Association of Patient-Related Factors With Adult Cochlear Implant Speech Recognition Outcomes: A Meta-analysis

Preoperative MRI, audiovisual speech perception, and mood are associated with cochlear implant outcomes in adults with postlingual deafness

Acquired severe to profound hearing loss is an increasingly challenging problem of our aging population. Cochlear implantation (CI) is the gold standard treatment for this advanced form of sensory deprivation. Despite the overall satisfactory results of CI, a substantial number of patients show unsatisfactory outcomes. This study aims to improve current predictive models of CI outcome by integrating preoperative MRI with behavioral data. We acquired a 3D T1 MRI to measure cortical thickness (CT) and volume using surface-based analysis and parcellation from the Brainnetome atlas. CI success at 6 months post-implant, as measured by audiovisual speech perception, was correlated with preoperative speech and audiovisual perception with hearing aids, and residual hearing, especially at the side of the non-implanted ear. In addition, CI outcome correlated positively with CT of the left superior temporal gyrus and sulcus, left inferior frontal region, and bilateral superior frontal regions. The volume of the left middle frontal gyrus and regions of the parietal lobe, especially at the left side, also correlated with CI outcome. Linear regression models revealed that CI outcome was best predicted by the combination of preoperative measures of audiovisual speech perception, residual hearing, depression and CT. Our results highlight the importance of preserved brain areas implicated in hearing, language, audiovisual integration, and cognitive functions for CI success. Furthermore, brain MRI in conjunction with other predictors can help to identify patients who may need more time to adjust to the CI, allowing a more tailored rehabilitation, and potentially greater efficacy.

ECAP correlation with speech recognition performance - new predictory function in rehabilitation of cochlear implant recipients?

<b>Introduction:</b> Despite well-established qualification criteria and pre-operation tests, there is still uncertainty about post-implantation performance in CI patients. One of the most interesting factors that affect the outcome is the survivability and function of cochlear nerve endings. ECAP (Evoked Compound Action Potential) is one of the tools that might be useful in the prediction of rehabilitation outcomes. Speech audiometry is one of the most commonly used and established performance tests. The study hypothesis is that there might be a correlation between ECAP values and speech audiometry results obtained over time.<b>Aim:</b> The aim was to check if changes within postop ECAP values correspond tochanges in speech intelligibility.<b>Materials and methods:</b> The study was designed as a retrospective observational one. Data was evaluated on a selected group of patients, with no blinding or control group. The study group consisted of 25 adult cochlear implant recipients, all with Cochlear devices, implanted at the Department of Otolaryngology of the Medical University of Bialystok, Poland, between 2016 and 2020. Data included ECAP measurements and speech audiometry results obtained during the first year of rehabilitation. The statistical analysis of the significance of data change over time and its correlation was performed.<b>Results:</b> Change of data over time was significant (P<0.05) for almost all data groups but it did not translates to the correlation of speech and ECAP.<b>Conclusions:</b> There is no statistically confirmed evidence suggesting that obtaining speech intelligibility is connected with change in ECAP values, which requires further research.

Machine Learning Feasibility in Cochlear Implant Speech Perception Outcomes-Moving Beyond Single Biomarkers for Cochlear Implant Performance Prediction

OBJECTIVES

Machine learning (ML) is an emerging discipline centered around complex pattern matching and large data-based prediction modeling and can improve precision medicine healthcare. Cochlear implants (CI) are highly effective, however, outcomes vary widely, and accurately predicting speech perception performance outcomes between patients remains a challenge. This study aims to evaluate the ability of ML to predict speech perception performance among CI recipients at 6-month post-implantation using only preoperative variables on one of the largest CI datasets to date, with an emphasis placed on identification of poor performers.

DESIGN

All patients enrolled in the national CI outcome tracking database, HERMES, and the institutional CI registry. Data were split 90/10 training/testing with hyperparameter tuning designed to optimize AUPRC performed during 10-fold cross-validation within 100 iterations. Multiple models were developed to predict final and delta (Δ) in consonant-nucleus-consonant (CNC) words and AzBio sentences at 6-month post-implantation. Two metrics, (1) final performance scores and (2) equally distributed 20th percentile performance ranking were used as primary outcomes. All models were compared with currently used "gold standard," defined as linear or logistic regression models leveraging Lazard features (LF). Final metrics for comparison included mean absolute error (MAE), calibration curves, heat accuracy maps, area under the receiver operating curve (AUROC), and F1 score.

RESULTS

A total of 1877 patients were assessed through an ML pipeline. (1) XGBoost (XGB) predicted CNC with MAE of 17.4% (95% confidence interval [CI]: 17.34 to 17.53%) and AzBio with MAE of 20.39% (95% CI: 20.28 to 20.50%) and consistently outperformed linear regression with LF (CNC MAE 18.36% [95% CI: 18.25 to 18.47]; AzBio 21.62 [95% CI: 21.49 to 21.74]). Although statistically significant, the 1 to 2% boost of performance is clinically insignificant. (2) Predicting quintiles/20th percentile categories for CI performance, XGB outperformed logistic regression (Log-LF) across all metrics. XGB demonstrated superior calibration compared with Log-LF and provided a larger proportion of predicted probabilities predictions at the extremes (e.g., 0.1 or 0.9). XGB outperformed Log-LF predicting ≤40th percentile for CNC (AUROC: 0.708 versus 0.594; precision: 0.708 versus 0.596; F1 score: 0.708 versus 0.592) and AzBio (AUROC: 0.709 versus 0.572; precision: 0.710 versus 0.572; F1 score: 0.709 versus 0.572). This was consistent for ΔCNC and ΔAzBio. Last, accuracy heat maps demonstrated superior performance of XGB in stratifying sub-phenotypes/categories of CI performance compared with Log-LF.

CONCLUSIONS

This study demonstrates how ML models can offer superior performance in CI speech perception outcomes prediction modeling compared with current gold standard (Lazard-linear or logistic regression). ML offers novel insights capable of capturing nonlinear complex relationships and can identify novel sub-phenotypes at the extremes of CI performance using preoperative clinical variables alone. This is the first study to our knowledge to offer any type of meaningful preoperative stratification for CI speech perception outcomes and may have significant implications that need to be carefully explored when it comes to patient counseling, auditory rehabilitation, and future CI clinical trials. While prospective validation is a necessary next step and performance is still limited based on current traditional CI variables, these results highlight the potential of artificial intelligence (AI) in CI care, the critical need to integrate novel variables that better account for CI performance, and the need for improved data collaboration and standardized registries moving forward.

Auditory working memory in noise in cochlear implant users: Insights from behavioural and neuronal measures

OBJECTIVE

We investigated auditory working-memory using behavioural measures and electroencephalography (EEG) in adult Cochlear Implant (CI) users with varying degrees of CI performance.

METHODS

24 adult CI listeners (age: M = 61.38, SD = 12.45) performed the Sternberg auditory-digit-in-working-memory task during which EEG, accuracy, and promptness were captured. Participants were presented with 2, 4, or 6 digits at Signal-to-Noise Ratios (SNR) of 0, +5 and +10dB. They had to identify a probe stimulus as present in the preceding sequence. ANOVA models were used to compare conditions.

RESULTS

ANOVA revealed that increasing memory load (ML) led to decreased task performance and CI performance interacted with ML and SNR. Centro-parietal alpha power increased during memory encoding but did not differ between conditions. Frontal alpha power was positively correlated with accuracy in conditions most affected by SNR (r = 0.57, r = 0.52) and theta power in conditions most affected by ML (r = 0.55, r = 0.57).

CONCLUSIONS

While parietal alpha power is modulated by the task, it is frontal alpha that relates quantitatively to sensory aspects of processing (noise) and frontal theta to memory load in this group of CI listeners.

SIGNIFICANCE

These results suggest that alpha and theta show distinct relationships to behaviour, providing additional insight into neurocognitive (auditory working-memory) processes in CI users.

Machine-Learning Predictions of Cochlear Implant Functional Outcomes: A Systematic Review

OBJECTIVES

Cochlear implant (CI) user functional outcomes are challenging to predict because of the variability in individual anatomy, neural health, CI device characteristics, and linguistic and listening experience. Machine learning (ML) techniques are uniquely poised for this predictive challenge because they can analyze nonlinear interactions using large amounts of multidimensional data. The objective of this article is to systematically review the literature regarding ML models that predict functional CI outcomes, defined as sound perception and production. We analyze the potential strengths and weaknesses of various ML models, identify important features for favorable outcomes, and suggest potential future directions of ML applications for CI-related clinical and research purposes.

DESIGN

We conducted a systematic literature search with Web of Science, Scopus, MEDLINE, EMBASE, CENTRAL, and CINAHL from the date of inception through September 2024. We included studies with ML models predicting a CI functional outcome, defined as those pertaining to sound perception and production, and excluded simulation studies and those involving patients without CIs. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we extracted participant population, CI characteristics, ML model, and performance data. Sixteen studies examining 5058 pediatric and adult CI users (range: 4 to 2489) were included from an initial 1442 publications.

RESULTS

Studies predicted heterogeneous outcome measures pertaining to sound production (5 studies), sound perception (12 studies), and language (2 studies). ML models use a variety of prediction features, including demographic, audiological, imaging, and subjective measures. Some studies highlighted predictors beyond traditional CI audiometric outcomes, such as anatomical and imaging characteristics (e.g., vestibulocochlear nerve area, brain regions unaffected by auditory deprivation), health system factors (e.g., wait time to referral), and patient-reported measures (e.g., dizziness and tinnitus questionnaires). Used ML models were tree-based, kernel-based, instance-based, probabilistic, or neural networks, with validation and test methods most commonly being k-fold cross-validation and train-test split. Various statistical measures were used to evaluate model performance, however, for studies reporting accuracy, the best-performing models for each study ranged from 71.0% to 98.83%.

CONCLUSIONS

ML models demonstrate high predictive performance and illuminate factors that contribute to CI user functional outcomes. While many models showed favorable evaluation statistics, the majority were not adequately reported with regard to dataset characteristics, model creation, and validation. Furthermore, the extent of overfitting in these models is unclear and will likely result in poor generalization to new data. This suggests the need for more robust validation procedures and standardization in reporting, with the ultimate hope that the iterative improvement of these models will allow for their adoption as a future clinical tool.

