Cochlear implant programming: a global survey on the state of the art

Artificial Intelligence in Otology and Neurotology

Clinical applications of artificial intelligence (AI) have grown exponentially with increasing computational power and Big Data. Data rich fields such as Otology and Neurotology are still in the infancy of harnessing the power of AI but are increasingly involved in training and developing ways to incorporate AI into patient care. Current studies involving AI are focused on accessible datasets; health care wearables, tabular data from electronic medical records, electrophysiologic measurements, imaging, and "omics" provide huge amounts of data to utilize. Health care wearables, such as hearing aids and cochlear implants, are a ripe environment for AI implementation.

Experienced Adult Cochlear Implant Users Show Improved Speech Recognition When Target Fitting Parameters Are Applied

OBJECTIVES

The aim of the present study was to investigate whether prediction models built by de Graaff et al. (2020 ) can be used to improve speech recognition in experienced adult postlingual implanted Cochlear CI users. de Graaff et al. (2020 ) found relationships between elevated aided thresholds and a not optimal electrical dynamic range (<50 CL or >60 CL), and poorer speech recognition in quiet and in noise. The primary hypothesis of the present study was that speech recognition improves both in quiet and in noise when the sound processor is refitted to match targets derived from the prediction models from de Graaff et al. (2020 ). A second hypothesis was that subjectively, most of the CI users would find the new setting too loud because of an increase in C levels, and therefore, prefer the old settings.

DESIGN

A within-participant repeated measures design with 18 adult Cochlear CI users was used. T- and C-levels were changed to "optimized settings," as predicted by the model of de Graaff et al. (2020 ). Aided thresholds, speech recognition in quiet, and speech recognition in noise were measured with the old settings and after a 4-week acclimatization period with the optimized settings. Subjective benefit was measured using the Device Oriented Subjective Outcome Scale questionnaire.

RESULTS

The mean electrical dynamic range changed from 41.1 (SD = 6.6) CL to 48.6 (SD = 3.0) CL. No significant change in aided thresholds was measured. Speech recognition improved for 16 out of 18 participants and remained stable for 2 participants. Average speech recognition scores in quiet significantly improved by 4.9% (SD = 3.8%). No significant change for speech recognition in noise was found. A significant improvement in subjective benefit was found for one of the Device Oriented Subjective Outcome subscales (speech cues) between the old and optimized settings. All participants chose to keep the optimized settings at the end of the study.

CONCLUSIONS

We were able to improve speech recognition in quiet by optimizing the electrical dynamic range of experienced adult CI users, according to the prediction models built by de Graaff et al. (2020 ). There was no significant change in aided thresholds nor in speech recognition in noise. The findings of the present study suggest that improved performance for speech recognition in quiet in adult Cochlear CI users can be achieved by setting the dynamic range as close as possible to values between 50 and 60 CL when the volume level is at 10.

Integrated bimodal fitting and binaural streaming technology outcomes for unilateral cochlear implant users

OBJECTIVE

Adults typically receive only one cochlear implant (CI) due to cost constraints, with a contralateral hearing aid recommended when there is aidable hearing. Standard hearing aids differ from a CI in terms of processing strategy and function as a separate entity, requiring the user to integrate the disparate signals. Integrated bimodal technology has recently been introduced to address this challenge. The aim of the study was to investigate the performance of unilateral CI users with and without an integrated bimodal fitting and determine whether binaural streaming technology offers additional benefit.

STUDY SAMPLE

Twenty-six CI users using integrated bimodal technology.

DESIGN

Repeated measures where outcomes and user experience were assessed using a functional test battery more representative of real life listening (speech perception in noise tests, localisation test, tracking test) and the speech, spatial and qualities-of-hearing scale (SSQ).

RESULTS

Bimodal outcomes were significantly better than for CI alone. Speech perception in noise improvements ranged from 1.4 dB to 3.5 dB depending on the location of speech and noise. The localisation and tracking tests, and the SSQ also showed significant improvements. Binaural streaming offered additional improvement (1.2 dB to 6.1 dB on the different speech tests).

CONCLUSIONS

Integrated bimodal and binaural streaming technology improved the performance of unilateral CI users.

The relation between cochlear implant programming levels and speech perception performance in post-lingually deafened adults: a data-driven approach

PURPOSE

Programming a cochlear implant (fitting) is an essential part of a user's post-implantation journey, defining how sound will be translated into electrical stimulation and aiming to provide optimal speech perception outcomes. Currently, there are no established, evidence-based guidelines for fitting cochlear implant users, leading to a high degree of variability in fitting practices, users' parameters, and probably outcomes. In this study a data-driven approach is used to retrospectively investigate the relation between cochlear implant fitting parameters and speech perception outcomes in post-lingually deafened adults.

METHODS

298 data points corresponding to fitting parameters and speech audiometry test results for the same number of adult, post-lingually deafened, experienced CI users were analyzed. Correlation analysis was performed, after which parameters from the top-scoring and bottom-scoring tertiles were compared via the Mann-Whitney-Wilcoxon u test.

RESULTS

Weak correlations between dynamic range and speech audiometry outcomes were identified, having p values lower than (albeit close to) 0.05. A significant (p < 0.05) difference in electrical dynamic range (the difference between the minimum and maximum amount of current which may be delivered by each electrode) was found, with top-scoring subjects having on average a wider dynamic range.

CONCLUSION

The association between dynamic range and speech perception outcomes shown in this retrospective study highlights the need for deeper investigation into evidence-driven fitting. It might be a first step in the direction of evidence-based fitting, minimizing variability in outcomes for cochlear implant users and helping mitigate the issue of unexplained low performance.

Effects of Intraoperative Cochlear Implant Electrode Conditioning on Impedances and Electrically Evoked Compound Action Potentials

OBJECTIVE

The current study investigates whether, during a Cochlear Implant (CI) surgery, conditioning (i.e. applying short bursts of electrical stimulation) within a saline solution can have positive effects on subsequent intra-operative measurements. We hypothesize that, based on previous research, the impedance values will be reduced, and that the reproducibility of Electrically Evoked Compound Action Potentials (ECAPs) is improved as a result of conditioning.

METHODS

We conditioned half of the electrode contacts, within a saline solution, before CI insertion, using 23 MED-EL implants. Impedance was measured for both the conditioned and non-conditioned groups at five time points. Repeated ECAP recordings were measured and compared between the conditioned and non-conditioned groups.

RESULTS

Impedance of the electrode contacts were reduced by 31% after conditioning in saline solution; however, there were no clinically relevant differences after the implantation of the electrode array. The hypothesis that measurement reproducibility would be increased after conditioning could not be confirmed with our data. Within the saline solution, we observed that 44% of the electrode contacts were covered with air bubbles, which most disappeared after implantation. However, these air bubbles limited the effectiveness of the conditioning within the saline solution. Lastly, the effect of conditioning on the reference electrode stimulation was approximately 16% of the total reduction in impedance.

CONCLUSION

Our data does not suggest that intraoperative conditioning is clinically required for cochlear implantation with MED-EL implants. Additionally, an in-vivo ECAP recording can be considered as a method of conditioning the electrode contacts.

SIGNIFICANCE

We confirm that the common clinical practice does not need to be changed.

Development of Custom Sound® Pro software utilising big data and its clinical evaluation

OBJECTIVES

To inform and optimise a cochlear implant (CI) fitting software design through an analysis of big data to define array-specific comfort (C) level profiles, frequently-used MAP parameters, and the minimum number of Neural Response Telemetry thresholds (tNRT) needed to create an accurate profile. To evaluate the software's ease of use and completion time for AutoNRT®s.

DESIGN

MAPs analysis. Clinical study evaluating software use in creating MAPs, addressing sound-quality issues and setting patient goals.

STUDY SAMPLE

MAPs (N = 39,885); CI recipients (N = 47) and clinicians (N = 19).

RESULTS

Distinct C-level profiles were observed for lateral-wall, contour, and slim-modiolar electrode arrays. Default settings were used for most MAP parameters (13/16) except for Pulse Width, Rate, and Maxima. Nine tNRT measurements were required for an accurate C-level profile. Measurement-time of nine tNRTs via the new algorithm was comparable to five tNRTs using the previous algorithm. Nearly all (99%) clinical tasks were completed by clinicians with the first use of the software. Most CI recipients (79.5%) rated goal-setting as valuable.

CONCLUSION

Custom Sound Pro fitting software developed based on big data analysis incorporates a guided fitting workflow and expected fitting ranges. It helps to improve clinical efficiency, is easy to use and supports patient-centred care.

