Determining Cochlear Implant Candidacy in Adults: Limitations, Expansions, and Opportunities for Improvement

Sensitivity and Specificity of Intraoperative TransImpedance Matrix Recordings Compared With X-ray Imaging in Detecting Perimodiolar Cochlear Implant Tip Foldovers: A Multicenter Study

OBJECTIVE

Characterize the sensitivity and specificity of TransImpedance Matrix (TIM) recordings compared with x-rays in detecting cochlear implant tip foldovers.

STUDY DESIGN

Retrospective.

SETTING

Multi-institutional, academic and private surgery centers.

PATIENTS

Patients 6 months and older undergoing cochlear implantation.

INTERVENTIONS

After cochlear implant array insertion, intraoperative TIM recordings and x-rays were conducted to confirm appropriate placement. If a foldover was identified, repeat insertion, followed by TIM and x-ray, was performed.

MAIN OUTCOME MEASURES

Presence of tip foldovers as determined by TIM recordings and x-rays.

RESULTS

There were 13 tip foldovers out of 484 insertions, yielding a 2.7% tip foldover rate. Using x-rays as the "gold standard," TIM recordings showed 100% sensitivity, 99.6% specificity, 84.6% positive predictive value (PPV), and 100% negative predicative value in detecting tip foldovers. The x-ray images for two TIM-identified tip foldovers were interpreted as normal intraoperatively (apparent false positives), but then were interpreted as foldovers when presented to the operating surgeon postoperatively in a blinded fashion. If these false positives had been reclassified as true positives, TIM specificity and PPV would both improve to 100%.

CONCLUSIONS

These results provide further support regarding the utility of TIM recordings to evaluate appropriate cochlear implant electrode array position. Despite the low tip foldover rate reported across the literature and within this study, this multicenter patient group provided a large sample size to calculate the sensitivity and specificity of TIM recordings in identifying tip foldovers. Compared with the reference-standard, x-ray imaging, TIM recordings show equivalent, and in some cases superior, performance in identification of tip foldovers. Thus, use of TIM can potentially preclude the need for routine intraoperative x-rays without compromising patient care.

Speech Outcomes of Cochlear Implantation, from 1983 to Present: A Systematic Review

OBJECTIVE

We sought to assess whether the totality of advancements seen in cochlear implant (CI) design and implementation have translated to significant improvements in speech perception scores.

DATABASES REVIEWED

EMBASE, PubMed/MEDLINE, and the Cochrane Central Register of Controlled Trials.

METHODS

A systematic review of all English-language studies in peer-reviewed journals from 1946 to August 2022 was performed based on the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were of adult patients who underwent cochlear implantation with Cochlear®, Med-EL, or Advanced Bionics devices with 12 months postoperative sentence recognition testing results. Meta-regression was performed to assess the relationship between speech recognition score and year of implantation. Preimplantation score and unilateral versus bilateral implantation were adjusted for. Subgroup analysis was performed by restricting to studies of <5 years duration and in which outcomes were measured ≤12 months postoperatively to reduce the likelihood of patients with remotely implanted devices having undergone upgrades to more contemporary coding software.

RESULTS

A total of 37 studies met criteria for inclusion, representing CIs implanted between 1983 and 2019. No significant association was identified between median study year and scores on 12-month postoperative sentence recognition testing on any of AzBio in quiet, CNC words, or HINT sentences in quiet. Subgroup analysis showed no difference in outcomes across 15 studies including patients implanted from 2007 to 2019.

CONCLUSION

In the absence of improved CI coding strategies since 2007, speech recognition outcomes in quiet have also not improved significantly since this time.

Clinical Outcomes for Adult Single-Sided Deafness Cochlear Implantees Exceeding the 5% Candidacy Criterion

OBJECTIVES

While single-sided deafness cochlear implants (SSD-CIs) have now received regulatory approval in the United States, candidate-ear candidacy criteria (no better than 5% word-recognition score) are stricter than for traditional CI candidates (50 to 60% speech recognition, best-aided condition). SSD implantation in our center began before regulatory approval, using a criterion derived from traditional candidacy: 50% consonant-nucleus-consonant (CNC) word-identification score in the candidate ear. A retrospective analysis investigated whether SSD patients exceeding the 5% CNC criterion nevertheless benefitted from a CI as assessed by spatial-hearing tests (speech understanding in noise [SIN] and localization) and by a patient-reported outcome measure quality-of-life instrument validated for patients with CIs.

DESIGN

A retrospective chart review assessed the clinical experience of a single CI center. Subjects consisted of 27 adult CI recipients with SSD (N = 21) or asymmetric hearing loss (AHL; N = 6) implanted since September 2019 with at least 3 months of postoperative follow-up. Patients with revision surgery or simultaneous labyrinthectomy and CI surgery were excluded from the sample. Subjects were divided into 2 groups based on preoperative CNC scores measured under best-aided conditions with a behind-the-ear hearing aid in the sound field at 0.9 m from a front loudspeaker, and the better ear masked using an insert earphone with 45 dB HL speech-weighted noise. The "MEETS" group had preoperative CNC word scores <5%; the "EXCEEDS" group had scores >5%. The clinical protocol also included intelligibility tests using AzBio sentences in the same test conditions as CNC; binaural spatial testing (broadband-noise sound localization, and matrix-sentence speech-reception thresholds in spatially separated noise) using a custom-built 7-speaker array; and the CI Quality of Life (CIQOL) instrument. To evaluate CI benefit, preoperative unaided performance was compared with postoperative binaural (acoustic ear + CI ear) performance at a clinic visit closest to 6 months postsurgery.