Accuracy and variability in clinical predictions of speech recognition outcomes for cochlear implant users

OBJECTIVES

An improvement in speech perception is a major well-documented benefit of cochlear implantation (CI), which is commonly discussed with CI candidates to set expectations. However, a large variability exists in speech perception outcomes. We evaluated the accuracy of clinical predictions of post-CI speech perception scores.

DESIGN

In an online survey, clinicians involved in CI care were asked to predict 6-month performance on AzBio sentences and CNC words for 15 anonymised CI patients based on demographic, medical, and audiological data, and preoperative speech recognition scores.

STUDY SAMPLE

Sixty-five participants (72% audiologists, 14% neurotologists, 14% speech-language pathologists, and CI researchers) provided predictions for two or more cases, and 43 provided predictions for all 15 CI cases.

RESULTS

Clinical predictions had low accuracy and high variability (i.e. median interclass correlation coefficients [ICC] 0.11-0.13). No relationship was observed between clinicians' confidence and prediction accuracy.

CONCLUSIONS

The present findings are consistent with previous research and indicate a concerning discrepancy between clinical predictions and actual speech perception outcomes for adult post-lingual CI users. Future research may explore incorporating predictions based on statistical models into speech outcome prognostication to reduce variance and improve counselling and expectations setting for individual CI candidates.

Utilization of the Spanish Bisyllable Word Recognition Test to Assess Cochlear Implant Performance Trajectory

Objectives: The aims of this study were to compare pre- and post-operative word recognition scores (WRSs) for the adult Spanish-speaking population and to describe their cochlear implant (CI) performance trajectory. Methods: A retrospective chart review (n = 115) was completed for Spanish-speaking post-lingually deafened adults who underwent a traditional CI evaluation and subsequent surgery between 2018 and 2023. Pre- and post-CI (3, 6, 12-month) Spanish Bisyllable WRSs and CI datalogging (hours per day) were collected for 66 subjects who met inclusion. Patients were, on average, 61.4 years of age (SD = 14.9) at the time of their first CI, and all were Hispanic and White (100%). Results: The outcomes of the 66 subjects who met the inclusion criteria were analyzed. Spanish Bisyllable WRSs improved at all post-CI test intervals, though the mean change between intervals showed a decreasing trend over time, with a plateau in WRSs occurring by 6 months post-CI. Time was a significant predictor of increased post-CI WRSs at 6 months (p = 0.004) and 12 months (p < 0.001). Sex, the implanted ear, electrode type, CI manufacturer, and datalogging hours did not significantly predict Bisyllable WRSs. Conclusions: This study used the largest cohort dataset to date to describe pre-and post-CI WRSs for Spanish-speaking adults. The post-CI performance trajectory is similar in Spanish-speaking CI recipients compared to English-speaking cohorts. This study is fundamental in providing evidence-based outcomes for Spanish-speaking CI recipients and will assist clinicians with pre-CI counseling based on realistic expectations.

Determinants of Success in Revision Cochlear Implant Surgeries: A Comprehensive Evaluation of Patient, Surgical, and Radiological Factors

Background/Objectives: This study aims to evaluate factors influencing revision cochlear implant surgeries, including patient demographics, surgical techniques, and radiological findings. The main aim was to identify factors influencing surgical success to inform clinical treatment and enhance patient outcomes. Methods: This cross-sectional study included adult patients over the age of 18 who underwent revision cochlear implant surgery due to implant-related complications. Data were collected from systematic chart reviews of electronic medical records, including demographics, surgical techniques, radiological output from standard high-resolution CT and MRI, and intraoperative data. The primary outcome was surgical success, defined by improved auditory function, stable device positioning, and absence of postoperative complications. Statistical analyses, including multivariate logistic regression, were conducted to identify independent predictors of surgical success. Results: A total of 188 patients were included, with a mean age of 45.67 years. Younger age, shorter duration of implant use, modified surgical techniques, and absence of co-morbidities are key factors contributing to surgical success. Modified surgical techniques were associated with better outcomes (39.29% vs. 68.75%, OR: 2.78, 95% CI: 1.25-6.14, p = 0.012). Radiological patterns significantly affected outcomes, with normal findings associated with higher success rates. In contrast, abnormalities such as electrode migration (OR: 2.14, 95% CI: 1.12-4.09, p = 0.021) and ossification (r = -0.51, β = -0.44, adjusted R2 = 0.25, p < 0.01) were correlated with poorer results. Smoking status, when comparing smokers to non-smokers, was associated with unfavorable outcomes (20.00% vs. 45.83%, OR: 2.01, 95% CI: 1.01-4.01, p = 0.048), and a history of previous surgeries (21.43% vs. 37.50%, OR: 1.95, 95% CI: 1.03-3.71, p = 0.033) was significantly associated with unfavorable outcomes. Conclusions: Statistically, significantly better outcomes are positively correlated with the duration of the first cochlear implant experience and negatively with prior otologic pathology and nonauditory environmental influences on surgical success. Younger age, modified surgical techniques, and normal radiological findings were related to better outcomes; complications such as electrode migration and ectopic ossification were strong predictive factors for surgical failure. These findings underscore the need for tailored surgical approaches and early intervention to enhance outcomes in revision cochlear implant surgeries.

Individualized post-operative prediction of cochlear implantation outcomes in children with prelingual deafness using functional near-infrared spectroscopy

Objective

The goal of this study was to develop an objective measure and predictor of cochlear implantation (CI) outcomes using functional near-infrared spectroscopy (fNIRS) for young children with prelingual deafness.

Methods

Sound-evoked hemodynamic responses were recorded from auditory and language-related cortical regions of 47 child CI recipients (35.47 ± 17.24 months of age) using fNIRS shortly after CI activation (0.26 ± 0.30 months). There were four sound conditions (natural speech, instrumental music, multi-speaker babble noise, and speech-in-noise). Post-CI auditory and verbal communication performance was evaluated using clinical questionnaires with caretakers. Both classification and individualized regression models were constructed to predict post-CI behavioral improvement from fNIRS data using support vector machine (SVM) learning algorithms.

Results

Auditory cortical responses shortly after CI hearing onset yielded highly accurate prediction of behavioral development in young CI children. For classification models, optimal prediction was achieved using cortical responses to two or more sound conditions, with the highest accuracy of 98.20% (precision = 98.17%, sensitivity = 98.96%, area under the curve of the receiver operating characteristic curve = 99.61%) obtained with the combination of speech, noise, and music stimuli. Similarly, for regression models, best prediction of individual development was achieved using three (highest r = 0.919) or four (r = 0.966) sound conditions. The predictability of cortical responses far outperformed (Cohen's d: 18.56) that of the collection of audiological and demographic parameters (classification accuracy: 0.62) under the same SVM algorithms and could not benefit from the inclusion of the latter.

Conclusion

Machine learning models using auditory cortical hemodynamic responses shortly after CI activation were able to predict individualized post-CI behavioral improvement in children with prelingual deafness.

Level of Evidence

Level 5.

Barriers to Cochlear Implant Uptake in Adults: A Scoping Review

INTRODUCTION

Cochlear implants (CIs) provide access to sound and help mitigate the negative effects of hearing loss. As a field, we are successfully implanting more adults with greater amounts of residual hearing than ever before. Despite this, utilization remains low, which is thought to arise from barriers that are both intrinsic and extrinsic. A considerable body of literature has been published in the last 5 years on barriers to adult CI uptake, and understanding these barriers is critical to improving access and utilization. This scoping review aims to summarize the existing literature and provide a guide to understanding barriers to adult CI uptake.

METHODS

Inclusion criteria were limited to peer-reviewed articles involving adults, written in English, and accessible with a university library subscription. A cutoff of 20 years was used to limit the search. Barriers uncovered in this review were categorized into an ecological framework.

RESULTS

The initial search revealed 2,315 items after duplicates were removed. One hundred thirty-one articles were reviewed under full-text, and 68 articles met the inclusion criteria.

DISCUSSION

Race, ethnicity, and reimbursement are policy and structural barriers. Public awareness and education are societal barriers. Referral and geographical challenges are forms of organizational barriers. Living context and professional support are interpersonal barriers. At the individual level, sound quality, uncertainty of outcome, surgery, loss of residual hearing, and irreversibility are all barriers to CI uptake. By organizing barriers into an ecological framework, targeted interventions can be used to overcome such barriers.

Investigating the effect of cochlear implant usage metrics on cortical auditory-evoked potential responses in adult recipients post-implantation

Introduction

This study examines the effect of cochlear implant (CI) device usage metrics on post-operative outcomes in unilateral CI recipients. The primary objective is to investigate the relationship between CI usage frequency (average daily CI use) and duration (total years of CI use) on electrically evoked cortical auditory-evoked potential (eCAEP) response peak latency (ms) and amplitude (μV).

Methods

Adult CI users (n = 41) who previously exhibited absent acoustically evoked CAEP responses participated in the study. The peak latency and amplitude of eCAEP P1-N1-P2 responses were recorded, when present for the apical, medial, and basal test electrode contacts. CI duration was defined as the number of years between the date of CI activation and date that eCAEP testing was performed. CI usage frequency was defined as the average number of hours per day of audio processor use, which was recorded using the CI programming software.

Results

Overall, 27 participants (65.85%) exhibited detectable eCAEP responses across one or more electrode contacts. Among these, 18 participants (43.9%) elicited eCAEP responses at all three electrode contacts, while 7 (17.07%) showed responses at two contacts, and 2 (4.88%) at one contact. For the remaining 14 participants (34.15%), eCAEP responses were either absent or undetectable. CI usage frequency (average daily CI use [hours/day]) was captured for 32 (78%) of the participants (median 10.35 h/day, range 0.2-16 h/day). Participants with present eCAEP responses for the basal electrode (n = 14) showed significantly higher CI usage frequency (11.8 h/day, p = 0.026) compared to those with non-detectable responses (6.25 h/day). An association was found between higher CI usage frequency and reduced N1 (p = 0.002), P2 (p = 0.0037) and P1-N1 inter-peak (p = 0.015) response latency (ms). While CI duration (total CI use [years]) did not differ significantly between groups based on the presence of eCAEP responses, an association was found between greater CI duration and increased eCAEP response amplitude (μV) for the P2 (p = 0.008) and N1-P2 peak-peak (p = 0.009) response components.