Comparison of Tonotopic and Default Frequency Fitting for Speech Understanding in Noise in New Cochlear Implantees: A Prospective, Randomized, Double-Blind, Cross-Over Study

OBJECTIVES

While cochlear implants (CIs) have provided benefits for speech recognition in quiet for subjects with severe-to-profound hearing loss, speech recognition in noise remains challenging. A body of evidence suggests that reducing frequency-to-place mismatch may positively affect speech perception. Thus, a fitting method based on a tonotopic map may improve speech perception results in quiet and noise. The aim of our study was to assess the impact of a tonotopic map on speech perception in noise and quiet in new CI users.

DESIGN

A prospective, randomized, double-blind, two-period cross-over study in 26 new CI users was performed over a 6-month period. New CI users older than 18 years with bilateral severe-to-profound sensorineural hearing loss or complete hearing loss for less than 5 years were selected in the University Hospital Centre of Rennes in France. An anatomical tonotopic map was created using postoperative flat-panel computed tomography and a reconstruction software based on the Greenwood function. Each participant was randomized to receive a conventional map followed by a tonotopic map or vice versa. Each setting was maintained for 6 weeks, at the end of which participants performed speech perception tasks. The primary outcome measure was speech recognition in noise. Participants were allocated to sequences by block randomization of size two with a ratio 1:1 (CONSORT Guidelines). Participants and those assessing the outcomes were blinded to the intervention.

RESULTS

Thirteen participants were randomized to each sequence. Two of the 26 participants recruited (one in each sequence) had to be excluded due to the COVID-19 pandemic. Twenty-four participants were analyzed. Speech recognition in noise was significantly better with the tonotopic fitting at all signal-to-noise ratio (SNR) levels tested [SNR = +9 dB, p = 0.002, mean effect (ME) = 12.1%, 95% confidence interval (95% CI) = 4.9 to 19.2, standardized effect size (SES) = 0.71; SNR = +6 dB, p < 0.001, ME = 16.3%, 95% CI = 9.8 to 22.7, SES = 1.07; SNR = +3 dB, p < 0.001 ME = 13.8%, 95% CI = 6.9 to 20.6, SES = 0.84; SNR = 0 dB, p = 0.003, ME = 10.8%, 95% CI = 4.1 to 17.6, SES = 0.68]. Neither period nor interaction effects were observed for any signal level. Speech recognition in quiet ( p = 0.66) and tonal audiometry ( p = 0.203) did not significantly differ between the two settings. 92% of the participants kept the tonotopy-based map after the study period. No correlation was found between speech-in-noise perception and age, duration of hearing deprivation, angular insertion depth, or position or width of the frequency filters allocated to the electrodes.

CONCLUSION

For new CI users, tonotopic fitting appears to be more efficient than the default frequency fitting because it allows for better speech recognition in noise without compromising understanding in quiet.

Reliability and validity assessment of a survey: Measuring satisfaction with cochlear implant rehabilitation services for children in Jordan

BACKGROUND

Assessing parental satisfaction with healthcare services is crucial, particularly for parents and their children, who are the primary recipients of these services. In the context of Arabic-speaking parents, there is a notable absence of survey instruments tailored to measure their satisfaction. This study seeks to address this gap by validating a survey designed to evaluate parental satisfaction with rehabilitation services (RSs) provided to Jordanian children who have received cochlear implants (CIs).

METHODS

The study included 92 participants and followed a four-step methodology: 1) a literature review and expert input; 2) cognitive interviews, pilot testing, and test-retest reliability testing; 3) data collection; 4) validity and reliability assessments.

RESULTS

The survey's validity was confirmed. Expert input and cognitive interviews improved content validity, and factor analysis established construct validity by revealing six factors explaining 82.33% of the variance in the survey scale. Convergent and discriminant validity were confirmed (composite reliability >0.7 and average variance extracted value >0.5). Cronbach's α exceeded 0.8 for each factor and reached 0.855 for the total scale. Survey results showed reliance on speech therapy and audiology, varied rehabilitation durations, and progress. Parents expressed overall satisfaction, particularly influenced by technical quality and efficacy/outcome dimensions. Parents' recommendations to enhance satisfaction with RSs included financial support, improved service accessibility, enhanced service delivery, specialized education, and increased public awareness.

CONCLUSION

This study validates an Arabic satisfaction survey, emphasizing the significance of multidisciplinary, extended rehabilitation programs, skilled professionals, and positive outcomes. It emphasizes the necessity for improved access to specialized care and collaboration among healthcare, government, and media to shape parental perceptions of RSs. While the findings indicate overall satisfaction, they also reveal challenges faced by parents, highlighting the need for comprehensive support systems. These insights assist healthcare providers and policymakers in enhancing care quality and meeting the needs of CI children's families, thereby improving the RSs experience in Jordan.

Preliminary Evidence to Support a De-Escalated Cochlear Implant Programming Paradigm for New Adult Recipients: A Systematic Review

Background: No standard schedule for cochlear implant (CI) programming has been developed, and common practices may have CI recipients seen in excess of what is necessary. The objective of this study was to review evidence for a de-escalated, evidence-based schedule for adult CI programming. Methods: Systematic review was undertaken in March 2023 of PubMed, Scopus, and CINAHL databases using the Preferred Reporting Items for Systemic Reviews and Meta-analyses (PRISMA) guidelines. Studies were included if (1) they evaluated an evidence-based programming/follow-up schedule in new adult CI patients or (2) they evaluated programming or outcomes in a longitudinal fashion such that they could inform CI follow-up strategies. Level of evidence was evaluated using the LEGEND evidence assessment tool. Results: Our review identified 940 studies. After screening with a priori inclusion criteria, 18 studies were ultimately included in this review. Of these, 2 demonstrated feasibility of de-escalated approaches to new adult CI programming. The remainder presented longitudinal speech and programming parameter data that demonstrated relative stability of both categories by 3 to 6 months post-activation. Conclusions: Overall, there is a paucity of literature evaluating any form of evidence-based CI programming or follow-up. Most applicable data derive from longitudinal outcomes featured in studies of other CI features, with only a handful of studies directly evaluating CI programming strategies over time. However, stability in outcomes and programming detailed in the available data supports consideration of a de-escalated programming paradigm that could primarily limit programming to the very early post-activation period (before 3 to 6 months) to enhance patient care and reduce operational strains on cochlear implant programs.

A Literature Review on Cochlear Implant Activation: From Weeks to Hours

Objectives: The present literature review discusses the chronological evolution of Cochlear Implant (CI) activation and its definition among the relevant studies in the literature. In addition, the benefits of standardizing the early activation process in implantation centers worldwide are discussed. Methods: A comprehensive literature search was conducted in the major databases such as PubMed, Scopus, and Embase to retrieve all the relevant articles that reported early activation approaches following CI. Results: The evolution of the timing of early activation after CI has been remarkable in the past few years. Some studies reported the feasibility of early activation 1 day after the CI surgery in their users. Conclusions: Within the last decade, some studies have been published to report the feasibility and outcomes of its early activation. However, the process of early activation was not adequately defined, and no apparent guidelines could be found in the literature.

Speech-in-noise performance in objectively determined cochlear implant maps, including the effect of cognitive state

OBJECTIVE

Cochlear Implant (CI) programming based on subjective psychophysical fine-tuning of loudness scaling involves active participation and cognitive skills and thus may not be appropriate for difficult-to-condition populations. The electrically evoked stapedial reflex threshold (eSRT) is an objective measure that is suggested to provide clinical benefit to CI programming. This study aimed to compare speech reception outcomes between subjective and eSRT objectively determined CI maps for adult MED-EL recipients. The effect of cognitive skills on these skills was further assessed.

METHODS

Twenty-seven post lingually hearing-impaired MED-EL CI recipients were recruited, 6 with mild cognitive impairment (MCI- 4 male, 79 years ± 5), 21 with normal cognitive function (5 male, 63 years ± 12). Two MAPs were generated: a subjective MAP and an objective MAP in which eSRTs determined maximum comfortable levels (M-Levels). Participants were randomly divided into two groups. Group A trialled the objective MAP for two weeks before returning for outcome assessment. During the following two weeks, Group A trialled the subjective MAP before returning for outcome assessment. Group B trialled MAPs in reverse. Outcome measures included the Hearing Implant Sound Quality Index (HISQUI), Consonant-Nucleus-Consonant (CNC) word test, and Bamford-Kowal-Bench Speech-in-Noise (BKB-SIN) test.

RESULTS

eSRT based MAPS were obtained in 23 of the participants. A strong relationship was demonstrated between global charge between eSRT-based and psychophysical-based M-Levels (r = 0.89, p < .001). The Montreal Cognitive Assessment for the Hearing Impaired (MoCA-HI) testing identified 6 CI recipients with MCI (MoCA-HI total score ≤23). The MCI group was older (63, 79 years), but were not otherwise different in sex, duration of hearing loss or duration of CI use. For all patients, no significant differences were found for sound quality or speech in quiet scores between eSRT-based and psychophysical-based MAPs. However, psychophysically determined MAPs showed significantly better speech-in-noise reception (6.74 vs 8.20-dB SNR, p = .34). MoCA-HI scores showed a significant, moderate negative correlation with BKB SIN for both MAP approaches (Kendall's Tau B, p = .015 and p = .008), with no effect on the difference between MAP approaches.