RESULTS

Of 27 SSD-CI recipients, 11 subjects exceeded the 5% preoperative CNC candidacy criterion. Both the MEETS and EXCEEDS groups improved significantly on all 5 primary study outcome measures (CI-alone CNC and AzBio, binaural SIN and sound localization, and CIQOL). The only statistically significant differences observed between the MEETS and EXCEEDS groups were that preoperative CNC and AzBio scores were significantly higher for the EXCEEDS group, as expected given that the groups were defined based on preoperative speech-perception scores in quiet. There were no statistically significant differences between the MEETS and EXCEEDS groups in postoperative scores in any test or in the magnitude of the improvement from preoperative to postoperative assessment.

CONCLUSIONS

SSD- and AHL-CI recipients exceeding the 5% CNC preoperative candidacy criterion significantly improved in CI-alone speech perception, spatial hearing, and subjectively reported CIQOL outcomes and the observed benefits were indistinguishable from SSD- and AHL-CI recipients who met the 5% criterion. A less-restrictive SSD-CI and AHL-CI candidacy criterion should be considered, and larger-scale clinical trials to evaluate CI efficacy using a less-stringent candidate-ear criterion are warranted.

Qualifying Cochlear Implant Candidates-Does it Matter How Patients Are Qualified?

OBJECTIVE

Evaluate variable qualification criteria for cochlear implant (CI) recipients and 12-month speech perception outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING

HERMES national database and nonoverlapping single-institution CI database.

PATIENTS

A total of 2,124 adult unilateral CI recipients categorized by qualifying status: AzBio in quiet (n = 1,239), +10 dB SNR (but not in quiet; n = 519), +5 dB SNR (but not in quiet or +10 dB SNR; n = 366); CNC ≤40% (n = 1,037), CNC 41% to 50% (n = 31), and CNC 51% to 60% (n = 20).

INTERVENTIONS

CI.

MAIN OUTCOME MEASURES

Pre- and 12-month postoperative speech perception performance. Clinically significant improvement was defined as ≥15% gain.

RESULTS

Quiet qualifiers experienced improvement in all listening conditions, whereas +10 dB SNR and +5 dB SNR qualifiers only improved in their qualifying condition and implanted ear CNC. When stratified by expanded Medicare criteria (binaural AzBio ≤60% correct), patients that qualified in quiet experienced improvements regardless of qualifying threshold or background noise. However, those that qualified in noise and AzBio ≤60% experienced mixed results in quiet and limited gain in background noise. When ≤60% criteria was applied to CNC of the worse ear, ≤40% qualifiers experienced large improvements in all tested conditions, but those who qualified by 41% to 50% or 51% to 60% only demonstrated modest improvements in AzBio sentence testing.

CONCLUSIONS

Quiet qualifiers improved in all testing conditions, while those qualifying in noise improved in their qualifying condition. Patients who qualified by expanded Medicare criteria (≤60%) showed improvement when qualifying with AzBio in quiet, but should be used with caution when qualifying patients in background noise or CNC due to more limited gains in performance.

What Do People Want to Know About Cochlear Implants: A Google Analytic Study

OBJECTIVE

Identify the questions most frequently asked online about cochlear implants (CI) and assess the readability and quality of the content.

METHODS

A Google search engine observational study was conducted via a search response optimization (SEO) tool. The SEO tool listed the questions generated by Google's "People Also Ask" (PAA) feature for the search queries "cochlear implant" and "cochlear implant surgery." The top 50 PAA questions for each query were conceptually classified. Sourced websites were evaluated for readability, transparency and information quality, and ability to answer the question. Readability and accuracy in answering questions were also compared to the responses from ChatGPT 3.5.

RESULTS

The PAA questions were commonly related to technical details (21%), surgical factors (18%), and postoperative experiences (12%). Sourced websites mainly were from academic institutions, followed by commercial companies. Among all types of websites, readability, on average, did not meet the recommended standard for health-related patient education materials. Only two websites were at or below the 8th-grade level. Responses by ChatGPT had significantly poorer readability compared to the websites (p < 0.001). These online resources were not significantly different in the percentage of accurately answering the questions (websites: 78%, ChatGPT: 85%, p = 0.136).

CONCLUSIONS

The most searched topics were technical details about devices, surgical factors, and the postoperative experience. Unfortunately, most websites did not meet the ideal criteria of readability, quality, and credibility for patient education. These results highlight potential knowledge gaps for patients, deficits in current online education materials, and possible tools to better support CI candidate decision-making.

LEVEL OF EVIDENCE

NA Laryngoscope, 135:840-847, 2025.

Impact of Perioperative Anticoagulation and Antiplatelet Therapy on Hearing Preservation Outcomes

OBJECTIVE

To report hearing preservation (HP) outcomes based on anticoagulation/antiplatelet use (blood thinner, BT) following cochlear implantation (CI).

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary referral center.

PATIENTS

Three hundred twenty-six adults (361 ears: no BT = 210, BT held = 86, BT continued = 65) implanted between 2012 and 2021 with preoperative low-frequency pure-tone average (LFPTA) of 65 dB HL or better.

MAIN OUTCOME MEASURE

Postoperative HP, defined as LFPTA ≤80 dB HL, at 1, 3, 6, and 12 months.