Discussion

Additionally, most (65.85%) participants who previously exhibited absent acoustic CAEP responses developed eCAEP responses after consistent CI use and increased CI experience. These findings may suggest a potential for cortical plasticity and adaptation with consistent CI use over time. Recognizing the impact of device usage metrics on neural responses post-implantation enhances our understanding of the importance of consistent daily CI use. Overall, these findings contribute to addressing the variability among CI users, improving post-operative outcomes and advancing the standard of personalized care in auditory rehabilitation.

Validation of direct recording of electrically evoked cortical auditory evoked potentials through a cochlear implant system

Cochlear implants (CI) are one of the most successful treatments available to enable individuals with severe to profound hearing loss to regain access to the world of sound. This is accomplished through the electrical stimulation of the auditory nerve using electrodes implanted inside the cochlea. The use of subjective user feedback makes the process of fitting these devices much more challenging in cases where users are not able to actively or accurately report their experience (e.g. pediatrics), making an objective measurement that reflects the accuracy or effectiveness of a program quite attractive. We recorded one objective measure, the electrically-stimulated cortical auditory evoked potential (eCAEP), non-invasively using the CI in response to a simulated speech sound in seven adult participants and compared it to their eCAEP recorded using a scalp EEG set-up. The eCAEPs recorded with CI electrodes were comparable to scalp recorded eCAEPs (grand mean cross-correlation of r = 0.83, individual mean cross-correlations ranged from 0.13 to 0.70). Evoked potential peaks P1, N1 and P2 showed no significant latency difference based on if the eCAEP was recorded on the scalp or using the CI. The eCAEP waveforms recorded via the CI appear to converge in a distinct P1-N1-P2 waveform by as early as 130 sweeps. In conclusion, in this study we show the feasibility of recording the eCAEP directly through the CI system, which could potentially be used to guide CI fitting and track auditory cortex development in response to CI use.

Estimation of outer-wall length in optimizing cochlear implantation in malformed inner ears

Estimation of cochlear length is gaining attention in the field of cochlear implants (CIs), mainly for selecting of CI electrode lengths. The currently available tools to estimate the cochlear duct length (CDL) are only valid for normal inner anatomy. However, inner ear malformation (IEM) types are associated with different degrees of cystic apices, limiting the application of CDL equations of normal anatomy inner ear. Therefore, this study aimed to understand the degree to which the outer wall (OW) is observed in different malformation types and to formulate mathematical equations to estimate the OW length (OWL) from cochlear parameters, namely the basal turn diameter (A-value) and width (B-value). Three-dimensional (3D) segmentation of promontory and fluid parts of the inner ear was performed to understand the extent to which the OW is visible to measure the OWL manually. Enlarged vestibular aqueduct syndrome (EVAS) was diagnosed in 37 ears, which consistently showed the extent of the OW to an angular depth of 540°, beyond which the cystic apex starts. Incomplete partition (IP) type I was observed in 30 ears, with the OW extending to only 360° of angular depth. IP type II was observed in 35 ears, with the OW extending to 450° of angular depth. IP type III was identified in 24 ears, with the OW observed for 540° of angular depth. Cavity-type malformations were observed in 36 ears, and circumference was measured in the axial view. A strong positive linear correlation was observed between the manually measured OWL and cochlear parameters for all malformation types analyzed. A multiple linear regression model was applied to formulate mathematical equations, which was further used to create a software application for estimating OWLs in IEM types, using cochlear parameters as inputs.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

P1 and N1 Characteristics in Individuals with Normal Hearing and Hearing Loss, and Cochlear Implant Users: A Pilot Study

Background: It has been reported in many previous studies that the lack of auditory input due to hearing loss (HL) can induce changes in the brain. However, most of these studies have focused on individuals with pre-lingual HL and have predominantly compared the characteristics of those with normal hearing (NH) to cochlear implant (CI) users in children. This study examined the visual and auditory evoked potential characteristics in NH listeners, individuals with bilateral HL, and CI users, including those with single-sided deafness. Methods: A total of sixteen participants (seven NH listeners, four individuals with bilateral sensorineural HL, and five CI users) completed speech testing in quiet and noise and evoked potential testing. For speech testing, the Korean version of the Hearing in Noise Test was used to assess individuals' speech understanding ability in quiet and in noise (noise from the front, +90 degrees, and -90 degrees). For evoked potential testing, visual and auditory (1000 Hz, /ba/, and /da/) evoked potentials were measured. Results: The results showed that CI users understood speech better than those with HL in all conditions except for the noise from +90 and -90 degrees. In the CI group, a decrease in P1 amplitudes was noted across all channels after implantation. The NH group exhibited the highest amplitudes, followed by the HL group, with the CI group (post-CI) showing the lowest amplitudes. In terms of auditory evoked potentials, the smallest amplitude was observed in the pre-CI condition regardless of the type of stimulus. Conclusions: To the best of our knowledge, this is the first study that examined visual and auditory evoked potentials based on various hearing profiles. The characteristics of evoked potentials varied across participant groups, and further studies with CI users are necessary, as there are significant challenges in collecting and analyzing evoked potentials due to artifact issues on the CI side.

Variability in clinicians' prediction accuracy for outcomes of adult cochlear implant users

OBJECTIVE

The variability in outcomes among adult cochlear implant (CI) users poses challenges for clinicians in accurately predicting the benefits of the implant for individual candidates. This study aimed to investigate the accuracy and confidence of clinicians in predicting speech perception outcomes for adult CI users one-year post-implantation.

DESIGN

Participants were presented with comprehensive information on pre-implantation, one-month post-implantation, and six-month post-implantation data for 10 case studies. The cases encompassed a range of one-year post-implantation phoneme scores, from low performers (27%) to high performers (92%). Participants were tasked with predicting the speech perception outcomes for these cases one year after implantation.

STUDY SAMPLE

Forty-one clinicians completed the full outcome prediction survey.

RESULTS

Our findings revealed a significant over-prediction of low performance by clinicians. Interestingly, clinicians tended to predict average performance (73-76% phoneme score) even when provided with information suggesting lower-than-average performance. Most clinicians expressed confidence in their predictions, irrespective of their accuracy.

CONCLUSIONS

Identifying signs of low performance, particularly in the early post-implantation period, can enable clinicians to implement early interventions. Further research into accurate outcome prediction is essential for managing expectations, providing counselling, increasing CI adoption, and optimising clinical care for both high and low performers.

Speech Perception and Quality-of-Life Outcomes in Mandarin-Speaking Postlingual Deaf Adults With Cochlear Implant: Any Difference With the Intonation Language Users?

OBJECTIVE

To evaluate the effects of related factors on long-term speech perception and quality-of-life (QoL) outcomes in postlingual deaf Mandarin-speaking adult cochlear implant (CI) recipients and to assess any differences between tone language and other intonation language CI adult users.

STUDY DESIGN

Retrospective cases review.

SETTING

Tertiary referral center.

PATIENTS

Forty-five adult CI recipients (48 implanted ears).

MAIN OUTCOME MEASURES

Post-CI outcomes were evaluated after follow-ups of more than 24 months using speech perception tests and QoL questionnaires. We analyzed the related factors affecting CI outcomes.

RESULTS

A shorter duration of profound deafness was predictive factors for better post-CI speech perception. Earlier implantation and better performance of vowel scores were predictive of better subjective improvements in social and emotional life. Post-CI vowel scores of over 56% indicated promising improvements in QoL.

CONCLUSION

Shorter duration of deafness could have better post-CI speech perception. Post-CI vowel scores instead of monosyllable words have the more potential to predict the QoL in Mandarin-speaking adult CI recipients.

The Benefits of Cochlear Implantation for Adults: A Systematic Umbrella Review

OBJECTIVES

The uptake of cochlear implants among adults who could benefit (based on pure-tone audiometry) in developed countries is estimated to be less than 10%. Concerns about potential surgical complications, fear of losing residual hearing, and limited awareness about the benefits of this intervention contribute to the low adoption rate. To enhance quality of life and improve the uptake of cochlear implants, it is essential to have a clear understanding of their benefits.

DESIGN

This umbrella review aims to summarize the major benefits of cochlear implant usage in adults, by synthesizing findings from published review articles. A comprehensive search of databases including MEDLINE, EMBASE, PsycINFO, and Google Scholar, was conducted. The search was limited to English-language review articles published between 1990 and 2022, focusing on cochlear implant outcomes in at least 5 adults (aged ≥18 years). Two independent reviewers screened titles, abstracts, and full-text articles, and conducted a quality assessment using the Joanna Briggs Checklist for Systematic Reviews and Research Syntheses.

RESULTS

Forty-two articles were included in this review. There were 15 systematic reviews with meta-analysis, 25 systematic reviews without meta-analysis, and 2 systematic scoping reviews. All 42 articles underwent quality assessment using the Joanna Briggs Institute Checklist for Systematic Reviews and Research Syntheses, of which 40% (n = 17) satisfied 9 out of 11 quality criteria. This umbrella review shows that cochlear implants are associated with improvements in speech perception and recognition as well as improved quality of life and cognition. These benefits are observed in a significant proportion of adults undergoing the procedure, highlighting its effectiveness as a viable intervention for individuals with severe to profound hearing loss.

CONCLUSIONS

The potential benefits of cochlear implantation appear to outweigh the risks and complications associated with the procedure. It is recommended that adults with severe to profound hearing loss in particular, engage in informed discussions with healthcare professionals to consider cochlear implantation as a viable treatment option.

On the Difficulty Predicting Word Recognition Performance After Cochlear Implantation

HYPOTHESIS

Preimplantation word scores cannot reliably predict postimplantation outcomes.

BACKGROUND

To date, there is no model based on preoperative data that can reliably predict the postoperative outcomes of cochlear implantation in the postlingually deafened adult patient.

METHODS

In a group of 228 patients who received a cochlear implant between 2002 and 2021, we tested the predictive power of nine variables (age, etiology, sex, laterality of implantation, preimplantation thresholds and word scores, as well as the design, insertion approach, and angular insertion depth of the electrode array) on postimplantation outcomes. Results of multivariable linear regression analyses were then interpreted in light of data obtained from histopathological analyses of human temporal bones.