CONCLUSION

Results indicate eSRT-based methods provide poorer outcomes than psychophysical-based method. While speech-in-noise reception is correlated with MoCA-HI score, this affected both behaviourally and objectively determined MAPs. The results suggest fair confidence in the eSRT-based method as a guide for setting M-Level for difficult-to-condition CI populations in simple listening conditions.

Early activation after cochlear implantation: a systematic review

PURPOSE

To systematically review the outcomes of early activation following cochlear implantation (CI) based on the findings from different studies in the literature.

METHODS

A comprehensive search strategy was conducted through different databases to identify relevant articles. Our outcomes included impedance levels, rates of complications, hearing and speech perception performance, and patients' satisfaction levels.

RESULTS

The total number of included studies in this systematic review is 19, which recruited 1157 patients, including 857 who underwent early activation following CI. Seventeen studies investigated impedance levels or feasibility rates of early activation approaches. Most of these studies (n = 10) reported that mean impedance levels remarkably decreased within the first day-to-month (first measurement) post-activation. In addition, all 17 studies showed that impedance levels finally normalize and become comparable with intraoperative levels or the conventional activation group. Seventeen studies reported the occurrence of complications in their population. Ten of these studies indicated that none of their patients developed any post-operative complications after early activation. Seven studies reported the development of some minor complications, including pain 9.2% (28/304), infection 4.7% (13/275), swelling 8.2% (25/304), vertigo 15.1% (8/53), skin hyperemia 2.2% (5/228), and others 16.4% (9/55). Hearing and speech perception was assessed in six studies, which showed a remarkable improvement in their patients. Three studies investigated patients' satisfaction and showed high satisfaction levels. Only one report investigated the economic advantages of early activation.

CONCLUSION

Early activation is safe and feasible and does not impact the hearing and speech outcomes of the patients undergoing CI procedures.

Knowledge, Beliefs, and Practices Towards Cochlear Implantations Among Otorhinolaryngologists in India

The outcome of the cochlear implant is dependent highly on the knowledge, belief and practice of cochlear implant in otolaryngologists who are among the important team members. The study explored the knowledge, beliefs, and practices towards cochlear implantations among otorhinolaryngologists in India. An online cross-sectional survey study was carried out using convenient sampling among otorhinolaryngologists in India. Phase-I involved developing and validating of a questionnaire to study the knowledge, beliefs, and practices towards cochlear implants among otorhinolaryngologists in India while phase II involved administration of the questionnaire and analysis. Data collection was conducted using Google Forms. A total of 106 otorhinolaryngologists participated across 24-65 years of age and with experience ranging from 1 to 42 years. The participating otorhinolaryngologists reported having good knowledge about the candidacy for a cochlear implant but having limited knowledge of the recent developments and governmental schemes. The otorhinolaryngologists displayed positive beliefs regarding cochlear implantation. Most recommended a battery of tests to determine the candidacy and gave a lot of importance to rehabilitation (96.2%) and surgery for implantation (83%). The respondents also practiced giving importance to a team approach involving multiple team members. High costs and financial burden emerged to be the major challenges for cochlear implantation in India. The findings of the survey indicate an overall positive belief and practices towards cochlear implantation by otorhinolaryngologists in India. However, there is a need to spread more awareness among them about the recent advances and schemes that would further improve their service delivery.

Evaluation of a clinical method for selective electrode deactivation in cochlear implant programming

Background

Cochlear implants are a neural prosthesis used to restore the perception of hearing in individuals with severe-to-profound hearing loss by stimulating the auditory nerve with electrical current through a surgically implanted electrode array. The integrity of the interface between the implanted electrode array and the auditory nerve contributes to the variability in outcomes experienced by cochlear implant users. Strategies to identify and eliminate poorly encoding electrodes have been found to be effective in improving outcomes with the device, but application is limited in a clinical setting.

Objective

The purpose of this study was to evaluate a clinical method used to identify and selectively deactivate cochlear implants (CI) electrodes related to poor electrode-neural interface.

Methods

Thirteen adult CI users participated in a pitch ranking task to identify indiscriminate electrode pairs. Electrodes associated with indiscriminate pairs were selectively deactivated, creating an individualized experimental program. Speech perception was evaluated in the baseline condition and with the experimental program before and after an acclimation period. Participant preference responses were recorded at each visit.

Results

Statistically significant improvements using the experimental program were found in at least one measure of speech perception at the individual level in four out of 13 participants when tested before acclimation. Following an acclimation period, ten out of 13 participants demonstrated statistically significant improvements in at least one measure of speech perception. Statistically significant improvements were found with the experimental program at the group level for both monosyllabic words (p = 0.006) and sentences in noise (p = 0.020). Additionally, ten participants preferred the experimental program prior to the acclimation period and eleven preferred the experimental program following the acclimation period.

Conclusion

Results from this study suggest that electrode deactivation may yield improvement in speech perception following an acclimation period. A majority of CI users in our study reported a preference for the experimental program. This method proved to be a suitable clinical strategy for identifying and deactivating poorly encoding electrodes in adult CI users.

Models of service delivery in adult cochlear implantation and evaluation of outcomes: A scoping review of delivery arrangements

BACKGROUND

This study aimed to describe available evidence of cochlear implantation delivery arrangements in adults and the outcomes by which these service models are measured.

METHODS

Scoping review of English language, primary studies conducted on adults (≥18 years) with ten or more subjects, published between January 2000 and June 2022, which assessed the effects of delivery arrangements of cochlear implantation were included. MEDLINE, EMBASE, CINAHL Plus, AMED, PsycINFO, LILACS, KoreaMed, IndMed, Cochrane CRCT, ISRCTN registry, WHO ICTRP and Web of Science were systematically searched. Included studies had to have a method section explicitly measure at least one of the Cochrane Effective Practice and Organization of Care (EPOC) outcome category. Criteria for systematic reviews and delivery arrangement category based on EPOC taxonomy was included in data extraction. Data was narratively synthesized based on EPOC categories.

RESULTS

A total of 8135 abstracts were screened after exclusion of duplicates, of these 357 studies fulfilled the inclusion criteria. Around 40% of the studies investigated how care is delivered, focusing on quality and safety systems. New care pathways to coordinate care and the use of information and communication technology were emerging areas. There was little evidence on continuity, coordination and integration of care, how the workforce is managed, where care is provided and changes in the healthcare environment. The main outcome measure for various delivery arrangements were the health status and performance in a test.

CONCLUSION

A substantial body of evidence exists about safety and efficacy of cochlear implantation in adults, predominantly focused on surgical aspects and this area is rapidly growing. There is a lack of evidence on aspects of care delivery that may have more impact on patients' experience such as continuity, coordination and integration of care and should be a focus of future research. This would lead to a better understanding of how patient's view CI experience, associated costs and the value of different care models.

Prospective Comparison Between Manual and Computer-Assisted (FOX) Cochlear Implant Fitting in Newly Implanted Patients

OBJECTIVE

A prospective, longitudinal, randomized controlled trial with an original crossover design for 1 year was conducted to compare manual fitting to artificial intelligence-based fitting in newly implanted patients.

DESIGN

Twenty-four patients who received their first cochlear implant (CI) were randomly assigned to the manual or Fitting to Outcome eXpert (FOX) arm; they followed the corresponding fitting procedures for 1 year. After 1 year, each patient was switched to another arm. The number of fittings, auditory outcomes (pure-tone thresholds, loudness scaling curves, spectral discrimination scores, bisyllabic word recognition in quiet and noise, and speech tracking), fitting session questionnaire, and CI parameters (T level, C level, Threshold Sound Pressure Level (T-SPL), Comfortable Sound Pressure Level (C-SPL), and loudness growth value) were compared between the two groups. Differences between the two groups were analyzed using the Mann-Whitney test, and Holm corrections were applied for multiple statistical tests. At the end of the crossover session, patients were offered the choice to continue with their old or new map.

RESULTS

As early as 3 mo postactivation, the FOX group showed less variability and significantly better speech intelligibility in quiet conditions at 40 and 55 dB SPL and noise ( p < 0.05) with median phoneme scores of 50%, 70%, and 50% at 55, 70, and 85 dB SPL compared with 45%, 50%, and 40%, respectively. This group showed better results at 12 mo postactivation ( p < 0.05). In the manual group, 100% of the patients decided to keep the new FOX map, and 82% performed better with the FOX map. In the FOX group, 63% of the patients decided to keep the manual map, although the measurable outcome had not improved. In this group, participants reported to prefer the manual map because it felt more comfortable, even if the FOX map gave better measured outcome.

