.27).

CONCLUSION

History of hearing amplification and current amplification predict cochlear implant qualification. Hearing aids fitted at the time of cochlear implantation evaluation may result in lower qualification rates.

Mechanisms of Localization and Speech Perception with Colocated and Spatially Separated Noise and Speech Maskers Under Single-Sided Deafness with a Cochlear Implant

OBJECTIVES

This study tested listeners with a cochlear implant (CI) in one ear and acoustic hearing in the other ear, to assess their ability to localize sound and to understand speech in collocated or spatially separated noise or speech maskers.

DESIGN

Eight CI listeners with contralateral acoustic hearing ranging from normal hearing to moderate sensorineural hearing loss were tested. Localization accuracy was measured in five of the listeners using stimuli that emphasized the separate contributions of interaural level differences (ILDs) and interaural time differences (ITD) in the temporal envelope and/or fine structure. Sentence recognition was tested in all eight CI listeners, using collocated and spatially separated speech-shaped Gaussian noise and two-talker babble. Performance was compared with that of age-matched normal-hearing listeners via loudspeakers or via headphones with vocoder simulations of CI processing.

RESULTS

Localization improved with the CI but only when high-frequency ILDs were available. Listeners experienced no additional benefit via ITDs in the stimulus envelope or fine structure using real or vocoder-simulated CIs. Speech recognition in two-talker babble improved with a CI in seven of the eight listeners when the target was located at the front and the babble was presented on the side of the acoustic-hearing ear, but otherwise showed little or no benefit of a CI.

CONCLUSION

Sound localization can be improved with a CI in cases of significant residual hearing in the contralateral ear, but only for sounds with high-frequency content, and only based on ILDs. In speech understanding, the CI contributed most when it was in the ear with the better signal to noise ratio with a speech masker.

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.

Musical Emotion Perception in Bimodal Patients: Relative Weighting of Musical Mode and Tempo Cues

Several cues are used to convey musical emotion, the two primary being musical mode and musical tempo. Specifically, major and minor modes tend to be associated with positive and negative valence, respectively, and songs at fast tempi have been associated with more positive valence compared to songs at slow tempi (Balkwill and Thompson, 1999; Webster and Weir, 2005). In Experiment I, we examined the relative weighting of musical tempo and musical mode among adult cochlear implant (CI) users combining electric and contralateral acoustic stimulation, or "bimodal" hearing. Our primary hypothesis was that bimodal listeners would utilize both tempo and mode cues in their musical emotion judgments in a manner similar to normal-hearing listeners. Our secondary hypothesis was that low-frequency (LF) spectral resolution in the non-implanted ear, as quantified via psychophysical tuning curves (PTCs) at 262 and 440 Hz, would be significantly correlated with degree of bimodal benefit for musical emotion perception. In Experiment II, we investigated across-channel spectral resolution using a spectral modulation detection (SMD) task and neural representation of temporal fine structure via the frequency following response (FFR) for a 170-ms /da/ stimulus. Results indicate that CI-alone performance was driven almost exclusively by tempo cues, whereas bimodal listening demonstrated use of both tempo and mode. Additionally, bimodal benefit for musical emotion perception may be correlated with spectral resolution in the non-implanted ear via SMD, as well as neural representation of F0 amplitude via FFR - though further study with a larger sample size is warranted. Thus, contralateral acoustic hearing can offer significant benefit for musical emotion perception, and the degree of benefit may be dependent upon spectral resolution of the non-implanted ear.

Bimodal Hearing or Bilateral Cochlear Implants? Ask the Patient

OBJECTIVE

The objectives of this study were to assess the effectiveness of various measures of speech understanding in distinguishing performance differences between adult bimodal and bilateral cochlear implant (CI) recipients and to provide a preliminary evidence-based tool guiding clinical decisions regarding bilateral CI candidacy.

DESIGN

This study used a multiple-baseline, cross-sectional design investigating speech recognition performance for 85 experienced adult CI recipients (49 bimodal, 36 bilateral). Speech recognition was assessed in a standard clinical test environment with a single loudspeaker using the minimum speech test battery for adult CI recipients as well as with an R-SPACE 8-loudspeaker, sound-simulation system. All participants were tested in three listening conditions for each measure including each ear alone as well as in the bilateral/bimodal condition. In addition, we asked each bimodal listener to provide a yes/no answer to the question, "Do you think you need a second CI?"

RESULTS

This study yielded three primary findings: (1) there were no significant differences between bimodal and bilateral CI performance or binaural summation on clinical measures of speech recognition, (2) an adaptive speech recognition task in the R-SPACE system revealed significant differences in performance and binaural summation between bimodal and bilateral CI users, with bilateral CI users achieving significantly better performance and greater summation, and (3) the patient's answer to the question, "Do you think you need a second CI?" held high sensitivity (100% hit rate) for identifying likely bilateral CI candidates and moderately high specificity (77% correct rejection rate) for correctly identifying listeners best suited with a bimodal hearing configuration.

CONCLUSIONS

Clinics cannot rely on current clinical measures of speech understanding, with a single loudspeaker, to determine bilateral CI candidacy for adult bimodal listeners nor to accurately document bilateral benefit relative to a previous bimodal hearing configuration. Speech recognition in a complex listening environment, such as R-SPACE, is a sensitive and appropriate measure for determining bilateral CI candidacy and also likely for documenting bilateral benefit relative to a previous bimodal configuration. In the absence of an available R-SPACE system, asking the patient whether or not s/he thinks s/he needs a second CI is a highly sensitive measure, which may prove clinically useful.

Hearing Preservation and Speech Outcomes After Cochlear Implantation in Meniere's Disease

OBJECTIVES/HYPOTHESIS

To evaluate speech perception outcomes and hearing preservation after cochlear implantation in patients with Meniere's disease (MD).

STUDY DESIGN

Retrospective chart review.

METHODS

Fifty-one adult patients, accounting for a total of 63 implants, with MD treated at a tertiary care center were included in the study. Patients with unaided preoperative air-conduction thresholds ≤80 dB at 250 Hz were included in hearing preservation analyses. The primary outcome measure was Consonant-Nucleus-Consonant (CNC) score. Hearing preservation was assessed as follows: 1) maintenance of functional hearing, defined as a postoperative unaided air-conduction threshold ≤80 dB at 250 Hz and 2) low-frequency pure-tone average (LFPTA) shift.

RESULTS

Speech perception scores improved significantly postimplantation; specifically, the CNC mean score was 9% preoperatively and increased to 57% by 1 year postoperatively (P < .001). Eighteen ears were included in hearing preservation analysis; the mean preoperative LFPTA was 65 dB (standard deviation [SD] = 10). The mean postoperative LFPTA at activation was 93 dB (SD = 21), and at 1 year was 102 dB (SD = 11). Twenty-seven percent of patients achieved short-term functional hearing preservation, whereas the longer-term outcomes were less favorable (11%).

CONCLUSIONS

Speech perception scores improve after implantation in patients with MD. Hearing preservation is possible in patients with MD, albeit at lower rates than reported non-MD populations. Our data suggest that there can be degradation in acoustic hearing over time.

LEVEL OF EVIDENCE

4 Laryngoscope, 2019.