RESULTS

Compared to no BT, the BT held and continued groups were older (60.6 vs 72.7 vs 73.0 yrs, p < 0.001) and had diabetes (10% vs 28% vs 22%, p < 0.001). Electrode type, steroid use, surgical approach, and preoperative LFPTA were equivalent among groups. Postoperative HP rates were significantly higher for no BT than the BT held and continued groups at 1 month (62% vs 48% vs 43%, p = 0.008), with equivalent results at 3, 6, and 12 months. When patients were stratified by BT type, there were no significant differences in HP outcomes. On multivariate analysis, BT status was not a significant predictor of HP rates at 1 or 12 months. Younger age (OR 0.95, 95% CI 0.94-0.97, p < 0.001) was the only significant predictor of 1- but not 12-month HP.

CONCLUSIONS

BT use, regardless of whether held for surgery, was associated with inferior early HP outcomes. After controlling for age, BT status was not a significant predictor of HP, suggesting inherently poorer cochlear health in patients who are on BTs.

Individual control of input rate improves recall of spoken discourse by adult users of cochlear implants: An exploratory study

Although cochlear implants (CI) successfully replace the sense of hearing, they do not restore natural hearing. Still, CI users adapt to this novel signal, reaching meaningful levels of speech recognition in clinical tests that focus on repetition of words and short sentences. However, many patients who score above average in clinical speech perception tests complain that everyday speech interactions are both difficult and cognitively draining. In part, this difficulty may be due to the naturally rapid pace of everyday discourse. We report a study in which 12 CI users aged 23 to 77, recalled multi-sentence discourse presented without interruption, or in the condition of interest, when passages were paused at major linguistic boundaries, with participants given control of when to initiate the next segment. Comprehension of the discourse structure was based on a formalised representational system that organises discourse elements hierarchically to index the relative importance of different elements to the overall understanding of the discourse. Results showed (a) better recall when CI users were allowed to control the discourse pace; (b) an overall effect of aging, with older CI users recalling discourse less accurately; (c) better recall for passages with higher average inter-word predictability; (d) a "semantic hierarchy effect" reflected by better recall of main ideas versus minor details; (e) an attenuation of the semantic hierarchy effect for low predictability passages. Results underscore the benefits of extra processing time in addressing CI listening challenges and highlight the limited ecological validity of single-word or single-sentence speech recognition tests.

Cochlear Implant Infections

Cochlear implants (CIs) are associated with a range of infections. These infections present unique considerations because of their position relative to the respiratory tract and the central nervous system, as well as the propensity for biofilms to form on CIs. This article reviews infections related to CIs, including otitis media, mastoiditis, meningitis, and deep CI infection. High-quality evidence on the prevention and management of CI infections is lacking; however, best practices regarding prevention and management are provided.

Sensory-substitution based sound perception using a spinal computer-brain interface

Sensory substitution offers a promising approach to restore lost sensory functions. Here we show that spinal cord stimulation (SCS), typically used for chronic pain management, can potentially serve as a novel auditory sensory substitution device. We recruited 13 patients undergoing SCS implantation and translated everyday sound samples into personalized SCS patterns during their trial phase. In a sound identification task-where chance-level performance was 33.3%-participants ( n = 8 ) achieved a mean accuracy of 72.8% using only SCS input. We observed a weak positive correlation between stimulation bitrate and identification accuracy. A follow-up discrimination task ( n = 5 ) confirmed that reduced bitrates significantly impaired participants' ability to distinguish between consecutive SCS patterns, indicating effective processing of additional information at higher bitrates. These findings demonstrate the feasibility of using existing SCS technology to create a novel neural interface for a sound prosthesis. Our results pave the way for future research to enhance stimulation fidelity, assess long-term training effects, and explore integration with other auditory aids for comprehensive hearing rehabilitation.

Preliminary Validation of Hearing Device-Related Stigma Measures in Four United States Populations

OBJECTIVES

Although hearing devices such as cochlear implants and hearing aids often improve communication, many people who are d/Deaf or hard of hearing (d/DHH) choose not to use them. Hearing device-related stigma, or negative societal beliefs about people who use hearing devices, often drives this decision. Although much research has documented the negative effects of hearing device-related stigma, no widely accepted, validated measure to quantify such stigma across populations currently exists. In this article, we describe the preliminary validation of four distinct but related scales measuring hearing device-related stigma in different populations, including people who use hearing devices and those close to them.

DESIGN

We preliminarily validated four measures for quantifying hearing device-related stigma in different populations that were previously developed and refined through a literature review, Delphi interviews, cognitive interviews, and a pretest. We preliminarily validated these measures through self-administered online surveys in a convenience sample in the United States. Among participants who use a hearing device and who either (a) self-identified as being d/DHH before they developed language (lifelong; n = 78) or (b) those who self-identified as having acquired a d/DHH identity after they developed language (acquired n = 71), we validated an anticipated hearing device-related stigma scale (d/DHHS-LE-HDA). We validated three scales that measure perceived hearing device-related stigma observed by parents of children who are d/DHH and who use a hearing device (n = 79) (d/DHHS-P-HDPO), care partners of adults who are d/DHH and use a hearing device (n = 108) (d/DHHS-CP-HDPO), and health care providers (n = 203) (d/DHHS-HCP-HDSH). Exploratory factor analysis assessed the reliability of each measure.

RESULTS

Each of the four scales loaded onto one factor. Factor loadings for the eight-item scale measuring anticipated hearing device-related stigma among the two populations with lived experience ranged from 0.635 to 0.910, with an ordinal α of 0.93 in the lifelong d/DHH participants and 0.94 among the acquired d/DHH participants. The six-item scale of perceived stigma observed by parents had item loadings from 0.630 to 0.920 (α = 0.91). The nine-item scale of hearing device-related stigma observed by care partners had item loadings from 0.554 to 0.922 (α = 0.95). The eight-item scale of hearing device-related stigma reported by health care providers had item loadings from 0.647 to 0.941 (α = 0.89).