CONCLUSION

Although the study size remains relatively small, the AI-FOX approach was equivalent to or even outperformed the manual approach in hearing performance, comfort, and resources. Furthermore, FOX is a tool capable of continuous improvement by comparing its predictions with observed results and is continuously learning from clinicians' practice, which is why this technology promises major advances in the future.

The Relationship Between Interaural Insertion-Depth Differences, Scalar Location, and Interaural Time-Difference Processing in Adult Bilateral Cochlear-Implant Listeners

Sensitivity to interaural time differences (ITDs) in acoustic hearing involves comparison of interaurally frequency-matched inputs. Bilateral cochlear-implant arrays are, however, only approximately aligned in angular insertion depth and scalar location across the cochleae. Interaural place-of-stimulation mismatch therefore has the potential to impact binaural perception. ITD left-right discrimination thresholds were examined in 23 postlingually-deafened adult bilateral cochlear-implant listeners, using low-rate constant-amplitude pulse trains presented via direct stimulation to single electrodes in each ear. Angular insertion depth and scalar location measured from computed-tomography (CT) scans were used to quantify interaural mismatch, and their association with binaural performance was assessed. Number-matched electrodes displayed a median interaural insertion-depth mismatch of 18° and generally yielded best or near-best ITD discrimination thresholds. Two listeners whose discrimination thresholds did not show this pattern were confirmed via CT to have atypical array placement. Listeners with more number-matched electrode pairs located in the scala tympani displayed better thresholds than listeners with fewer such pairs. ITD tuning curves as a function of interaural electrode separation were broad; bandwidths at twice the threshold minimum averaged 10.5 electrodes (equivalent to 5.9 mm for a Cochlear-brand pre-curved array). Larger angular insertion-depth differences were associated with wider bandwidths. Wide ITD tuning curve bandwidths appear to be a product of both monopolar stimulation and angular insertion-depth mismatch. Cases of good ITD sensitivity with very wide bandwidths suggest that precise matching of insertion depth is not critical for discrimination thresholds. Further prioritizing scala tympani location at implantation should, however, benefit ITD sensitivity.

Cortical auditory evoked potential in cochlear implant users: An objective method to improve speech perception

OBJECTIVE

To investigate if cortical auditory evoked potential (CAEP) measures can be used to verify the cochlear implant (CI) map and consequently improve CI outcomes in adults with bilateral hearing loss.

DESIGN

CAEPs were measured in CI recipients using the speech tokens /m/, /g/, /t/ and /s/. If CAEP responses were present for all speech tokens, the participant's map was considered "satisfactory". If CAEP responses were absent, the CI map was considered "unsatisfactory" and therefore adjusted and CAEP measures repeated. This was repeated until auditory potentials were seen in response to all four speech tokens. Speech testing was conducted pre-CI, as well as before and after CAEP-guided map adjustments.

RESULTS

108 adult unilateral CI users participated, whose sound processors were previously programmed using subjective methods. 42 CI users elicited a CAEP response to all four speech tokens and therefore no further mapping adjustments were made. 66 subjected lacked a CAEP response to at least one speech token and had their CI map adjusted accordingly. Of those, 31 showed a CAEP response to all four speech tokens, and the average speech score significantly improved after CI map adjustments based on CAEP responses.

CONCLUSION

CAEP's are an objective tool that can be used to guide and verify CI mapping in adults CI users. Significant improvement in speech scores was observed in participants who had their CI map adjusted based on CAEP responses.

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

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

Spectral and binaural loudness summation of equally loud narrowband signals in single-sided-deafness and bilateral cochlear implant users

Recent studies on loudness perception of binaural broadband signals in hearing impaired listeners found large individual differences, suggesting the use of such signals in hearing aid fitting. Likewise, clinical cochlear implant (CI) fitting with narrowband/single-electrode signals might cause suboptimal loudness perception in bilateral and bimodal CI listeners. Here spectral and binaural loudness summation in normal hearing (NH) listeners, bilateral CI (biCI) users, and unilateral CI (uCI) users with normal hearing in the unaided ear was investigated to assess the relevance of binaural/bilateral fitting in CI users. To compare the three groups, categorical loudness scaling was performed for an equal categorical loudness noise (ECLN) consisting of the sum of six spectrally separated third-octave noises at equal loudness. The acoustical ECLN procedure was adapted to an equivalent procedure in the electrical domain using direct stimulation. To ensure the same broadband loudness in binaural measurements with simultaneous electrical and acoustical stimulation, a modified binaural ECLN was introduced and cross validated with self-adjusted loudness in a loudness balancing experiment. Results showed a higher (spectral) loudness summation of the six equally loud narrowband signals in the ECLN in CI compared to NH. Binaural loudness summation was found for all three listener groups (NH, uCI, and biCI). No increased binaural loudness summation could be found for the current uCI and biCI listeners compared to the NH group. In uCI loudness balancing between narrowband signals and single electrodes did not automatically result in a balanced loudness perception across ears, emphasizing the importance of binaural/bilateral fitting.

Accessing the stapedius muscle via novel surgical retrofacial approach during cochlear implantation surgery: Intraoperative results on feasibility and safety

Human stapedius muscle (SM) can be directly and safely accessed via retrofacial approach, opening new approaches to directly measure the electrically evoked stapedius reflex threshold (eSRT). The measurement of the SM activity via direct surgical access represents a potential tool for objective eSRT fitting of cochlear implants (CI), increasing the benefit experienced by the CI users and leading to new perspectives in the development of smart implantable neurostimulators. 3D middle-ear reconstructions created after manual segmentation and related SM accessibility metrics were evaluated before the CI surgery for 16 candidates with assessed stapedius reflex. Retrofacial approach to access the SM was performed after facial recess exposure. In cases of poor exposition of SM, the access was performed anteriorly to the FN via drilling of the pyramidal eminence (PE). The total access rate of the SM via both the retrofacial and anterior approach of the FN was 100%. In 81.2% of cases (13/16), the retrofacial approach allowed to access the SM on previously categorized well exposed (8/8), partially exposed (4/5), and wholly concealed (1/3) SM with respect to FN. Following intraoperative evaluation in the remaining 18.8% (3/16), the SM was accessed anteriorly via drilling of the PE. Exposure of SM with respect to the FN and the sigmoid sinus’s prominence was a predictor for the suitable surgical approach. The retrofacial approach offers feasible and reproducible access to the SM belly, opening direct access to electromyographic sensing of the eSRT. Surgical planner tools can quantitatively assist pre-surgical assessment.

Cochlear implant mapping strategy to solve difficulty in speech recognition

BACKGROUND

Cochlear implants (CIs) are viable treatment options in patients with severe to profound hearing loss. Speech recognition difficulties were reported in some CI recipients even with a good-aided hearing threshold. The aim of this study was to report a mapping strategy based on different target-aided hearing thresholds to achieve optimal speech recognition and maximize functional outcomes. The safety and efficacy of the mapping strategy were also inspected in the article.

METHODS

This prospective repeated measures study enrolled 20 adult CI recipients with postlingual deafness using the MED-EL CI system. Word and sentence discrimination assessment and administration of a questionnaire pertaining to comfort level were conducted at the end of each session. The electrophysiological features of the CI mapping were recorded.

RESULTS

The correlation between audiometry results and word and sentence recognition was not high. CIs performed best at an audiometry threshold between 25 and 35 dB.

CONCLUSION

CI performance with the best perception relies on a balance between minimizing the hearing threshold and maximizing the dynamic range while maintaining an appropriate comfort level, which was achieved when the target hearing threshold was set at 25-35 dB in this study.

Effect of modified programming parameters on sound field thresholds, speech perception and CAEP among children using CP802 processor

Optimizing and validating programming parameters of Thresholds(T) and most comfortable levels(C) is very important in young children using a cochlear implant who may not be able provide behavioral responses. The present study attempts to describe the changes in T/C level with behavioral and Cortical Auditory Evoked Potentials (CAEP) responses. Twenty participants using CI24RE (ST) implant with CP802 speech processor participated in the study. Three experimentally 'sham' programs were created by a) decreasing T levels, b) raising T levels or c) decreasing C levels in the 'everyday' program. Sound field thresholds and speech perception at 50dBHL were measured for all experimental and everyday programs. Acoustically evoked CAEP measures, namely thresholds for three different stimuli of/ba/,/da/and/ga/, along with amplitude and latency at 80dBnHL were recorded for all programs. The results indicated that modification of T levels did not have significant effect on CAEP threshold, latency, amplitude as also on behavioral measures of sound field thresholds and speech perception. However, reduction of C levels resulted in significantly poor sound field thresholds, speech perception as well as CAEP thresholds. Furthermore, it was found that there was a significant correlation between behavioral measures of sound field threshold and speech perception with CAEP measures. Thus, from the present study it may be concluded that behavioral and CAEP responses can be used as indicator to reflect changes in C levels resulting changes in behavioral measures in users of CP802 speech processors.