RESULTS

Age and etiology were the only significant predictors of postimplantation outcomes. In agreement with many investigations, preimplantation word scores failed to significantly predict postimplantation outcomes. Analysis of temporal bone histopathology suggests that neuronal survival must fall below 40% before word scores in quiet begin to drop. Scores fall steeply with further neurodegeneration, such that only 20% survival can support acoustically driven word scores of 50%. Because almost all cochlear implant implantees have at least 20% of their spiral ganglion neurons (SGNs) surviving, it is expected that most cochlear implant users on average should improve to at least 50% word recognition score, as we observed, even if their preimplantation score was near zero as a result of widespread hair cell damage and the fact that ~50% of their SGNs have likely lost their peripheral axons. These "disconnected" SGNs would not contribute to acoustic hearing but likely remain electrically excitable.

CONCLUSION

The relationship between preimplantation word scores and data describing the survival of SGNs in humans can explain why preimplantation word scores obtained in unaided conditions fail to predict postimplantation outcomes.

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.

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.

Factors Affecting Performance in Adults With Cochlear Implants: A Role for Cognition and Residual Cochlear Function

OBJECTIVE

To evaluate the impact of preoperative and perioperative factors on postlinguistic adult cochlear implant (CI) performance and design a multivariate prediction model.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

PATIENTS AND INTERVENTIONS

Two hundred thirty-nine postlinguistic adult CI recipients.

MAIN OUTCOME MEASURES

Speech-perception testing (consonant-nucleus-consonant [CNC], AzBio in noise +10-dB signal-to-noise ratio) at 3, 6, and 12 months postoperatively; electrocochleography-total response (ECochG-TR) at the round window before electrode insertion.

RESULTS

ECochG-TR strongly correlated with CNC word score at 6 months ( r = 0.71, p < 0.0001). A multivariable linear regression model including age, duration of hearing loss, angular insertion depth, and ECochG-TR did not perform significantly better than ECochG-TR alone in explaining the variability in CNC. AzBio in noise at 6 months had moderate linear correlations with Montreal Cognitive Assessment (MoCA; r = 0.38, p < 0.0001) and ECochG-TR ( r = 0.42, p < 0.0001). ECochG-TR and MoCA and their interaction explained 45.1% of the variability in AzBio in noise scores.

CONCLUSIONS

This study uses the most comprehensive data set to date to validate ECochG-TR as a measure of cochlear health as it relates to suitability for CI stimulation, and it further underlies the importance of the cochlear neural substrate as the main driver in speech perception performance. Performance in noise is more complex and requires both good residual cochlear function (ECochG-TR) and cognition (MoCA). Other demographic, audiologic, and surgical variables are poorly correlated with CI performance suggesting that these are poor surrogates for the integrity of the auditory substrate.

Effect of Cochlear Implant Electrode Insertion Depth on Speech Perception Outcomes: A Systematic Review

Objective

The suitable electrode array choice is broadly discussed in cochlear implantation surgery. Whether to use a shorter electrode length under the aim of structure preservation versus choosing a longer array to achieve a greater cochlear coverage is a matter of debate. The aim of this review is to identify the impact of the insertion depth of a cochlear implant (CI) electrode array on CI users' speech perception outcomes.

Databases Reviewed

PubMed was searched for English-language articles that were published in a peer-reviewed journal from 1997 to 2022.

Methods

A systematic electronic search of the literature was carried out using PubMed to find relevant literature on the impact of insertion depth on speech perception. The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines of reporting. Studies in both, children and adults with pre- or postlingual hearing loss, implanted with a CI were included in this study. Articles written in languages other than English, literature reviews, meta-analyses, animal studies, histopathological studies, or studies pertaining exclusively to imaging modalities without reporting correlations between insertion depth and speech outcomes were excluded. The risk of bias was determined using the "Risk of Bias in Nonrandomized Studies of Interventions" tool. Articles were extracted by 2 authors independently using predefined search terms. The titles and abstracts were screened manually to identify studies that potentially meet the inclusion criteria. The extracted information included: the study population, type of hearing loss, outcomes reported, devices used, speech perception outcomes, insertion depth (linear insertion depth and/or the angular insertion depth), and correlation between insertion depth and the speech perception outcomes.

Results

A total of 215 relevant studies were assessed for eligibility. Twenty-three studies met the inclusion criteria and were analyzed further. Seven studies found no significant correlation between insertion depth and speech perception outcomes. Fifteen found either a significant positive correlation or a positive effect between insertion depth and speech perception. Only 1 study found a significant negative correlation between insertion depth and speech perception outcomes.

Conclusion

Although most studies reported a positive effect of insertion depth on speech perception outcomes, one-third of the identified studies reported no correlation. Thus, the insertion depth must be considered as a contributing factor to speech perception rather than as a major decisive criterion.

Registration

This review has been registered in PROSPERO, the international prospective register of systematic reviews (CRD42021257547), available at https://www.crd.york.ac.uk/PROSPERO/.

Improved Cochlear Implant Performance Estimation Using Tonotopic-Based Electrocochleography

Importance

Cochlear implantation produces remarkable results in postlingual deafness, although auditory outcomes vary. Electrocochleography (ECochG) has emerged as a valuable tool for assessing the cochlear-neural substrate and evaluating patient prognosis.

Objective

To assess whether ECochG-total response (ECochG-TR) recorded at the best-frequency electrode (BF-ECochG-TR) correlates more strongly with speech perception performance than ECochG-TR measured at the round window (RW-ECochG-TR).

Design, Setting, and Participants

This single-center cross-sectional study recruited 142 patients from July 1, 2021, to April 30, 2022, with 1-year follow-up. Exclusions included perilymph suctioning, crimped sound delivery tubes, non-native English speakers, inner ear malformations, nonpatent external auditory canals, or cochlear implantation revision surgery.

Exposures

Cochlear implantation.

Main Outcomes and Measures

Speech perception testing, including the consonant-nucleus-consonant (CNC) words test, AzBio sentences in quiet, and AzBio sentences in noise plus 10-dB signal to noise ratio (with low scores indicating poor performance and high scores indicating excellent performance on all tests), at 6 months postoperatively; and RW-ECochG-TR and BF-ECochG-TR (measured for 250, 500, 1000, and 2000 Hz).

Results

A total of 109 of the 142 eligible postlingual adults (mean [SD] age, 68.7 [15.8] years; 67 [61.5%] male) were included in the study. Both BF-ECochG-TR and RW-ECochG-TR were correlated with 6-month CNC scores (BF-ECochG-TR: r = 0.74; 95% CI, 0.62-0.82; RW-ECochG-TR: r = 0.67; 95% CI, 0.54-0.76). A multivariate model incorporating age, duration of hearing loss, and angular insertion depth did not outperform BF-ECochG-TR or RW-ECochG-TR alone. The BF-ECochG-TR correlation with CNC scores was significantly stronger than the RW-ECochG-TR correlation (r difference = -0.18; 95% CI, -0.31 to -0.01; z = -2.02). More moderate correlations existed between 6-month AzBio scores in noise, Montreal Cognitive Assessment (MoCA) scores (r = 0.46; 95% CI, 0.29-0.60), and BF-ECochG-TR (r = 0.42; 95% CI, 0.22-0.58). MoCA and the interaction between BF-ECochG-TR and MoCA accounted for a substantial proportion of variability in AzBio scores in noise at 6 months (R2 = 0.50; 95% CI, 0.36-0.61).

Conclusions and Relevance

In this case series, BF-ECochG-TR was identified as having a stronger correlation with cochlear implantation performance than RW-ECochG-TR, although both measures highlight the critical role of the cochlear-neural substrate on outcomes. Demographic, audiologic, and surgical factors demonstrated weak correlations with cochlear implantation performance, and performance in noise was found to require a robust cochlear-neural substrate (BF-ECochG-TR) as well as sufficient cognitive capacity (MoCA). Future cochlear implantation studies should consider these variables when assessing performance and related interventions.

The Relationship Between Cochlear Implant Speech Perception Outcomes and Electrophysiological Measures of the Electrically Evoked Compound Action Potential

OBJECTIVE

This study assessed the relationship between electrophysiological measures of the electrically evoked compound action potential (eCAP) and speech perception scores measured in quiet and in noise in postlingually deafened adult cochlear implant (CI) users. It tested the hypothesis that how well the auditory nerve (AN) responds to electrical stimulation is important for speech perception with a CI in challenging listening conditions.

DESIGN

Study participants included 24 postlingually deafened adult CI users. All participants used Cochlear Nucleus CIs in their test ears. In each participant, eCAPs were measured at multiple electrode locations in response to single-pulse, paired-pulse, and pulse-train stimuli. Independent variables included six metrics calculated from the eCAP recordings: the electrode-neuron interface (ENI) index, the neural adaptation (NA) ratio, NA speed, the adaptation recovery (AR) ratio, AR speed, and the amplitude modulation (AM) ratio. The ENI index quantified the effectiveness of the CI electrodes in stimulating the targeted AN fibers. The NA ratio indicated the amount of NA at the AN caused by a train of constant-amplitude pulses. NA speed was defined as the speed/rate of NA. The AR ratio estimated the amount of recovery from NA at a fixed time point after the cessation of pulse-train stimulation. AR speed referred to the speed of recovery from NA caused by previous pulse-train stimulation. The AM ratio provided a measure of AN sensitivity to AM cues. Participants' speech perception scores were measured using Consonant-Nucleus-Consonant (CNC) word lists and AzBio sentences presented in quiet, as well as in noise at signal-to-noise ratios (SNRs) of +10 and +5 dB. Predictive models were created for each speech measure to identify eCAP metrics with meaningful predictive power.

RESULTS

The ENI index and AR speed individually explained at least 10% of the variance in most of the speech perception scores measured in this study, while the NA ratio, NA speed, the AR ratio, and the AM ratio did not. The ENI index was identified as the only eCAP metric that had unique predictive power for each of the speech test results. The amount of variance in speech perception scores (both CNC words and AzBio sentences) explained by the eCAP metrics increased with increased difficulty under the listening condition. Over half of the variance in speech perception scores measured in +5 dB SNR noise (both CNC words and AzBio sentences) was explained by a model with only three eCAP metrics: the ENI index, NA speed, and AR speed.