CONCLUSIONS

Preliminary validation results show that the four stigma measures perform well in their respective populations. The anticipated stigma scale performed similarly well for both lifelong d/DHH and acquired d/DHH, which suggests that it could perform well in different contexts. Future research should further validate the scales described here as well as measure hearing device-related stigma in different populations-including people who live in different geographic regions and people using different kinds of hearing devices-and evaluate the success of interventions developed to reduce hearing device-related stigma.

On the Design, Fabrication, and Characterization of a Novel Thin-Film Electrode Array for Use in Cochlear Implants

Thin-film electrode arrays (TFEAs) have been developed as an alternative to conventional electrode arrays (CEAs) used in cochlear implants. However, TFEAs produced by microfabrication techniques have not yet been used clinically because their structural and mechanical properties are far from those of CEAs. The aim of this study is to design, fabricate, and investigate the mechanical and tribological behavior and evaluate the performance of different TFEA designs. Finite Element Analysis (FEA) is performed to determine the elastic properties of several designs. A custom-build experimental setup is designed to observe the tribological behavior in different speeds and environments where frictional (lateral) and vertical force (normal force) are measured on a flat surface and within artificial cochlea. According to the FEA results, the maximum stiffness of the CEA is 37.93 mN/mm and 0.363 mN/mm and TFEA-4 has a maximum stiffness of 39.08 mN/mm and 0.306 mN/mm in the longitudinal and transverse axes, respectively. It is shown experimentally that adding a dummy wire to the carrier of the EA enhances both its longitudinal and transverse stiffness, thereby postponing the initiation of dynamic sliding due to the elevated buckling limit. It is also revealed that the type of TFEA support structure affects both normal and frictional forces, as well as the coefficient of friction.

Hebrew Digits in Noise (DIN) Test in Cochlear Implant Users and Normal Hearing Listeners

This study aimed to compare the Hebrew version of the digits-in-noise (DIN) thresholds among cochlear implant (CI) users and their normal-hearing (NH) counterparts, explore the influence of age on these thresholds, examine the effects of early auditory exposure versus its absence on DIN threshold, and assess the correlation between DIN thresholds and other speech perception tests. A total of 13 children with CI (aged 5.5-11 years), 15 pre-lingual CI users (aged 14-30 years), and 15 post-lingual CI users (aged 22-77 years), and their age-matched NH controls (n = 45) participated in the study. Speech perception tasks, including the DIN test, one-syllable word test, and sentence identification tasks in various auditory conditions, served as the main outcome measures. The results indicated that CI users exhibited higher speech reception thresholds in noise across all age groups compared to NH peers, with no significant difference between pre-lingual and post-lingual CI users. Significant differences were also observed in monosyllabic word and sentence accuracy in both quiet and noise conditions between CI and NH groups. Furthermore, correlations were observed between the DIN and other speech perception tests. The study concludes that CI users require a notably higher signal-to-noise ratio to discern digits in noise, underscoring the DIN test's utility in assessing speech recognition capabilities in CI users while emphasizing the need for a comprehensive test battery to fully gauge their speech perception abilities.

Cochlear implant electrode design for safe and effective treatment

The optimal placement of a cochlear implant (CI) electrode inside the scala tympani compartment to create an effective electrode-neural interface is the base for a successful CI treatment. The characteristics of an effective electrode design include (a) electrode matching every possible variation in the inner ear size, shape, and anatomy, (b) electrically covering most of the neuronal elements, and (c) preserving intra-cochlear structures, even in non-hearing preservation surgeries. Flexible electrode arrays of various lengths are required to reach an angular insertion depth of 680° to which neuronal cell bodies are angularly distributed and to minimize the rate of electrode scalar deviation. At the time of writing this article, the current scientific evidence indicates that straight lateral wall electrode outperforms perimodiolar electrode by preventing electrode tip fold-over and scalar deviation. Most of the available literature on electrode insertion depth and hearing outcomes supports the practice of physically placing an electrode to cover both the basal and middle turns of the cochlea. This is only achievable with longer straight lateral wall electrodes as single-sized and pre-shaped perimodiolar electrodes have limitations in reaching beyond the basal turn of the cochlea and in offering consistent modiolar hugging placement in every cochlea. For malformed inner ear anatomies that lack a central modiolar trunk, the perimodiolar electrode is not an effective electrode choice. Most of the literature has failed to demonstrate superiority in hearing outcomes when comparing perimodiolar electrodes with straight lateral wall electrodes from single CI manufacturers. In summary, flexible and straight lateral wall electrode type is reported to be gentle to intra-cochlear structures and has the potential to electrically stimulate most of the neuronal elements, which are necessary in bringing full benefit of the CI device to recipients.

Understanding Patient Utilization Patterns of Cochlear Implant Processors

OBJECTIVE

To evaluate the extent of benefit the second processor provides and to better understand utilization patterns regarding cochlear implant (CI) sound processors.

BACKGROUND

Institutional contracts determine the external CI sound processor hardware that a patient is eligible for. Despite the high prevalence of CI worldwide, there is a paucity in the literature regarding patient preferences and how patients utilize provided external hardware.

METHODS

A close-ended, multiple-choice survey was mailed to all patients over the age of 18 years who underwent CI between 2016 to 2020 at a tertiary academic medical center. Patients who received their CI hardware prior to 2018 were provided 2 processors, whereas those who received their hardware in 2018 or later were provided 1 processor.