Guidelines for Best Practice in the Audiological Management of Adults Using Bimodal Hearing Configurations

Clinics are treating a growing number of patients with greater amounts of residual hearing. These patients often benefit from a bimodal hearing configuration in which acoustic input from a hearing aid on 1 ear is combined with electrical stimulation from a cochlear implant on the other ear. The current guidelines aim to review the literature and provide best practice recommendations for the evaluation and treatment of individuals with bilateral sensorineural hearing loss who may benefit from bimodal hearing configurations. Specifically, the guidelines review: benefits of bimodal listening, preoperative and postoperative cochlear implant evaluation and programming, bimodal hearing aid fitting, contralateral routing of signal considerations, bimodal treatment for tinnitus, and aural rehabilitation recommendations.

Evaluation of Remote Check: A Clinical Tool for Asynchronous Monitoring and Triage of Cochlear Implant Recipients

BACKGROUND

A new Remote Check App permits remote self-testing of hearing function for Nucleus cochlear implant (CI) recipients and enables asynchronous review by their clinician to support patient-management decisions.

OBJECTIVES

To evaluate the Remote Check App for: (1) ease of use; (2) overall acceptance of the test battery by CI recipient or their carer in the home setting; (3) test-retest reliability of audiological threshold and speech recognition measures via wireless streaming; and (4) to compare outcomes from patient-driven measures with conventional clinician-driven measurements of aided-hearing function.

DESIGN

Single-site, prospective, repeated-measures cohort study with 32 experienced CI users (28 adults and 4 children).

METHODS

Participants completed self-testing using the Remote Check app at home and in the clinic. Measures include audiological, objective and subjective tests. Self-administered speech recognition in noise, via the digit triplets test (DTT) and aided thresholds, via the aided threshold test (ATT) were reassessed in free-field and by clinicians following conventional clinical protocols. Results of ATT and DTT were compared across test conditions. Completion time and perceived ease of self-driven assessments were documented. Insights from subsequent real-world experience with Remote Check are summarized and compared to the study findings.

RESULTS

Remote Check was rated as easy to use by the majority (87%) of subjects. Mean group test-retest score differences for self-administered testing within the clinic versus at-home environments were nonsignificant (p > 0.05): 1.4 dB (SD = 1.97) for ATT and 1.6 dB (SD = 1.54) for DTT. Mean group test-retest score difference for patient-driven DTT in streamed versus the free-field condition was 1.8 dB (SD = 2.02). Self-administered, streamed, ATT via Remote Check, resulted in significantly lower thresholds compared to clinician-driven warble-tone thresholds in the free-field by 6.7 dB (SD = 6.8) (p < 0.001). ATT thresholds via Remote Check were not significantly different from predicted thresholds based on the Threshold Sound Pressure Level of the sound processor.

CONCLUSION

Remote Check is the first CI telehealth assessment tool that uses wireless streaming to enable comprehensive, easy and reliable self-testing of hearing function by the CI recipient or their carer, in the comfort of their home. Asynchronous access to test results can assist clinicians in monitoring and triaging individuals for appropriate patient-management based on their needs. Use of remote monitoring may also help to reduce the burden of unnecessary clinic visits on clinic resources, patient travel time and associated costs. Remote Check is an important step toward addressing the current growing need for asynchronous audiological telepractice to support long-term care of CI recipients.

Maximum acceptable level for the determination of ECAP and ESRT in a paediatric population

OBJECTIVES

Two of the most used objective measures are electrically evoked action potentials (ECAPs) and electrically evoked stapedius reflex thresholds (ESRTs). Although stimuli used for these measures differ considerably, both measures are influenced by subjective loudness percept. We focus on the subjective maximum acceptable loudness (MAL) to investigate if loudness sensitivity varied along the electrode array during ECAP recordings. In addition, we explored how the MAL reached during an ECAP recording related to the postoperative ESRT.

METHODS

Uni- and bilaterally implanted young CI users (n = 15, average age = 9 y, age range 3-18 y) underwent ECAP and ESR recordings using the clinical software MAESTRO (MED-EL, Innsbruck, Austria) and a commercially available immittance instrument (PATH MEDICAL GmbH, Germering, Germany).

RESULTS

Loudness tolerance during ECAP recordings was lowest at the two apical-most electrode contacts (number 1 and 2). There was a moderate correlation between the MAL achieved during ECAP recordings and ESR maximum stimulation amplitudes. (r: 0.44344).

CONCLUSIONS

ECAP recordings should commence at basal or medial contacts to increase the users' comfort and loudness tolerance, especially in young CI users. A higher maximum stimulation appears to increase the chance of the automatic determination of ECAP thresholds for all electrode contacts.

ARTFit—A Quick and Reliable Tool for Performing Initial Fittings in Users of MED-EL Cochlear Implants

This study assessed the safety and performance of ARTFit, a new tool embedded in MAESTRO, the cochlear implant (CI) system software by MED-EL GmbH (Innsbruck, Austria). ARTFit automatically measures thresholds of the electrically evoked compound action potential (ECAP) to produce initial ‘maps’ (ECAPMAPs), i.e., configuration settings of the audio processor that the audiologist switches to live mode and adjusts for comfortable loudness (LiveECAPMAPs). Twenty-three adult and ten pediatric users of MED-EL CIs participated. The LiveECAPMAPs were compared to behavioral maps (LiveBurstMAPs) and to the participants’ everyday clinical maps (ClinMAPs). Four evaluation measures were considered: average deviations of the maximum comfortable loudness (MCL) levels of the LiveECAPMAPs and the LiveBurstMAPs from the MCLs of the ClinMAPs; correlations between the MCLs of the LiveECAPMAPs (MCL_ecap) and the LiveBurstMAPs (MCL_burst) with the MCLs of the ClinMAPs (MCL_clin); fitting durations; and speech reception thresholds (SRTs). All evaluation measures were analyzed separately in the adult and pediatric subgroups. For all evaluation measures, the deviations of the LiveECAPMAPs from the ClinMAPs were not larger than those of the LiveBurstMAPs from the ClinMAPs. The Pearson correlation between the MCL_ecap and the MCL_clin across all channels was r² = 0.732 (p < 0.001) in the adult and r² = 0.616 (p < 0.001) in the pediatric subgroups. The mean fitting duration in minutes for the LiveECAPMAPs was significantly shorter than for that of the LiveBurstMAPs in both subgroups: adults took 5.70 (range 1.90–11.98) vs. 9.27 (6.83–14.72) min; children took 3.03 (1.97–4.22) vs. 7.35 (3.95–12.77). SRTs measured with the LiveECAPMAPs were non-inferior to those measured with the ClinMAPs and not statistically different to the SRTs measured with the LiveBurstMAPs. ARTFit is a safe, quick, and reliable tool for audiologists to produce ECAP-based initial fitting maps in adults and young children who are not able to provide subjective feedback.

Frequency Fitting Optimization Using Evolutionary Algorithm in Cochlear Implant Users with Bimodal Binaural Hearing

Optimizing hearing in patients with a unilateral cochlear implant (CI) and contralateral acoustic hearing is a challenge. Evolutionary algorithms (EA) can explore a large set of potential solutions in a stochastic manner to approach the optimum of a minimization problem. The objective of this study was to develop and evaluate an EA-based protocol to modify the default frequency settings of a MAP (fMAP) of the CI in patients with bimodal hearing. Methods: This monocentric prospective study included 27 adult CI users (with post-lingual deafness and contralateral functional hearing). A fitting program based on EA was developed to approach the best fMAP. Generated fMAPs were tested by speech recognition (word recognition score, WRS) in noise and free-field-like conditions. By combining these first fMAPs and adding some random changes, a total of 13 fMAPs over 3 generations were produced. Participants were evaluated before and 45 to 60 days after the fitting by WRS in noise and questionnaires on global sound quality and music perception in bimodal binaural conditions. Results: WRS in noise improved with the EA-based fitting in comparison to the default fMAP (41.67 ± 9.70% versus 64.63 ± 16.34%, respectively, p = 0.0001, signed-rank test). The global sound quality and music perception were also improved, as judged by ratings on questionnaires and scales. Finally, most patients chose to keep the new fitting definitively. Conclusions: By modifying the default fMAPs, the EA improved the speech discrimination in noise and the sound quality in bimodal binaural conditions.

Evaluation of the Electrically-Evoked Stapedial Reflex Threshold in Pediatric Cochlear Implant Users with High-Frequency Probe Tones

Introduction Measurement of the electrically-evoked stapedial reflex threshold (ESRT) is an objective tool used to set the comfort levels in pediatric cochlear implant (PCI) users. The levels of ESRT have a strong correlation with comfort levels. However, the clinical utility of ESRT is limited because the ESRT response is not observed in all cochlear implant users.