CONCLUSIONS

Of the six electrophysiological measures assessed in this study, the ENI index is the most informative predictor for speech perception performance in CI users. In agreement with the tested hypothesis, the response characteristics of the AN to electrical stimulation are more important for speech perception with a CI in noise than they are in quiet.

Cognitive Performance, Sociodemographic Factors, Pure-Tone Audiometry, and their Association with Speech Discrimination: A Prospective Population-Based Study of 1,061 Older Adults

OBJECTIVE

Hearing loss is increasingly recognized as a chronic disease state with important health sequelae. Although considered a central component of routine audiometric testing, the degree to which various patient factors influence speech discrimination is poorly characterized to date. The primary objective of the current work was to describe associations of cognitive performance, sociodemographic factors, and pure-tone audiometry with speech discrimination in older adults.

STUDY DESIGN

Prospective study.

SETTING

Olmsted County, Minnesota.

PATIENTS

There were 1,061 study participants 50 years or older at enrollment in the population-based Mayo Clinic Study of Aging between November 2004 and December 2019 who underwent formal audiometric and cognitive testing included in the current investigation.

MAIN OUTCOME MEASURES

The primary outcome measure was word recognition scores (WRSs; measured as <100% vs 100% as well as continuous), with pure-tone averages (PTAs; 0.5, 1, 2, and 3 kHz), age, sex, years of education, state area deprivation index (ADI) quintiles, and global cognition z scores as explanatory features.

RESULTS

The mean (SD) age among the 1,061 participants was 76 (9) years with 528 (50%) males. Participant age [OR (95% CI) for a 10-year increase of 1.8 (1.4-2.3), p < 0.001], male sex [OR = 2.6 (1.9-3.7), p < 0.001], and PTA [OR for a 10-dB hearing loss increase of 2.4 (2.1-2.8), p < 0.001] were all significantly associated with <100% WRSs, with the greatest explanatory ability attributable to the PTA. Years of education ( p = 0.9), state ADI quintile ( p = 0.6), and global cognitive performance ( p = 0.2) were not associated with WRS. The multivariable model demonstrated strong predictive ability for less than perfect WRSs, with a c index of 0.854. Similar results were seen for WRSs analyzed as continuous, with the multivariable model resulting in an R2 value of 0.433.

CONCLUSIONS

Although PTA exhibited the greatest influence on speech discrimination, advancing age and male sex both independently increased the likelihood of having worse speech discrimination among older adults, even after accounting for years of education, neighborhood-level socioeconomic disadvantage, and cognitive function. These findings help identify patient factors that can be instrumental when designing screening programs for adult-onset hearing loss.

The Impact of Patient Factors on Objective Cochlear Implant Verification Using Acoustic Cortical Auditory-Evoked Potentials

INTRODUCTION

Hearing loss is a major global public health issue that negatively impacts quality of life, communication, cognition, social participation, and mental health. The cochlear implant (CI) is the most efficacious treatment for severe-to-profound sensorineural hearing loss. However, variability in outcomes remains high among CI users. Our previous research demonstrated that the existing subjective methodology of CI programming does not consistently produce optimal stimulation for speech perception, thereby limiting the potential for CI users to derive the maximum device benefit to achieve their peak potential. We demonstrated the benefit of utilising the objective method of measuring auditory-evoked cortical responses to speech stimuli as a reliable tool to guide and verify CI programming and, in turn, significantly improve speech perception performance. The present study was designed to investigate the impact of patient- and device-specific factors on the application of acoustically-evoked cortical auditory-evoked potential (aCAEP) measures as an objective clinical tool to verify CI mapping in adult CI users with bilateral deafness (BD).

METHODS

aCAEP responses were elicited using binaural peripheral auditory stimulation for four speech tokens (/m/, /g/, /t/, and /s/) and recorded by HEARLab™ software in adult BD CI users. Participants were classified into groups according to subjective or objective CI mapping procedures to elicit present aCAEP responses to all four speech tokens. The impact of patient- and device-specific factors on the presence of aCAEP responses and speech perception was investigated between participant groups.

RESULTS

Participants were categorised based on the presence or absence of the P1-N1-P2 aCAEP response to speech tokens. Out of the total cohort of adult CI users (n = 132), 63 participants demonstrated present responses pre-optimisation, 37 participants exhibited present responses post-optimisation, and the remaining 32 participants either showed an absent response for at least one speech token post-optimisation or did not accept the optimised CI map adjustments. Overall, no significant correlation was shown between patient and device-specific factors and the presence of aCAEP responses or speech perception scores.

CONCLUSION

This study reinforces that aCAEP measures offer an objective, non-invasive approach to verify CI mapping, irrespective of patient or device factors. These findings further our understanding of the importance of personalised CI rehabilitation through CI mapping to minimise the degree of speech perception variation post-CI and allow all CI users to achieve maximum device benefit.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2362-2370, 2023.

Early Datalogging Predicts Cochlear Implant Performance: Building a Recommendation for Daily Device Usage

OBJECTIVE

To quantify the effect of datalogging on speech recognition scores and time to achievement for a "benchmark" level of performance within the first year, and to provide a data-driven recommendation for minimum daily cochlear implant (CI) device usage to better guide patient counseling and future outcomes.

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary referral center.

PATIENTS

Three hundred thirty-seven adult CI patients with data logging and speech recognition outcome data who were implanted between August 2015 and August 2020.

MAIN OUTCOME MEASURES

Processor datalogging, speech recognition scores, achievement of "benchmark speech recognition performance" defined as 80% of the median score for speech recognition outcomes at our institution.

RESULTS

The 1-month datalogging measure correlated positively with word and sentences scores at 1, 3, 6, and 12 months postactivation. Compared with age, sex, and preoperative performance, datalogging was the largest predictive factor of benchmark achievement on multivariate analysis. Each hour/day increase of device usage at 1 month resulted in a higher likelihood of achieving benchmark consonant-nucleus-consonant and AzBio scores within the first year (odds ratio = 1.21, p < 0.001) as well as earlier benchmark achievement. Receiver operating characteristic curve analysis identified the optimal data logging threshold at an average of 12 hours/day.

CONCLUSIONS

Early CI device usage, as measured by 1-month datalogging, predicts benchmark speech recognition achievement in adults. Datalogging is an important predictor of CI performance within the first year postimplantation. These data support the recommended daily CI processor utilization of at least 12 hours/day to achieve optimal speech recognition performance for most patients.

Listening efficiency in adult cochlear-implant users compared with normally-hearing controls at ecologically relevant signal-to-noise ratios

Introduction

Due to having to work with an impoverished auditory signal, cochlear-implant (CI) users may experience reduced speech intelligibility and/or increased listening effort in real-world listening situations, compared to their normally-hearing (NH) peers. These two challenges to perception may be usefully integrated in a measure of listening efficiency: conceptually, the amount of accuracy achieved for a certain amount of effort expended.

Methods

We describe a novel approach to quantifying listening efficiency based on the rate of evidence accumulation toward a correct response in a linear ballistic accumulator (LBA) model of choice decision-making. Estimation of this objective measure within a hierarchical Bayesian framework confers further benefits, including full quantification of uncertainty in parameter estimates. We applied this approach to examine the speech-in-noise performance of a group of 24 CI users (M age: 60.3, range: 20-84 years) and a group of 25 approximately age-matched NH controls (M age: 55.8, range: 20-79 years). In a laboratory experiment, participants listened to reverberant target sentences in cafeteria noise at ecologically relevant signal-to-noise ratios (SNRs) of +20, +10, and +4 dB SNR. Individual differences in cognition and self-reported listening experiences were also characterised by means of cognitive tests and hearing questionnaires.

Results

At the group level, the CI group showed much lower listening efficiency than the NH group, even in favourable acoustic conditions. At the individual level, within the CI group (but not the NH group), higher listening efficiency was associated with better cognition (i.e., working-memory and linguistic-closure) and with more positive self-reported listening experiences, both in the laboratory and in daily life.

Discussion

We argue that listening efficiency, measured using the approach described here, is: (i) conceptually well-motivated, in that it is theoretically impervious to differences in how individuals approach the speed-accuracy trade-off that is inherent to all perceptual decision making; and (ii) of practical utility, in that it is sensitive to differences in task demand, and to differences between groups, even when speech intelligibility remains at or near ceiling level. Further research is needed to explore the sensitivity and practical utility of this metric across diverse listening situations.

Cochlear implants: the effects of age on outcomes

INTRODUCTION

Cochlear implants (CIs) provide access to sound for children and adults who do not receive adequate benefit from hearing aids. Age at implantation is known to affect outcomes across the lifespan.

AREAS COVERED

The effects of age on CI outcomes are examined for infants, children, adolescents, and older adults. A variety of outcome measures are considered, including speech perception, language, cognition, and quality of life measures.

EXPERT OPINION/COMMENTARY

For those meeting candidacy criteria, CIs are beneficial at any age. In general, younger age is related to greater benefit when considering pre-lingual deafness. Other factors such as additional disabilities, may mitigate this effect. Post-lingually deafened adults demonstrate similar benefit regardless of age, though the oldest individuals (80+) may see smaller degrees of improvement from preoperative scores. Benefit can be measured in many ways, and the areas of greatest benefit may vary based on age: young children appear to see the greatest effects of age at implantation on language measures, whereas scores on cognitive measures appear to be most impacted for the oldest population. Future research should consider implantation at extreme ages (5-9 months or > 90 years), unconventional measures of CI benefit including qualitative assessments, and longitudinal designs.

Impact of Anticholinergic Medications on Speech Perception Performance after Cochlear Implantation

OBJECTIVE

To identify and characterize the impact of anticholinergic medications, which have known adverse effects on cognition in older adults, on speech perception after cochlear implantation.

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary referral center.

SUBJECT POPULATION

Adult patients who underwent cochlear implantation between January 2010 and September 2020 with speech perception scores at 3, 6, and 12 months.

INTERVENTIONS

Anticholinergic burden of patients' prescribed medications.

MAIN OUTCOME MEASURES

AzBio speech perception scores after implantation.