RESULTS

A total of 100/263 surveys were returned for a response rate of 38.0%. Of the cohort with 1 processor, 31.3% experienced a period without a functioning processor and access to sound compared to 5.6% of the cohort with 2 processors (P = -.003). Of the cohort with 2 processors, 24.3% noted that they often or always utilize their second processor. When asked how important having a second processor was, 62.9% of the 2-processor group responded that it was very important (P = .001). The most common reason for utilizing the second processor was a damaged primary processor. Patients who received 2 processors had a significantly lower number of postoperative audiology clinic visits for device troubleshooting (P < .001).

CONCLUSION

Patients who have 2 CI external processors identify this as being very important to them and experience significantly less time without access to sound due to lack of a functioning processor. As institutional contracts often dictate whether a patient will receive 1 or 2 sound processors with their CI hardware, it is important to understand patient preferences and utilization patterns in order to guide patient-centric policies.

Cochlear Implant Qualification in Noise Versus Quiet: Do Patients Demonstrate Similar Postoperative Benefits?

OBJECTIVE

To assess patient factors, audiometric performance, and patient-reported outcomes in cochlear implant (CI) patients who would not have qualified with in-quiet testing alone.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

METHODS

Adult CI recipients implanted between 2012 and 2022 were identified. Patients with preoperative AzBio Quiet > 60% in the implanted ear, requiring multitalker babble to qualify, comprised the in-noise qualifying (NQ) group. NQ postoperative performance was compared with the in-quiet qualifying (QQ) group using CNC, AzBio Quiet, and AzBio +5 dB signal-to-noise ratio. Speech, Spatial and Qualities of Hearing Scale (SSQ), Cochlear Implant Quality of Life scale (CIQOL-10), and daily device usage were also compared between the groups.

RESULTS

The QQ group (n = 771) and NQ group (n = 67) were similar in age and hearing loss duration. NQ had higher average preoperative and postoperative speech recognition scores. A larger proportion of QQ saw significant improvement in CNC and AzBio Quiet scores in the CI-only listening condition (eg, CI-only AzBio Quiet: 88% QQ vs 51% NQ, P < .001). Improvement in CI-only AzBio +5 dB and in all open set testing in the best-aided binaural listening condition was similar between groups (eg, Binaural AzBio Quiet 73% QQ vs 59% NQ, P = .345). Postoperative SSQ ratings, CIQOL scores, and device usage were also equivalent between both groups.

CONCLUSION

Patients who require in-noise testing to meet CI candidacy demonstrate similar improvements in best-aided speech perception and patient-reported outcomes as in-QQ, supporting the use of in-noise testing to determine CI qualification for borderline CI candidates.

Effects of Economic Status on Changes in Social Networks and Mental Health after Using Hearing Aids

OBJECTIVES

Hearing impairment affects social networks and mental health. Hearing aids (HA) can improve these deficits. However, their effects might be affected by various factors such as economic status (ES). This study aimed to identify how ES could moderate the effects of HA on social networks, depressive mood, and cognition.

METHODS

A prospective cohort for new HA users was established and classified into two groups based on their ES: a low ES group (LES group) and a medium to high ES group (MHES group). Audiological examination, Lubben social network scale-18 (LSNS-18), Short form of Geriatric Depression Score, Mini-Mental State Examination in the Korean version of the CERAD Assessment Packet, and surveys for satisfaction with HA were conducted before and at six months after wearing HA.

RESULTS

Post-HA application LSNS-18 scores were not improved in the LES group whereas they revealed significant improvement in the MHES group (p = 0.003). The LES group showed lower LSNS-18 score (p = 0.020) and its change (p = 0.042) than the MHES group. Additionally, patients with depressive moods in the MHES group showed better improvements than those in the LES group (p = 0.048). The effects of wearing HA on cognition and satisfaction with HA were not significantly different between the two groups.

CONCLUSIONS

HA did not improve social relationships and depressive moods in the LES group. Comprehensive and multidirectional support as well as hearing rehabilitation may be important for patients with LES.

LEVEL OF EVIDENCE

3 (Nonrandomized controlled cohort/follow-up study) Laryngoscope, 134:2387-2394, 2024.

Bilateral Cochlear Implants and Bimodal Hearing: A Comparison of Quality of Life

BACKGROUND

 Despite significant advances in the field of cochlear implants (CIs), there is no widely accepted criterion for when to counsel on bilateral CIs in adults. This is partly due to conflicting findings on the advantages of bilateral CIs versus bimodal hearing (i.e., CI with a contralateral hearing aid). Because of this, clinicians rely on a poorly defined combination of clinical measures and patient discussion to evaluate a patient's listening needs and preferences. Patients' needs and preferences are often used to guide recommendations on whether bilateral CIs or bimodal hearing is best for that individual, suggesting that an in-depth comparison of each group's self-reported outcomes is warranted.

PURPOSE

 Given the limited number of studies directly comparing quality of life (QoL) in bimodal and bilateral patients, the current study conducted a preliminary comparison of self-reported outcomes to better understand patient-reported benefits of each listening configuration.

RESEARCH DESIGN

 This was a between-subjects comparison.

STUDY SAMPLE

 Fifteen bimodal and nine bilateral adult CI users made the study sample.

DATA COLLECTION AND ANALYSIS

 Participants completed the Cochlear Implant Quality of Life (CIQOL) Profile 35. For group comparison purposes, monosyllabic word recognition and nonverbal intelligence were measured. Independent samples t-tests with Holm-Bonferroni corrections were used to compare bimodal and bilateral patients across domains of the CIQOL.