Objective To assess the effects of probe-tone frequency on ESRT and its relationship with the behavioral comfort levels in PCI users.

Methods A total of 14 PCI users aged between 5 and 8 years participated in the study. The ESRT levels were measured using high-frequency probe tones (678 Hz and 1,000 Hz), and the default 226 Hz probe tone. The ESRT was measured with single-electrode stimulation across the three electrode locations (basal [E01]; middle [E11]; and apical [E22]). The ESRT levels measured with different probe tone frequencies were compared with the behavioral comfort levels.

Results The mean ESRT levels using 1,000Hz and 678 Hz were lower than those measured using 226 Hz, but there was no main effect of probe-tone frequency (p > 0.05). A significantly high incidence of successful ESRT measurements occurred with higher-frequency probe tone (p < 0.039). Additionally, ESRT using higher probe tones significantly correlated with comfort levels.

Conclusion The ESRT with higher probe tones was correlated with behavioral comfort levels and increased the success rate of the measurements. Higher-frequency probe tones may be useful whenever ESRT with 226 Hz is not measurable.

The optimal probe tone frequency for eSRT measurements at individual electrodes in children with cochlear implants

BACKGROUND

Higher probe tone frequencies have been shown to increase the elicitation rates in electrically evoked stapedius reflex threshold (eSRT) measurements.

OBJECTIVES

To determine the optimal probe tone frequency for contralateral eSRT measurements at individual electrodes in children with unilateral cochlear implants and to assess the relationship between eSRTs for this frequency and most comfortable levels (M-levels).

MATERIALS AND METHODS

Contralateral eSRT measurements with three probe tone frequencies (226, 678, and 1000 Hz) at individual electrodes were performed on 26 paediatric Advanced Bionics cochlear implant recipients.

RESULTS

The elicitation rates of eSRTs for 226, 678, and 1000 Hz probe tones were 73.08% (57/78), 88.46% (69/78), and 88.46% (69/78), respectively. The average eSRT for the 1000 Hz probe tone was significantly lower than those for 226 and 678 Hz probe tones (p<.001 and p=.009, respectively). ESRTs for the 1000 Hz probe tone and M-levels were significantly correlated at all tested electrodes (all p<.001).

CONCLUSIONS AND SIGNIFICANCE

The optimal probe tone frequency for contralateral eSRT measurement at individual electrodes in children with unilateral cochlear implants is 1000 Hz. ESRTs for the 1000 Hz probe tone are significantly correlated with M-levels and can be used to guide the M-levels setting in these children.

Influence of Postponed Follow-Up after Cochlear Implant Activation during the COVID-19 Pandemic on Aided Sound Field Detection and Speech Recognition

INTRODUCTION

The objective of this study was to assess the influence of postponing the first post-activation follow-up due to the COVID-19 pandemic on the aided sound field detection thresholds and speech recognition of cochlear implant (CI) users.

METHODS

A retrospective review was performed at a tertiary referral center. Two groups of adult CI recipients were evaluated: (1) patients whose first post-activation follow-up was postponed due to COVID-19 closures (postponed group; n = 10) and (2) a control group that attended recommended post-activation follow-ups prior to the COVID-19 pandemic (control group; n = 18). For both groups, electric thresholds were estimated at initial activation based on comfort levels and were measured behaviorally at subsequent post-activation follow-ups. For the control group, behavioral thresholds were measured at the 1-month follow-up. For the postponed group, behavioral thresholds were not measured until 3 months post-activation since the 1-month follow-up was postponed. The aided pure-tone average (PTA) and word recognition results were compared between groups at the 3-month follow-up and at an interim visit 2-9 weeks later.

RESULTS

At the 3-month follow-up, the postponed group had significantly poorer word recognition (23 vs. 42%, p = 0.027) and aided PTA (42 vs. 37 dB HL, p = 0.041) than the control group. No significant differences were observed between 3-month data from the control group and interim data from the postponed group.

CONCLUSIONS

The postponed follow-up after CI activation was associated with poorer outcomes, both in terms of speech recognition and aided audibility. However, these detrimental effects were reversed following provision of an individualized map, with behaviorally measured electric threshold and comfort levels. While adult CI recipients demonstrate an improvement in speech recognition with estimated electric thresholds, the present results suggest that behavioral mapping within the initial weeks of device use may support optimal outcomes.

Comparative Analysis of Cortical Auditory Evoked Potential in Cochlear Implant Users

OBJECTIVES

The primary goal of the study was to investigate electrical cortical auditory evoked potentials (eCAEPs) at maximum comfortable level (MCL) and 50% MCL on three cochlear implant (CI) electrodes and compare them with the acoustic CAEP (aCAEPs), in terms of the amplitude and latency of the P1-N1-P2 complex. This was achieved by comparing the eCAEP obtained with the method described and stimulating single electrodes, via the fitting software spanning the cochlear array and the aCAEP obtained using the HEARLab system at four speech tokens.

DESIGN

Twenty MED-EL (MED-EL Medical Electronics, Innsbruck, Austria) CI adult users were tested. CAEP recording with HEARLab System was performed with speech tokens /m/, /g/, /t/, and /s/ in free field, presented at 55 dB SPL. eCAEPs were recorded with an Evoked Potential device triggered from the MAX Programming Interface (MED-EL Medical Devices) with 70 msec electrical burst at 0.9 Hz at the apical (1), middle (6), and basal (10 or 11) CI electrode at their MCL and 50% MCL.

RESULTS

CAEP responses were recorded in 100% of the test subjects for the speech token /t/, 95% for the speech tokens /g/ and /s/, and 90% for the speech token /m/. For eCAEP recordings, in all subjects, it was possible to identify N1 and P2 peaks when stimulating the apical and middle electrodes. This incidence of detection decreased to an 85% chance of stimulation at 50% MCL on the same electrodes. A P1 peak was less evident for all electrodes. There was an overall increase in latency for stimulation at 50% MCL compared with MCL. There was a significant difference in the amplitude of adjacent peaks (P1-N1 and N1-P2) for 50% MCL compared with MCL. The mean of the maximum cross-correlation values were in the range of 0.63 to 0.68 for the four speech tokens. The distribution of the calculated time shift, where the maximum of the cross-correlation was found, was distributed between the speech tokens. The speech token /g/ had the highest number of valid cross-correlations, while the speech token /s/ had the lowest number.

CONCLUSIONS

This study successfully compared aCAEP and eCAEP in CI users. Both acoustic and electrical P1-N1-P2 recordings obtained were clear and reliable, with good correlation. Latency increased with decreasing stimulation level, while amplitude decreased. eCAEP is potentially a better option to verify speech detection at the cortical level because it (1) uses direct stimulation and therefore creates less interference and delay of the sound processor and (2) creates more flexibility with the recording setup and stimulation setting. As such, eCAEP is an alternative method for CI optimization.

Optimized SNR-based ECAP threshold determination is comparable to the judgement of human evaluators

In cochlear implant (CI) users, measurements of electrically evoked compound action potentials (ECAPs) prove the functionality of the neuron-electrode interface. Objective measures, e.g., the ECAP threshold, may serve as a basis for the clinical adjustment of the device for the optimal benefit of the CI user. As for many neural responses, the threshold determination often is based on the subjective assessment of the clinical specialist, whose decision-making process could be aided by autonomous computational algorithms. To that end, we extended the signal-to-noise ratio (SNR) approach for ECAP threshold determination to be applicable for FineGrain (FG) ECAP responses. The new approach takes advantage of two features: the FG stimulation paradigm with its enhanced resolution of recordings, and SNR-based ECAP threshold determination, which allows defining thresholds independently of morphology and with comparably low computational power. Pearson's correlation coefficient r between the ECAP threshold determined by five experienced evaluators and the threshold determined with the FG-SNR algorithm was in the range of r = 0.78-0.93. Between evaluators, r was in a comparable range of 0.84-0.93. A subset of the parameters of the algorithm was varied to identify the parameters with the highest potential to improve the FG-SNR formalism in the future. The two steps with the strongest influence on the agreement between the threshold estimate of the evaluators and the algorithm were the removal of undesired frequency components (denoising of the response traces) and the exact determination of the two time windows (signal and noise and noise only)."The parameters were linked to the properties of an ECAP response, indicating how to adjust the algorithm for the automatic detection of other neurophysiological responses.