RESULTS

One hundred twenty-six patients had documented AzBio in quiet speech perception score at all three postactivation time points. Patients were divided into three groups by anticholinergic burden (ACB) score, including ACB = 0 (90 patients), 1 (23 patients), and ≥2 (13 patients). There was no statistically significant difference between ACB groups in audiologic performance at candidacy testing ( p = 0.77) or at 3 months after implantation ( p = 0.13). Beginning at 6 months, a lower mean AzBio was seen in patients with higher ACB scores (68% ACB = 0; 62% ACB = 1; 48.1% ACB ≥ 2; p = 0.03). At 12 months, there were further differences between the groups (71.0% ACB = 0, 69.5% ACB = 1, 48.0% ACB ≥2, p < 0.01). Controlling for the effects of age using multivariate linear regression showed persistent effects of ACB score on learning-related AzBio improvements. Comparatively, the negative impact of a single ACB score point was equivalent to nearly 10 years of aging ( p = 0.03).

CONCLUSIONS

Increased ACB is associated with worse speech perception scores after cochlear implantation, an effect that persists even when accounting for patient age, suggesting that these medications may have cognitive and learning effects that reduce cochlear implant performance.

Responsible Imputation of Missing Speech Perception Testing Data & Analysis of 4,739 Observations and Predictors of Performance

OBJECTIVE

To address outcome heterogeneity in cochlear implant (CI) research, we built imputation models using multiple imputation by chained equations (MICEs) and K-nearest neighbors (KNNs) to convert between four common open-set testing scenarios: Consonant-Nucleus-Consonant word (CNCw), Arizona Biomedical (AzBio) in quiet, AzBio +5, and AzBio +10. We then analyzed raw and imputed data sets to evaluate factors affecting CI outcome variability.

STUDY DESIGN

Retrospective cohort study of a national CI database (HERMES) and a nonoverlapping single-institution CI database.

SETTING

Multi-institutional (32 CI centers).

PATIENTS

Adult CI recipients (n = 4,046 patients).

MAIN OUTCOME MEASURES

Mean absolute error (MAE) between imputed and observed speech perception scores.

RESULTS

Imputation models of preoperative speech perception measures demonstrate a MAE of less than 10% for feature triplets of CNCw/AzBio in quiet/AzBio +10 (MICE: MAE, 9.52%; 95% confidence interval [CI], 9.40-9.64; KNN: MAE, 8.93%; 95% CI, 8.83-9.03) and AzBio in quiet/AzBio +5/AzBio +10 (MICE: MAE, 8.85%; 95% CI, 8.68-9.02; KNN: MAE, 8.95%; 95% CI, 8.74-9.16) with one feature missing. Postoperative imputation can be safely performed with up to four of six features missing in a set of CNCw and AzBio in quiet at 3, 6, and 12 months postcochlear implantation using MICE (MAE, 9.69%; 95% CI, 9.63-9.76). For multivariable analysis of CI performance prediction, imputation increased sample size by 72%, from 2,756 to 4,739, with marginal change in adjusted R2 (0.13 raw, 0.14 imputed).

CONCLUSIONS

Missing data across certain sets of common speech perception tests may be safely imputed, enabling multivariate analysis of one of the largest CI outcomes data sets to date.

Surgical tumour excision of pleomorphic adenoma of submandibular salivary gland: A case report and literature review

INTRODUCTION AND IMPORTANCE

Pleomorphic adenoma is a benign tumour commonly found in salivary glands and surgical excision is the preferred treatment.

CASE PRESENTATION

This case report describes a 37-year-old male patient who was psychologically affected, socially stigmatised and economically jeopardised, underwent successful surgical excision of a pleomorphic adenoma in the submandibular gland. The procedure involved making a lower submandibular incision through the skin, followed by blunt dissection to approach the tumour, where the whole gland was involved and excised. Haemostasis was achieved through compression, transfixing, and under-running sutures. The patient recovered well without any complications and was discharged with a good outlook.

CLINICAL DISCUSSION

Proper diagnosis and using proper surgical techniques is essential to ensure favourable outcomes. Early diagnosis and prompt management of pleomorphic adenoma are crucial to prevent complications and improve the patient's quality of life.

CONCLUSION

Surgical tumour excision is a safe and effective treatment for pleomorphic adenoma in the submandibular gland. Successful surgery has significant changes in the quality of life of the patient.

Association of Cognitive Impairment Screening Scores With Improvements in Speech Recognition and Quality of Life After Cochlear Implantation

Importance

Many cochlear implant centers screen patients for cognitive impairment as part of the evaluation process, but the utility of these scores in predicting cochlear implant outcomes is unknown.

Objective

To determine whether there is an association between cognitive impairment screening scores and cochlear implant outcomes.

Design, Setting, and Participants

Retrospective case series of adult cochlear implant recipients who underwent preoperative cognitive impairment screening with the Montreal Cognitive Assessment (MoCA) from 2018 to 2020 with 1-year follow-up at a single tertiary cochlear implant center. Data analysis was performed on data from January 2018 through December 2021.

Exposures

Cochlear implantation.

Main Outcomes and Measures

Preoperative MoCA scores and mean (SD) improvement (aided preoperative to 12-month postoperative) in Consonant-Nucleus-Consonant phonemes (CNCp) and words (CNCw), AzBio sentences in quiet (AzBio Quiet), and Cochlear Implant Quality of Life-35 (CIQOL-35) Profile domain and global scores.

Results

A total of 52 patients were included, 27 (52%) of whom were male and 46 (88%) were White; mean (SD) age at implantation was 68.2 (13.3) years. Twenty-three (44%) had MoCA scores suggesting mild and 1 (2%) had scores suggesting moderate cognitive impairment. None had been previously diagnosed with cognitive impairment. There were small to medium effects of the association between 12-month postoperative improvement in speech recognition measures and screening positive or not for cognitive impairment (CNCw mean [SD]: 48.4 [21.9] vs 38.5 [26.6] [d = -0.43 (95% CI, -1.02 to 0.16)]; AzBio Quiet mean [SD]: 47.5 [34.3] vs 44.7 [33.1] [d = -0.08 (95% CI, -0.64 to 0.47)]). Similarly, small to large effects of the associations between 12-month postoperative change in CIQOL-35 scores and screening positive or not for cognitive impairment were found (global: d = 0.32 [95% CI, -0.59 to 1.23]; communication: d = 0.62 [95% CI, -0.31 to 1.54]; emotional: d = 0.26 [95% CI, -0.66 to 1.16]; entertainment: d = -0.005 [95% CI, -0.91 to 0.9]; environmental: d = -0.92 [95% CI, -1.86 to 0.46]; listening effort: d = -0.79 [95% CI, -1.65 to 0.22]; social: d = -0.51 [95% CI, -1.43 to 0.42]).

Conclusions and Relevance

In this case series, screening scores were not associated with the degree of improvement of speech recognition or patient-reported outcome measures after cochlear implantation. Given the prevalence of screening positive for cognitive impairment before cochlear implantation, preoperative screening can be useful for early identification of potential cognitive decline. These findings support that screening scores may have a limited role in preoperative counseling of outcomes and should not be used to limit candidacy.

Association of Aging and Cognition With Complex Speech Understanding in Cochlear-Implanted Adults: Use of a Modified National Institutes of Health (NIH) Toolbox Cognitive Assessment

Importance

The association between cognitive function and outcomes in cochlear implant (CI) users is not completely understood, partly because some cognitive tests are confounded by auditory status. It is important to determine appropriate cognitive tests to use in a cohort of CI recipients.

Objective

To provide proof-of-concept for using an adapted version of the National Institutes of Health (NIH) Toolbox Cognition Battery in a cohort of patients with CIs and to explore how hearing in noise with a CI is affected by cognitive status using the adapted test.

Design, Setting, and Participants

In this prognostic study, participants listened to sentences presented in a speech-shaped background noise. Cognitive tests consisted of 7 subtests of the NIH Toolbox Cognition Battery that were adapted for hearing impaired individuals by including written instructions and visual stimuli. Participants were prospectively recruited from and evaluated at a tertiary medical center. All participants had at least 6 months' experience with their CI.

Main Outcomes and Measures

The main outcomes were performance on the adapted cognitive test and a speech recognition in noise task.

Results

Participants were 20 adult perilingually or postlingually deafened CI users (50% male participants; median [range] age, 66 [26-80] years old). Performance on a sentence recognition in noise task was negatively associated with the chronological age of the listener (R2 = 0.29; β = 0.16; standard error, SE = 0.06; t = 2.63; 95% confidence interval, 0.03-0.27). Testing using the adapted version of the NIH Toolbox Cognition Battery revealed that a test of processing speed was also associated with performance, using a standardized score that accounted for contributions of other demographic factors (R2 = 0.28; 95% confidence interval, -0.42 to -0.05).

Conclusions and Relevance

In this prognostic study, older CI users showed poorer performance on a sentence-in-noise test compared with younger users. This poorer performance was correlated with a cognitive deficit in processing speed when cognitive function was assessed using a test battery adapted for participants with hearing loss. These results provide initial proof-of-concept results for using a standardized and adapted cognitive test battery in CI recipients.

Exploring neurocognitive factors and brain activation in adult cochlear implant recipients associated with speech perception outcomes-A scoping review

Background

Cochlear implants (CIs) are considered an effective treatment for severe-to-profound sensorineural hearing loss. However, speech perception outcomes are highly variable among adult CI recipients. Top-down neurocognitive factors have been hypothesized to contribute to this variation that is currently only partly explained by biological and audiological factors. Studies investigating this, use varying methods and observe varying outcomes, and their relevance has yet to be evaluated in a review. Gathering and structuring this evidence in this scoping review provides a clear overview of where this research line currently stands, with the aim of guiding future research.

Objective

To understand to which extent different neurocognitive factors influence speech perception in adult CI users with a postlingual onset of hearing loss, by systematically reviewing the literature.

Methods

A systematic scoping review was performed according to the PRISMA guidelines. Studies investigating the influence of one or more neurocognitive factors on speech perception post-implantation were included. Word and sentence perception in quiet and noise were included as speech perception outcome metrics and six key neurocognitive domains, as defined by the DSM-5, were covered during the literature search (Protocol in open science registries: 10.17605/OSF.IO/Z3G7W of searches in June 2020, April 2022).

Results

From 5,668 retrieved articles, 54 articles were included and grouped into three categories using different measures to relate to speech perception outcomes: (1) Nineteen studies investigating brain activation, (2) Thirty-one investigating performance on cognitive tests, and (3) Eighteen investigating linguistic skills.