RESULTS

 Bilateral CI users self-reported better environmental, emotional, social, and global QoL when compared to bimodal users. The groups did not differ on age, nonverbal intelligence, speech recognition abilities, and duration of hearing loss; however, bimodal users had less experience listening with their CI than the bilateral CI users.

CONCLUSION

 Bilateral CI users showed widespread advantages in QoL when compared to bimodal users. Bilateral CI users self-reported significantly better environmental QoL which conflicts with previous in-lab and self-report results suggesting a bimodal advantage. Additionally, due to a lack of current literature, it is unclear why a bilateral advantage is observed for emotional and social QoL. Results of the current study not only provide additional support on the benefits of bilateral implantation but also stress the need to further explore the self-reported benefits of each listening configuration.

First clinical implementation of insertion force measurement in cochlear implantation surgery

Purpose

The significance of atraumatic electrode array (EA) insertion in cochlear implant (CI) surgery is widely acknowledged, with consensus that forces due to EA insertion are directly correlated with insertion trauma. Unfortunately, the manual perception of these forces through haptic feedback is inherently limited, and techniques for in vivo force measurements to monitor the insertion are not yet available. Addressing this gap, we developed of a force-sensitive insertion tool capable of capturing real-time insertion forces during standard CI surgery.

Methods

This paper describes the tool and its pioneering application in a clinical setting and reports initial findings from an ongoing clinical study. Data and experiences from five patients have been evaluated so far, including force profiles of four patients.

Results

The initial intraoperative experiences are promising, with successful integration into the conventional workflow. Feasibility of in vivo insertion force measurement and practicability of the tool's intraoperative use could be demonstrated. The recorded in vivo insertion forces show the expected rise with increasing insertion depth. Forces at the end of insertion range from 17.2 mN to 43.6 mN, while maximal peak forces were observed in the range from 44.8 mN to 102.4 mN.

Conclusion

We hypothesize that this novel method holds the potential to assist surgeons in monitoring the insertion forces and, thus, minimizing insertion trauma and ensuring better preservation of residual hearing. Future data recording with this tool can form the basis of ongoing research into the causes of insertion trauma, paving the way for new and improved prevention strategies.

Cochlear Implant Referral Criteria for the Spanish-Speaking Adult Population

OBJECTIVE

To evaluate the effectiveness of the "60/60 Guideline" in a diverse patient population.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

Data were collected for adult patients (18 years and older) who underwent a cochlear implant evaluation (CIE) between January 2016 and March 2021.

MAIN OUTCOME MEASURES

Development of the "60/60 Guideline" has provided better clarity on when to refer English-speaking patients for a CIE. Our study evaluated the effectiveness of this referral tool in the Spanish-speaking population.

RESULTS

In our group of patients who underwent a traditional CIE (n = 402), 209 met unaided and aided traditional cochlear implant (CI) candidacy criteria. Of the 193 individuals who did not meet both components of traditional candidacy criteria, a majority met the aided component (86%) but only 4.6% met the unaided component. When applying the 60/60 Guideline to patients who met traditional criteria, there is a sensitivity rating of 84.7% and a specificity index of 50.3%. For English and Spanish speakers who met traditional criteria but did not meet the 60/60 Guideline, a majority (83.3% English, 87.5% Spanish) had a better ear word recognition score (WRS) greater than 60%, suggesting the unaided WRS is the more restrictive component of the "60/60 Guideline."

CONCLUSION

Application of the "60/60 Guideline" is an effective method to identify potential CI candidates in the English-speaking population; however, it was less effective in the Spanish-speaking population. Spanish-speaking adults should be referred for a CIE when better ear pure tone average is greater than 60 dB hearing loss, regardless of their unaided WRS. This study highlights the need for inclusion of nonlinguistic test measures in the CI referral criteria and test battery to reduce CI access barriers for patients who speak a language other than English.

Cochlear Implantation in the Elderly: Speech Performance, Associated Factor, Complication, and Surgical Safety

BACKGROUND AND OBJECTIVES

The guidelines for cochlear implantation (CIs) are expanding, and the number of CI procedures performed on the elderly is increasing. The purpose of this study was to analyze the results and safety of cochlear implantation in the elderly, as well as to evaluate the predictive factors on CI outcomes.

SUBJECTS AND METHODS

The study included 56 patients aged ≥40 years, who received CIs between 2009 and 2020. They were divided into two groups: 27 younger adults (40-64 years) and 29 elderly (>64 years). The study compared their pre- and postoperative speech perception and category of auditory performance (CAP) scores, surgical complications, and hospitalization periods. It also evaluated associated factors in the elderly group by examining categorical and continuous variables and postoperative CAP score.

RESULTS

There was a significant improvement in speech recognition tests (both word and sentence) and CAP scores in both groups compared to the pre-implantation scores (p<0.001). Postoperative results were slightly lower in the elderly group than in younger adults for sentence recognition and CAP scores, except for word recognition. No significant associated factors were found on postoperative CAP scores, except for etiology. Postoperative CAP significantly improved in the sudden hearing loss group compared to the groups with other etiologies (p=0.045). The elderly group had more comorbidities than that in the younger adult group (p=0.026), but there were no significant differences in postoperative complications and hospitalization periods.

CONCLUSIONS

While speech recognition and CAP scores were relatively lower in the elderly group compared to the younger adults, the elderly group showed significant improvements in audiological results after CI. Moreover, CI was safe and well tolerated in elderly patients.