Bimodal Fitting and Bilateral Cochlear Implants in Children With Significant Residual Hearing: The Impact of Asymmetry in Spatial Release of Masking on Localization

Purpose This study aimed to gain more insight into the primary auditory abilities of children with significant residual hearing in order to improve decision making when choosing between bimodal fitting or sequential bilateral cochlear implantation. Method Sound localization abilities, spatial release of masking, and fundamental frequency perception were tested. Nine children with bimodal fitting and seven children with sequential bilateral cochlear implants were included in the study. As a reference, 15 children with normal hearing and two children with simultaneous bilateral cochlear implants were included. Results On all outcome measures, the implanted children performed worse than the normal hearing children. For high-frequency localization, children with sequential bilateral cochlear implants performed significantly better than children with bimodal fitting. Compared to children with normal hearing, the left-right asymmetry in spatial release of masking was significant. When the implant was hindered by noise, bimodally fitted children obtained significantly lower spatial release of masking compared to when the hearing aid was hindered by noise. Overall, the larger the left-right asymmetry in spatial release of masking, the poorer the localization skills. No significant differences were found in fundamental frequency perception between the implant groups. Conclusions The data hint to an advantage of bilateral implantation over bimodal fitting. The extent of asymmetry in spatial release of masking is a promising tool for decision making when choosing whether to continue with the hearing aid or to provide a second cochlear implant in children with significant residual hearing.

Effectiveness of Computer-Based Auditory Training for Adult Cochlear Implant Users: A Randomized Crossover Study

The aim of this study was to assess whether a computer-based speech-in-noise auditory training (AT) program would lead to short- and long-term changes in trained and untrained measures of listening, cognition, and quality of life. A secondary aim was to assess whether directly training the underlying cognitive abilities required for speech perception in noise, using a computer-based visual training (VT) program without the auditory component, would elicit comparable outcomes as the AT program. A randomized crossover study with repeated measures was conducted with 26 adult cochlear implant users. Participants completed either 6 weeks of speech perception in noise training followed by 6 weeks of masked text recognition training, or vice versa. Outcome measures were administered twice before each training program, as well as twice after the completion of each program. The test battery was designed to evaluate whether training led to improvements in listening abilities, cognitive abilities, or quality of life. Mixed-effects models were conducted to analyze whether changes occurred on the trained tasks and on untrained outcome measures after training. Statistically significant improvements were shown for verbal recognition performance during both training programs, in particular for consonants in words, and during the first 2 weeks of training. This on-task learning, however, did not lead to clear improvements in outcomes measured beyond the training programs. This suggests that experienced cochlear implant users may not show transfer of on-task learning to untrained tasks after computer-based auditory and visual training programs such as the ones used in this study.

Decoding Billing Practices in Cochlear Implant Programs

OBJECTIVES

The purpose of this study was to examine current cochlear implant (CI) billing practices across CI audiologists in the United States, to determine if CI audiologists are following the National Correct Coding Initiative (NCCI) edits, and to assess the CI audiologist's exposure to billing education.

DESIGN

A 48-question survey was electronically distributed to and completed by audiologists who bill for CI services. Demographic data including work setting, population served, years of experience, number of CI patients managed per week, and exposure to billing education were collected. Data were analyzed to identify codes and modifiers used to bill for commonly performed CI procedures such as unilateral and bilateral CI programming, preoperative and postoperative testing, and objective measures.

RESULTS

Data were obtained from 96 audiologists. The majority (86.3%, n = 82) of respondents agreed or strongly agreed they understand billing and coding practices for cochlear implants and 94.7% (n = 89) rated themselves as somewhat to highly efficient when performing these practices. Only 16.8% (n = 16) of respondents reported receiving formal training for practice management, and half of the respondents (51.1%, n = 48) reported unfamiliarity with national billing guidelines. Those who received formal training reported higher billing efficiency. Wide variability was seen for various billing scenarios. Billing questions were presented, and answers were coded as correct or incorrect based on the NCCI edits. Respondents who reported higher agreement with understanding billing and who received formal training scored better on common billing questions related to the NCCI edits.

CONCLUSIONS

Most CI audiologists rated themselves as efficient in billing; however, wide variance in billing practices was observed. Incorporating practice management and current billing education into daily practice and into audiology training programs is essential to clinic efficiency, practice management, and CI program viability. CI audiologists should be knowledgeable about appropriate billing practices to ensure long-term sustainability of programs.

Remote check test battery for cochlear implant recipients: proof of concept study

OBJECTIVES

(1) To investigate the remote check test battery, designed for self-administration by cochlear implant (CI) recipients, parents/caregivers, to determine if the results give adequate information for clinicians to decide the necessity of an appointment and to capture suggestions for improvement. (2) To gauge acceptance of remote monitoring by CI-recipients and their parents/caregivers.

DESIGN

Prospective, multicentre, un-blinded, non-randomized, single-subject, repeated-measures evaluation. The test battery includes an implant-site photograph, impedance measurements, datalogs, questionnaires, speech perception and aided threshold tests. Clinicians reviewed test battery results, followed by a clinical appointment with each CI-recipient, and reported if the battery identified all the issues. Study sample: n = 93 CI-recipients (73 adults, 20 children) and 28 clinicians.

RESULTS

The test battery identified 94% (615/656) of all issues. The test battery and clinician observations agreed in 99% (92/93) of cases on the need for a clinic visit. For 68% (63/93) of cases, the test battery identified all clinician observed issues. The majority (77%, 72/93) of recipients would be satisfied if clinic visits were based on their test battery results. A significantly high proportion agreed that remote monitoring was more convenient than clinic visits and could result in travel, time and cost reductions.

CONCLUSION

This is the first comprehensive test battery designed for CI-recipient remote monitoring.

Cochlear Implantation in NF2 Patients Without Intracochlear Schwannoma Removal

OBJECTIVE

To determine if cochlear implantation without removal of inner ear schwannomas (IES) is an effective treatment option for Neurofibromatosis 2 (NF2) patients. To determine how the presence of an intracochlear schwannoma might impact cochlear implant (CI) outcomes and programming parameters.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary center for cochlear and auditory brainstem implantation.

PATIENTS

Of 10 NF2 patients with IES, 8 are reported with no previous tumor removal on the implanted ear.

INTERVENTIONS

Cochlear implant without tumor removal.

MAIN OUTCOME MEASURES

Performance outcomes with CI at least 1-year post intervention. Programming parameters, including impedances, for patients with IES.

RESULTS

All patients had full insertion of the electrode arrays with round window approaches. Performance outcomes ranged from 0 to 100% for Bamford-Kowal-Bench sentences. Impedance measurements for active electrodes for patients with IES were comparable to those measured in patients without vestibular schwannoma (VS). Only patients who had radiation treatment before receiving their implant had elevated threshold requirements for CI programming compared with CI recipients without VS.

CONCLUSION

Cochlear implantation without tumor removal is an effective option for treating NF2 patients with IES. The presence of an intracochlear tumor did not have an impact on CI performance or programming requirements compared with patients without VS; however, previous treatment with radiation may be related to elevated current requirements in the CI settings.

Identifying Cochlear Implant Channels With Relatively Poor Electrode-Neuron Interfaces Using the Electrically Evoked Compound Action Potential

OBJECTIVES

The primary objective of this study was to quantify local (within ear) and global (between ear) variation in the cochlear implant (CI) electrode-neuron interface (ENI) using the electrically evoked compound action potential (ECAP). We tested the hypothesis that, within an ear, ECAP measures can be used to identify channels with presumed good and poor ENIs, which may be influenced by a combination of spiral ganglion neuron (SGN) density, electrode position, and cochlear resistivity. We also hypothesized that ECAP responses would reflect age-related differences in the global quality of the ENI between younger and older listeners who theoretically differ in SGN density.

DESIGN

Data were obtained from 18 implanted ears (13 individuals) with Advanced Bionics HiRes 90K devices. Six participants (8 ears) were adolescents or young adults (age range: 14-32 years), and 7 participants (10 ears) were older adults (age range: 54-88 years). In each ear, single-channel auditory detection thresholds were measured on channels 2 through 15 in response to a spatially focused electrode configuration (steered quadrupolar; focusing coefficient = 0.9). ECAP amplitudes, amplitude growth function (AGF) slopes, and thresholds were assessed on a subset of channels in each ear in response to three interphase gaps (0, 7, and 30 µs). ECAP peak amplitudes were assessed on all channels between 2 and 15. AGFs and ECAP thresholds were measured on the two nonadjacent channels with the lowest and highest focused behavioral thresholds in each ear. ECAP responses were compared across low- and high-threshold channels and between younger and older CI listeners.

RESULTS

Channels that were estimated to interface poorly with the auditory nerve (i.e., high-focused-threshold channels) had steeper ECAP AGF slopes, smaller dynamic ranges, and higher ECAP thresholds than channels with low focused thresholds. Younger listeners had steeper ECAP AGF slopes and larger ECAP peak amplitudes than older listeners. Moreover, younger listeners showed greater interphase gap sensitivity for ECAP amplitude than older listeners.