Conclusion

The use of cognitive functions, recruiting the frontal cortex, the use of visual cues, recruiting the occipital cortex, and the temporal cortex still available for language processing, are beneficial for adult CI users. Cognitive assessments indicate that performance on non-verbal intelligence tasks positively correlated with speech perception outcomes. Performance on auditory or visual working memory, learning, memory and vocabulary tasks were unrelated to speech perception outcomes and performance on the Stroop task not to word perception in quiet. However, there are still many uncertainties regarding the explanation of inconsistent results between papers and more comprehensive studies are needed e.g., including different assessment times, or combining neuroimaging and behavioral measures.

Systematic review registration

https://doi.org/10.17605/OSF.IO/Z3G7W.

Vestibular Implantation Can Work Even After More Than 20 Years of Bilateral Vestibular Hypofunction

OBJECTIVE

To determine whether prosthetic stimulation delivered via a vestibular implant can elicit artificial sensation of head movement despite long (23-yr) duration adult-onset ototoxic bilateral vestibular hypofunction (BVH).

STUDY DESIGN

Case report.

SETTING

Tertiary care center as part of a first-in-human clinical trial.

PATIENTS

One.

INTERVENTIONS

Unilateral vestibular implantation with an investigational multichannel vestibular implant in a 55-year-old man with a well-documented 23-year history of aminoglycoside-induced BVH.

MAIN OUTCOME MEASURES

Electrically evoked vestibulo-ocular reflexes (eeVOR).

RESULTS

Vestibular implant stimulation can drive stimulus-aligned eeVOR and elicit a vestibular percept 23 years after the onset of bilateral vestibulopathy. Prosthetic stimulation targeting individual semicircular canals elicited eye movements that approximately aligned with each targeted canal's axis. The magnitude of the eeVOR response increased with increasing stimulus current amplitude. Response alignment and magnitude were similar to those observed for implant recipients who underwent vestibular implantation less than 10 years after BVH onset. Responses were approximately stable for 18 months of continuous device use (24 h/d except during sleep).

CONCLUSIONS

Vestibular implantation and prosthetic electrical stimulation of semicircular canal afferent nerves can drive canal-specific eye movement responses more than 20 years after the onset of ototoxic vestibular hypofunction.

Comprehensive Prediction Model, Including Genetic Testing, for the Outcomes of Cochlear Implantation

OBJECTIVES

Despite growing interest in the genetic contribution to cochlear implant (CI) outcomes, only a few studies with limited samples have examined the association of CI outcomes with genetic etiologies. We analyzed CI outcomes using known predictors and genetic testing results to obtain a comprehensive understanding of the impact of genetic etiologies.

DESIGN

We retrospectively reviewed the medical records and images of patients who underwent cochlear implantation and genetic testing at a single tertiary medical institution, between May 2008 and December 2020. After excluding those whose speech test results were unavailable, and those in whom the implant was removed due to complications, such as infection or device failure, 203 patients were included in this study. The participants were categorized into adult (≥19 years), child (2-18 years), and infant (<24 months) groups. Outcomes were measured based on categories of auditory perception, monosyllable, disyllable, and sentence scores. For the infant group, the Infant-Toddler Meaningful Auditory Integration Scale score was used.

RESULTS

Among the 203 participants, a causative genetic variant was identified in 117 (57.6%) individuals. The presence of a causative variant was significantly associated with better CI outcomes in the infant group (β = 0.23; 95% confidence interval, 0.01 to 0.47; p = 0.044), but not in the child and adult groups. In the genetically confirmed patients without cochlear malformation, genetic variants involving the spiral ganglion was a poor prognostic factor in the child group (β = -57.24; 95% confidence interval, -90.63 to -23.75; p = 0.004).

CONCLUSIONS

The presence of known genetic etiology of hearing loss was associated with better CI outcomes in the infant group, but not in the child and adult groups. A neural-type genetic variant was a poor prognostic factor in the genetically diagnosed child subgroup without cochlear malformation. Careful genetic counseling should be performed before cochlear implantation.

Differential auditory cortical development in left and right cochlear implanted children

Unilateral aural stimulation has been shown to cause massive cortical reorganization in brain with congenital deafness, particularly during the sensitive period of brain development. However, it is unclear which side of stimulation provides most advantages for auditory development. The left hemisphere dominance of speech and linguistic processing in normal hearing adult brain has led to the assumption of functional and developmental advantages of right over left implantation, but existing evidence is controversial. To test this assumption and provide evidence for clinical choice, we examined 34 prelingually deaf children with unilateral cochlear implants using near-infrared spectroscopy. While controlling for age of implantation, residual hearing, and dominant hand, cortical processing of speech showed neither developmental progress nor influence of implantation side weeks to months after implant activation. In sharp contrast, for nonspeech (music signal vs. noise) processing, left implantation showed functional advantages over right implantation that were not yet discernable using clinical, questionnaire-based outcome measures. These findings support the notion that the right hemisphere develops earlier and is better preserved from adverse environmental influences than its left counterpart. This study thus provides, to our knowledge, the first evidence for differential influences of left and right auditory peripheral stimulation on early cortical development of the human brain.

Development and Implementation of the Cochlear Implant Quality of Life (CIQOL) Functional Staging System

OBJECTIVES

The purpose of this study is to develop and implement a functional staging system using the Cochlear Implant Quality of Life (CIQOL) framework. The CIQOL-35 Profile was developed and validated following a rigorous research design and found to be more comprehensive and psychometrically sound than previous patient-reported outcome measures (PROMs) applied to adult CI users. However, interpreting the CIQOL-35 Profile (and all PROMs) relative to real-world functioning remains difficult for patients and clinicians, which limits the capacity of PROMs to direct clinical care. To address this limitation, a functional staging system based on PROM scores was developed to provide detailed descriptions of patients' self-reported abilities (clinical vignettes) without sacrificing the inherent value of the psychometrically derived scores. The current study (1) creates an evidence-based CIQOL functional staging system using advanced psychometric techniques, (2) confirms the clarity and meaningfulness of the staging system with patients, and (3) implements the staging system to measure CIQOL stage progression using data from a longitudinal study design.

METHODS

Item response theory (IRT) analyses of CIQOL-35 Profile data from 705 experienced adult CI users and expert opinion were used to determine the cut-scores that separated adjacent stages for the six CIQOL-35 domains (communication, emotional, entertainment, environment, listening effort, and social). The research team then created clinical vignettes based on item response patterns for each stage. Semi-structured key informant interviews were conducted with 10 adult CI users to determine the clarity and meaningfulness of the CIQOL stages and associated clinical vignettes. Finally, we prospectively collected CIQOL-35 Profile scores from 42 CI users prior to cochlear implantation and then at 3- and 6-months post-CI activation to measure CIQOL stage progression.

RESULTS

Psychometric analyses identified five statistically distinct stages for the communication domain and three stages for all other domains. Using IRT analysis results for guidance, research team members independently identified the cut-scores that represented transitions between the functional stages for each domain with excellent agreement (κ = 0.98 [95% confidence interval 0.96-0.99]). Next, the key informant interviews revealed that CI users found the clinical vignettes to be clear and only minor changes were required. Participants also agreed that stage progression represented meaningful improvements in functional abilities. Finally, 88.1% of 42 patients in the prospective cohort (n = 37) improved from pre-CI functional stage by at least one functional stage in one or more domains. The communication domain had the greatest number of patients improve by one or more stages (59.5%) and the social domain the fewest (25.6%). There was also a trend for less improvement at 3- and 6-months post-CI activation for patients at higher pre-CI functional stages, even though higher stages were achievable.

CONCLUSION

The new CIQOL functional staging system provides an evidence-based understanding of the real-world functional abilities of adult CI users from pre-CI to 3- to 6-months post-CI activation across multiple domains. In addition, study results provide the proportion of CI users in each stage at each timepoint. Results can be used during discussions of expectations with potential CI users to provide enhanced insight regarding realistic outcomes and the anticipated timing for improvements. The use of the CIQOL functional staging system also presents an opportunity to develop individualized goal-based rehabilitation strategies that target barriers to stage advancement faced by CI users.

LEVEL OF EVIDENCE

2 Laryngoscope, 132:S1-S13, 2022.

Understanding Patient Expectations Before Implantation Using the Cochlear Implant Quality of Life-Expectations Instrument

Importance

Previous research suggests that clinicians view realistic patient expectations as the most important nonaudiological factor in the decision to proceed with a cochlear implant (CI). However, clinicians have few data to determine whether patients' outcome expectations are realistic.

Objective

To address this unmet clinical need through the development and psychometric analysis of a new patient-reported outcome measure, the CI Quality of Life (CIQOL) Expectations.

Design, Setting, and Participants

This cross-sectional study was conducted at a tertiary CI center from February 26, 2020, to August 31, 2021. First, a team comprising 2 CI audiologists, a CI surgeon, a hearing scientist, and 2 psychometricians with experience in instrument development converted all items from the CIQOL-35 Profile instrument into statements reflecting expected outcomes. Then, cognitive interviews with 20 potential CI users assessed the clarity and comprehensiveness of the new instrument. Next, responses to the CIQOL-Expectations instrument for 131 potential adult CI candidates were psychometrically analyzed using confirmatory factor analysis and item response theory. Finally, degree to which patient expectations changed from before to after and their CI evaluation appointments was measured.

Intervention

The CIQOL-Expectations instrument.

Results

Of 178 participants, 85 (47.8%) were female, and there was 1 (0.6%) Asian, 26 (14.6%) Black or African American, 1 (0.6%) Latinx, and 150 (84.3%) White individuals. No major content or grammar changes were identified during the cognitive interviews. Overall, all CIQOL domains demonstrated adequate to strong psychometric properties. Several domains did not meet all a priori established indicators of model fit or ability to separate CI users based on response patterns, but all met most indicators. Potential CI users demonstrated the highest mean (SD) expectation scores for the environment (70.2 [20.8]) and social (68.4 [18.0]) domains. In addition, the entertainment (20 [15.3%]) and environment (31 [24.4%]) domains had the highest percentage of patients with expectation scores of 100. Yet, normative CIQOL-35 Profile data from experienced CI users suggested few patients obtain this high degree of functional benefit after implant.