Socioeconomic Status Among Cochlear Implant Candidates and Association With Surgical Pursuance

Importance

Despite the sizeable global burden of hearing loss, cochlear implants have poor penetrance among eligible hearing-impaired individuals. Identifying populations who may benefit from a cochlear implant but among whom penetrance is poor is an important aim in reducing the health-related and economic effects of hearing loss on both individuals and society.

Objectives

To explore the association of socioeconomic status (SES) with cochlear implant candidacy and the decision to undergo cochlear implantation.

Design, Setting, and Participants

This retrospective cohort study was performed in a tertiary academic center. All adult patients evaluated for cochlear implant candidacy from January 1, 1999, through December 31, 2022, were included in the analysis.

Exposures

Household income quintile and rural or urban residence were used as proxies for SES based on zip code linkage to US Census and US Department of Agriculture data.

Main Outcomes and Measures

Odds of cochlear implant candidacy and surgery.

Results

A total of 754 individuals underwent candidacy evaluations and were included in the analysis (386 [51.2%] women; mean [SD] age, 64.0 [15.7] years). Of these, 693 (91.9%) were cochlear implant candidates, and 623 candidates (89.9%) underwent cochlear implantation. Multivariable analyses demonstrated that individuals in the highest income quintile had lower odds of cochlear implant candidacy compared with those in the lowest income quintile (odds ratio [OR], 0.26 [95% CI, 0.08-0.91]), and candidates in the highest income quintile had greater odds of undergoing cochlear implant surgery compared with those in the lowest quintile (OR, 2.59 [95% CI, 1.14-5.86]). Living in a small town or a micropolitan or rural area was associated with lower odds of undergoing cochlear implant surgery compared with living in a metropolitan core (OR, 0.18 [95% CI, 0.04-0.83]) after controlling for distance to the primary implant center.

Conclusions and Relevance

The findings of this cohort study suggest that individuals with higher SES are less likely to qualify for a cochlear implant; however, those who qualify are more likely to undergo surgery compared with those with lower SES. These findings highlight a hearing health care disparity that should be addressed through further studies to guide population-based initiatives.

Machine Learning Approach for Screening Cochlear Implant Candidates: Comparing With the 60/60 Guideline

OBJECTIVE

To develop a machine learning-based referral guideline for patients undergoing cochlear implant candidacy evaluation (CICE) and to compare with the widely used 60/60 guideline.

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary referral center.

PATIENTS

772 adults undergoing CICE from 2015 to 2020.

INTERVENTIONS

Variables included demographics, unaided thresholds, and word recognition score. A random forest classification model was trained on patients undergoing CICE, and bootstrap cross-validation was used to assess the modeling approach's performance.

MAIN OUTCOME MEASURES

The machine learning-based referral tool was evaluated against the 60/60 guideline based on ability to identify CI candidates under traditional and expanded criteria.

RESULTS

Of 587 patients with complete data, 563 (96%) met candidacy at our center, and the 60/60 guideline identified 512 (87%) patients. In the random forest model, word recognition score; thresholds at 3000, 2000, and 125; and age at CICE had the largest impact on candidacy (mean decrease in Gini coefficient, 2.83, 1.60, 1.20, 1.17, and 1.16, respectively). The 60/60 guideline had a sensitivity of 0.91, a specificity of 0.42, and an accuracy of 0.89 (95% confidence interval, 0.86-0.91). The random forest model obtained higher sensitivity (0.96), specificity (1.00), and accuracy (0.96; 95% confidence interval, 0.95-0.98). Across 1,000 bootstrapped iterations, the model yielded a median sensitivity of 0.92 (interquartile range [IQR], 0.85-0.98), specificity of 1.00 (IQR, 0.88-1.00), accuracy of 0.93 (IQR, 0.85-0.97), and area under the curve of 0.96 (IQR, 0.93-0.98).

CONCLUSIONS

A novel machine learning-based screening model is highly sensitive, specific, and accurate in predicting CI candidacy. Bootstrapping confirmed that this approach is potentially generalizable with consistent results.

Robotized Cochlear Implantation under Fluoroscopy: A Preliminary Series

It is known that visual feedback by fluoroscopy can detect electrode array (EA) misrouting within the cochlea while robotized EA-insertion (rob-EAI) permits atraumatic cochlear implantation. We report here our unique experience of both fluoroscopy feedback and rob-EAI in cochlear implant surgery. We retrospectively analyzed a cohort of consecutive patients implanted from November 2021−October 2022 using rob-EAI, with the RobOtol®, to determine the quality of EA-insertion and the additional time required. Twenty-three patients (10 females, 61+/−19 yo) were tentatively implanted using robot assistance, with a rob-EAI speed < 1 mm/s. Only three cases required a successful revised insertion by hand. Under fluoroscopy (n = 11), it was possible to achieve a remote rob-EAI (n = 8), as the surgeon was outside the operative room, behind an anti-radiation screen. No scala translocation occurred. The additional operative time due to robot use was 18+/−7 min with about 4 min more for remote rob-EAI. Basal cochlear turn fibrosis precluded rob-EAI. In conclusion, Rob-EAI can be performed in almost all cases with a low risk of scala translocation, except in the case of partial cochlear obstruction such as fibrosis. Fluoroscopy also permits remote rob-EAI.

Acoustic Change Complex Recorded in Hybrid Cochlear Implant Users

INTRODUCTION

Expanding cochlear implant (CI) candidacy criteria and advances in electrode arrays and soft surgical techniques have increased the number of CI recipients who have residual low-frequency hearing. Objective measures such as obligatory cortical auditory-evoked potentials (CAEPs) may help clinicians make more tailored recommendations to recipients regarding optimal listening mode. As a step toward this goal, this study investigated how CAEPs measured from hybrid CI users differ in two listening modes: acoustic alone (A-alone) versus acoustic plus electric (A + E).