Conclusions and Relevance

The results of this cross-sectional study suggest that the CIQOL-Expectations instrument may provide an opportunity to assess potential CI users' expected outcomes using modification of an established CIQOL instrument and a patient-centered framework. The included items and domains reflect real-world functional abilities valued by CI users and may provide opportunities for an evidence-based shared decision-making approach to the CI evaluation process. With this instrument, clinicians can compare individual patients' pre-CI outcome expectations with established normative data and provide appropriate counseling.

How the Past Shapes the Future and What to Do About It: A Discussion at CI 2021 Virtual With Panelists: Teresa Caraway, Ph.D., C.C.C.-S.L.P.; Cliff Megerian, M.D.; Debara Tucci, M.D., M.S., M.B.A.; Peter Thomas, J.D.; Jason Wigand, Au.D

ABSTRACT

This report summarizes the highlights of a lively discussion between leaders in the cochlear implant (CI) field who also bring significant leadership experience at the practice and health system levels, as well as policy and research perspectives. The discussion revealed several areas in which established patterns of practice should be reconsidered to facilitate wider acceptance of the CI as part of an integrated continuum of hearing healthcare. The importance of continued innovation to advance outcomes, lower cost, and increase access was emphasized. Trends in healthcare funding, which increasingly reward quality at lower cost, will also challenge longstanding assumptions that have influenced program design. Proactive efforts that pursue consistent value in the episode of surgical care while establishing innovative delivery models for audiological and rehabilitation services are the best hope for a future of equitable access and expanding impact.

Are Speech Perception Scores in Cochlear Implant Recipients Consistent Across Different Tests?

OBJECTIVE

Cochlear implant (CI) candidacy and postoperative outcomes are assessed using sets of speech perception tests that vary from center to center, limiting comparisons across institutions and time periods. The objective of this study was to determine if scores on one speech perception test could be reliably predicted from scores on another test.

STUDY DESIGN

Arizona Biomedical (AzBio) Sentence Test, Consonant-Nucleus-Consonant word (CNCw), and Hearing in Noise Test (HINT) scores in quiet for the implanted ear were collected for individuals who received a CI between 1985 and 2019. Scores collected during the same testing session were analyzed using Bland-Altman plots to assess agreement between testing methods. Simple linear regression with logit transformation was used to generate predictive functions and 95% confidence intervals for expected mean and individual scores.

SETTING

Single academic medical center.

PATIENTS

A total of 1,437 individuals with a median age of 59.9 years (range, 18-95 yr) and 46% (654 of 1,437) male.

INTERVENTIONS

N.A.

MAIN OUTCOME MEASURES

Agreement as a function of test score, mean, variance, and correlation coefficients.

RESULTS

A total of 2,052 AzBio/CNCw, 525 AzBio/HINT, and 7,187 CNCw/HINT same-session score pairings were identified. Pairwise test comparisons demonstrated limited agreement between different tests performed in the same session, and a score correlation between different speech tests revealed large variances.

CONCLUSION

Transformation functions between test batteries were predictive of mean scores but performed poorly for prediction of individual scores. Point-wise comparisons of scores across CI test batteries should be used with caution in clinical and research settings.

Normative Cochlear Implant Quality of Life (CIQOL)-35 Profile and CIQOL-10 Global Scores for Experienced Cochlear Implant Users from a Multi-Institutional Study

OBJECTIVE

Although adult cochlear implant (CI) outcomes have primarily focused on speech recognition scores, the rigorous development of a CI-specific patient-reported outcome measure provides an opportunity for a more comprehensive and ecologically valid approach to measure the real-world functional abilities of adult CI users. Here, we report for the first time normative Cochlear Implant Quality of Life (CIQOL)-35 Profile and global scores and variance for a large, multi-institutional sample of adult CI users.

STUDY DESIGN

Cross-sectional study design.

SETTING

CI centers in the United States.

PATIENTS

Seven hundred five adults with bilateral moderate to profound hearing loss with at least 1 year of CI use.

INTERVENTIONS

Cochlear implantation.

MAIN OUTCOME MEASURES

CIQOL-35 Profile and CIQOL-10 Global scores.

RESULTS

During the development of the CIQOL instruments, 1,000 CI users from all regions of the United States were invited to participate in studies. Of these, 705 (70.5%) completed all portions of the study, and their data are reported here. Mean CIQOL domain scores were highest (indicating better function) for the emotional and social domains and lowest for listening effort. The entertainment and social domains demonstrated the widest distribution of scores and largest standard deviations, indicating greatest variability in function. Overall, there were minimal ceiling and floor effects for all domains.

CONCLUSION

Normative scores from a large sample of experienced adult CI users are consistent with clinical observations, showing large differences in functional abilities and large variability. Normative CIQOL data for adult CI users have the potential to enhance preoperative discussions with CI candidates, improve post-CI activation monitoring, and establish standards for CI centers.

Cochlear implantation performance outcomes in patients over 80 years old

Objective

To examine device datalogging characteristics and postoperative performance in the very elderly CI users.

Methods

Retrospective chart review of postoperative speech recognition outcomes and datalogging characteristics in patients older than 80 years old who underwent cochlear implantation and remain active users with longer than 6 months post-activation follow-up.

Resultss

The mean age at implantation was 84.8 ± 3.8 years old. Pre- and post-operative AzBio sentences in quiet scores were 12.4 ± 16.4% and 53.0 ± 23.5%, respectively (p < .001). Pre- and post-operative consonant-nucleus-consonant (CNC) word scores were 9.4 ± 12.8% and 40.5 ± 20.7%, respectively (p < .001). A nonsignificant negative correlation was noted between the age of implantation and postoperative CNC words and AzBio sentence performance. Significantly decreased performance was noted in the subpopulation with a preoperative diagnosis of dementia. Mean daily use was 10.9 h per day. When available the mean daily usage distribution was 16% speech in noise, 19.1% speech, 51% quiet, 3.8% music, and 9.6% noise. A significant positive correlation was noted between daily use and AzBio sentence and CNC word performance.

Conclusions

Very elderly patients have significant postoperative auditory performance benefits after CI. Mean daily use is comparable to previously published results in the younger population. Age of implantation does not play a significant role in overall performance. Elderly patients who are medically cleared for implantation receive significant postoperative benefits.

Cochlear Implantation in Neurofibromatosis Type 2: Experience From the UK Neurofibromatosis Type 2 Service

OBJECTIVE

To review the outcomes of cochlear implants (CI) in patients with neurofibromatosis type 2 (NF2) in a large cohort, and identify factors associated with poor hearing benefit.

STUDY DESIGN

Fifteen-year retrospective national observational case series.

SETTING

United Kingdom regional NF2 multidisciplinary teams.

PATIENTS

Consecutive patients with NF2 receiving a CI.

INTERVENTIONS

CI for hearing rehabilitation.

MAIN OUTCOME MEASURES

1) Audiometric performance at 9 to 12 months after implantation using City University of New York (CUNY) sentence recognition score, and Bamford- Kowal-Bench (BKB) word recognition score in quiet (BKBq), and in noise (BKBn). 2) CI use at most recent review.

RESULTS

Sixty four consecutive patients, median age 43 years, were included. Nine to 12 months mean audiometric scores were: CUNY 60.9%, BKBq 45.8%, BKBn 41.6%. There was no difference in audiometric outcomes between VS treatment modalities. At most recent review (median 3.6 years from implantation), 84.9% with device in situ/available data were full or part-time users. Between 9 and 12 months and most recent review there was an interval reduction in mean audiometric scores: CUNY -12.9%, BKBq -3.3%, BKBn -4.9%. Larger tumor size and shorter duration of profound hearing loss were the only variables associated with poorer audiometric scores. Tumor growth at the time of surgery was the only variable associated with CI non-use. Individual patient response was highly variable.

CONCLUSIONS

CI can provide significant and sustained auditory benefits to patients with NF2 independent of tumor treatment modality, with the majority of those implanted becoming at least part-time users. Larger datasets are required to reliably assess the role of independent variables.

Effects of Bilateral Cochlear Implantation on Binaural Listening Tasks for Younger and Older Adults

PURPOSE

This study investigated the objective and subjective benefit of a second cochlear implant (CI) on binaural listening tasks of speech understanding in noise and localization in younger and older adults. We aimed to determine if the aging population can utilize binaural cues and obtain comparable benefits from bilateral CI (BIL_CI) when compared to the younger population.

METHODS

Twenty-nine adults with severe to profound bilateral sensorineural hearing loss were included. Participants were evaluated in two conditions, better CI (BE_CI) alone and BIL_CI using AzBio and Bamford-Kowal-Bench (BKB) sentence in noise tests. Localization tasks were completed in the BIL_CI condition using a broadband stimulus, low-frequency stimuli, and high-frequency stimuli. A subjective questionnaire was administered to assess satisfaction with CI.

RESULTS

Older age was significantly associated with poorer performance on AzBio +5 dB signal-to-noise ratio (SNR) and BKB-speech in noise (SIN); however, improvements from BE_CI to BIL_CI were observed across all ages. In the AzBio +5 condition, nearly half of all participants achieved a significant improvement from BE_CI to BIL_CI with the majority of those occurring in patients younger than 65 years of age. Conversely, the majority of participants who achieved a significant improvement in BKB-SIN were adults >65 years of age. Years of BIL_CI experience and time between implants were not associated with performance. For localization, mean absolute error increased with age for low and high narrowband noise, but not for the broadband noise. Response gain was negatively correlated with age for all localization stimuli. Neither BIL_CI listening experience nor time between implants significantly impacted localization ability. Subjectively, participants report reduction in disability with the addition of the second CI. There is no observed relationship between age or speech recognition score and satisfaction with BIL_CI.

CONCLUSION

Overall performance on binaural listening tasks was poorer in older adults than in younger adults. However, older adults were able to achieve significant benefit from the addition of a second CI, and performance on binaural tasks was not correlated with overall device satisfaction. The significance of the improvement was task and stimulus dependent but suggested a critical limit may exist for optimal performance on SIN tasks for CI users. Specifically, older adults require at least a +8 dB SNR to understand 50% of speech postoperatively; therefore, solely utilizing a fixed +5 dB SNR preoperatively to qualify CI candidates is not recommended as this test condition may introduce limitations in demonstrating CI benefit.