METHODS

Eight successful hybrid CI users participated in this study. Two CAEPs, the P1-N1-P2 and the acoustic change complex (ACC), were measured simultaneously in response to the onset and change of a series of different and spectrally complex acoustic signals, in each of the two listening modes (A-alone and A + E). We examined the effects of listening mode and stimulus type on the onset and ACC N1-P2 amplitudes and peak latencies.

RESULTS

ACC amplitudes in hybrid CI users significantly differed as a function of listening mode and stimulus type. ACC responses in A + E were larger than those in the A-alone mode. This was most evident for stimuli involving a change from low to high frequency.

CONCLUSIONS

Results of this study showed that the ACC varies as a function of listening mode and stimulus type. This finding suggests that the ACC can be used as a physiologic, objective measure of the benefit of hybrid CIs, potentially supporting clinicians in making clinical recommendations on individualized listening mode, or to document subjective preference for a given listening mode. Further research into this potential clinical application in a range of hybrid recipients and/or long electrode users who have residual low-frequency hearing is warranted.

An optically-guided cochlear implant sheath for real-time monitoring of electrode insertion into the human cochlea

In cochlear implant surgery, insertion of perimodiolar electrode arrays into the scala tympani can be complicated by trauma or even accidental translocation of the electrode array within the cochlea. In patients with partial hearing loss, cochlear trauma can not only negatively affect implant performance, but also reduce residual hearing function. These events have been related to suboptimal positioning of the cochlear implant electrode array with respect to critical cochlear walls of the scala tympani (modiolar wall, osseous spiral lamina and basilar membrane). Currently, the position of the electrode array in relation to these walls cannot be assessed during the insertion and the surgeon depends on tactile feedback, which is unreliable and often comes too late. This study presents an image-guided cochlear implant device with an integrated, fiber-optic imaging probe that provides real-time feedback using optical coherence tomography during insertion into the human cochlea. This novel device enables the surgeon to accurately detect and identify the cochlear walls ahead and to adjust the insertion trajectory, avoiding collision and trauma. The functionality of this prototype has been demonstrated in a series of insertion experiments, conducted by experienced cochlear implant surgeons on fresh-frozen human cadaveric cochleae.

A Five-Year Update on the Profile of Adults Undergoing Cochlear Implant Evaluation and Surgery-Are We Doing Better?

OBJECTIVE

To characterize the influence of expanding indications on the profile of adults undergoing cochlear implantation (CI) at a high-volume CI center.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

774 adults undergoing CI evaluation from August 2015 to August 2020.

MAIN OUTCOME MEASURES

Demographics; audiometry; speech recognition; speech, spatial, and qualities of hearing scale (SSQ-12).

RESULTS

Of 745 (96.3%) patients qualifying for implantation, 642 (86.6%) pursued surgery. Median age at evaluation was 69 years; 56.3% were men; 88.2% were Caucasian. Median distance to our center was 95 miles. The majority (51.8%) had public insurance (Medicare, Medicaid), followed by private (47.8%) and military (0.4%). Mean PTA, CNC, and AzBio in quiet and noise for the ear to be implanted were 85.2 dB HL, 15.0%, and 19.2% and 3.5%, respectively. Hybrid/EAS criteria were met by 138 (18.5%) CI candidates, and 436 (77.0%) unilateral CI recipients had aidable contralateral hearing for bimodal hearing configurations. Younger age (odds ratio [OR], 0.96; 95% confidence interval, 0.93-0.99) and non-Caucasian race (OR, 6.95; 95% confidence interval, 3.22-14.98) predicted candidacy. Likelihood of surgery increased for Caucasian (OR, 8.08; 95% confidence interval, 4.85-13.47) and married (OR, 2.28; 95% confidence interval, 1.50-3.47) patients and decreased for those with public insurance (OR, 0.45; 95% confidence interval, 0.29-0.69). A lower SSQ-12 score predicted both candidacy and surgery.

CONCLUSION

Despite expansions in criteria, speech understanding remained extremely low at CI evaluation. Younger age and non-Caucasian race predicted candidacy, and Caucasian, married patients with private insurance and lower SSQ scores were more likely to pursue surgery.

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.

Conversations in Cochlear Implantation: The Inner Ear Therapy of Today

As biomolecular approaches for hearing restoration in profound sensorineural hearing loss evolve, they will be applied in conjunction with or instead of cochlear implants. An understanding of the current state-of-the-art of this technology, including its advantages, disadvantages, and its potential for delivering and interacting with biomolecular hearing restoration approaches, is helpful for designing modern hearing-restoration strategies. Cochlear implants (CI) have evolved over the last four decades to restore hearing more effectively, in more people, with diverse indications. This evolution has been driven by advances in technology, surgery, and healthcare delivery. Here, we offer a practical treatise on the state of cochlear implantation directed towards developing the next generation of inner ear therapeutics. We aim to capture and distill conversations ongoing in CI research, development, and clinical management. In this review, we discuss successes and physiological constraints of hearing with an implant, common surgical approaches and electrode arrays, new indications and outcome measures for implantation, and barriers to CI utilization. Additionally, we compare cochlear implantation with biomolecular and pharmacological approaches, consider strategies to combine these approaches, and identify unmet medical needs with cochlear implants. The strengths and weaknesses of modern implantation highlighted here can mark opportunities for continued progress or improvement in the design and delivery of the next generation of inner ear therapeutics.