CONCLUSIONS

ECAP responses may be used to quantify both local (within ear) and global (between ear) variation in the quality of the ENI. Results of this study support future investigation into the use of ECAP responses in site-selection CI programming strategies. The present results also support a growing body of evidence suggesting that adolescents and young adults with CIs may have denser populations of functional SGNs relative to older adults. Potential differences in global SGN integrity between younger and older listeners warrant investigation of optimal CI programming interventions based on their divergent hearing histories.

Wideband Acoustic Immittance in Cochlear Implant Recipients: Reflectance and Stapedial Reflexes

OBJECTIVES

to characterize differences in wideband power reflectance for ears with and without cochlear implants (CIs), to describe electrically evoked stapedial reflex (eSR)-induced changes in reflectance, and to evaluate the benefit of a broadband probe for reflex threshold determination for CI recipients. It was hypothesized that reflectance patterns in ears with CIs would be consistent with increased middle ear stiffness and that reflex thresholds measured with a broadband probe would be lower compared with thresholds obtained with a single-frequency probe.

DESIGN

Eleven CI recipients participated in both wideband reflectance and eSR testing. Ipsilateral reflexes were measured with three probes: a broadband chirp (swept from 200 to 8000 Hz), a 226 Hz tone, and a 678 Hz tone. Wideband reflectance measures acquired from 28 adults without CIs and with normal middle ear function served as a normative data set for comparison.

RESULTS

Considering the group data, average reflectance was significantly greater for ears with CIs across 250 to 891 Hz and 4238 to 4490 Hz compared with the normative data set, although individual reflectance curves were variable. Some CI recipients also had low 226 Hz admittance, which contributed to the group finding, considering the control group had clinically normal 226 Hz admittance by design. Electrically evoked stapedial reflexes were measurable in nine of 14 ears (64.3%) and in 24 of 46 electrodes (52.5%) tested. Reflex-induced changes in reflectance patterns were unique to the participant/ear, but similar across activators (electrodes) within a given ear. In addition, reflectance values at or above 1000 Hz were affected most by activating the stapedial reflex, even in ears with clinically normal 226 Hz admittance. This is a higher-frequency range than has been reported for acoustically evoked reflex-induced reflectance changes and is consistent with increased middle ear stiffness at rest. Electrically evoked reflexes could be measured more often with the 678 Hz or the broadband probe compared with the 226 Hz probe tone. Although reflex thresholds were lower with the broadband probe compared with the 678 Hz probe in 16 of 24 conditions, this was not a statistically significant finding (Wilcoxon signed-rank test; p = 0.072).

CONCLUSIONS

The applications of wideband acoustic immittance measurements (reflectance and reflexes) should also be considered for ears with CIs. Further work is needed to describe changes across time in ears with CIs to more fully understand the reflectance pattern indicating increased middle ear stiffness and to optimize measuring eSRs with a broadband probe.

Comparison of automated and traditional ECAP recording approaches in clinical practice

OBJECTIVE

The traditional method of recording electrically evoked compound action potentials (ECAPs), as implemented in the MAESTRO clinical software (standard ART), requires manual adjustments during threshold determination through a specialist. The "FineGrain" research tool (FineGrain RT) uses a continuous stimulation paradigm combined with automatic ECAP threshold determination. The aim of this study was to compare the FineGrain RT with standard ART.

DESIGN

ECAPs were recorded with standard ART and the FineGrain RT in paediatric cochlear implant recipients. Different stimulation rates were used for FineGrain ECAP recordings (40, 60, and 76 Hz).

STUDY SAMPLE

Thirteen children (6 - 19 years) participated in this study - nine were bilaterally and four unilaterally implanted, resulting in a total of twenty-two implanted ears.

RESULTS

ECAP threshold determination success rates were similar between the two approaches (92% and 89%) and ECAP thresholds correlated well (r: 0.94, p < 2.2e^-16) with average ART thresholds being lower than FineGrain RT thresholds. FineGrain stimulation with different stimulation rates did not have a significant effect on ECAP thresholds but ECAP thresholds at medial and apical contacts were lower compared to basal contacts.

CONCLUSIONS

TheFineGrain research approach is a reliable replacement for standard ART in clinical practice.

[Psychoacoustic tests for perceptual assessment of processor fitting in patients with cochlear implants]

THE AIM OF THE STUDY

Was to study the possibility of using a battery of psychoacoustic tests to assess the tuning of the cochlear implant processor (CI) in deaf patients.

METHODOLOGY

The study involved 60 prellingually deaf patients aged 10 to 23 years with oral speech skills. To assess the quality of the CI processor tuning, in addition to traditional methods, a special battery of psychoacoustic tests was used. The first block of tests assessed the perception of the basic characteristics of sound signals (duration, temporal structure, spectrum, timbre) and was used to assess the initial setting. The second block of tests, intended for patients with experience using CI, included tasks to distinguish acoustically similar and dynamically changing signals, etc.

RESULTS

At the end of the initial CI setup session, patients with short signal perception problems were identified. Adjusting the frequency of electrical stimulation in patients has increased their ability to distinguish between sounds. During the second tuning session of the CI processor, 6 months later, a group of patients with difficulties in perceiving acoustic information in the low-frequency range was identified - distinguishing melodic intervals, changing the pitch of sounds, highlighting the voice of the target speaker. The «problem» patients underwent additional correction of the CI processor setting and the corresponding auditory training, which improved the test performance and subjective perception of sounds.

CONCLUSION

The use of psychoacoustic tests expands the possibilities of fine tuning the CI processor, taking into account the individual characteristics of the patient's auditory perception at different stages of CI use, especially in «problem» patients.

The Effects of Paired versus Sequential Stimulation on Speech Recognition Outcomes of Adult Cochlear Implant Recipients

PURPOSE

Cochlear implant (CI) sound-processing strategies are important to the overall success of a CI recipient. This study aimed to determine the effects of 2 Advanced Bionics (AB) CI-processing strategies, Optima-S and Optima-P, on speech recognition outcomes in adult CI users.

METHODS

A retrospective chart review was completed at a tertiary academic medical center. Seventeen post-lingually deafened adult CI users (median age = 58.6 years; age range: 23.5-78.9 years) with long-term use of a paired sound-processing strategy (Optima-P) were reprogrammed with a sequential strategy (Optima-S). Demographic data and speech recognition scores with pre- and post-intervention analyses were collected and compared with respect to the 95% confidence interval for common CI word and sentence recognition tests.

RESULTS

Using Optima-S sound-processing strategy, all patients (100%) performed equivalent or better on word and sentence testing than with Optima-P. More specifically, 17.6, 41.2, and 58.8% of the patients performed above the 95% confidence interval for speech recognition conditions of monosyllabic words, sentences in quiet, and sentences in noise, respectively. All patients (100%) selected Optima-S as their preferred strategy for future CI use.

CONCLUSION

Speech recognition performance with Optima-S processing strategy was stable or improved compared to results with Optima-P in all tested conditions, and subjective preference of Optima-S was selected by all patients. Given these results, CI clinicians should consider programming AB CI users with Optima-S sound-processing strategy to optimize overall speech recognition performance.

Real-World Compliance With Follow-up in 2,554 Cochlear Implant Recipients: An Analysis of the HERMES Database

BACKGROUND

Traditional paradigms of care recommend close audiology follow-up and regular speech perception outcomes assessment indefinitely for cochlear implant (CI) recipients after device activation. However, there is scant published data on actual compliance with this paradigm in clinical practice.

METHODS

A multi-center cochlear implant database was queried to identify follow-up rates after cochlear implantation. Follow-up rates where speech perception outcomes assessment occurred at 1-, 3-, 6-, 12-, 18-, and 24-months post-activation were determined by tabulating observed follow-up divided by expected follow-up (O/E ratio) expressed as a percentage. To determine all-cause audiology follow-up rates (with or without testing speech perception outcomes assessment), the database patients from two participating centers (one private practice and one academic center) were similarly analyzed using electronic health record (EHR) data to calculate O/E rates where audiology follow-up occurred for any reason.

RESULTS

O/E follow-up rates where speech perception outcomes assessment occurred was 42, 40, 31, 29, 5, and 22% for 1-, 3-, 6-, 12-, 18-, and 24-months post-activation, respectively (n = 2,554). All-cause audiology follow-up rates (with or without speech perception outcomes assessment) using EHR-confirmed data from two individual centers were 97, 94, 81, 66, 41, and 35% at 1-, 3-, 6-, 12-, 18-, and 24-months post-activation visits, respectively (n = 118).

CONCLUSIONS

Compliance with audiology follow-up and speech perception outcomes assessment is generally low and decreases significantly as time post-activation increases. Future paradigms of care for CI should be designed recognizing the significant attrition that occurs with CI follow-up.

Investigation of an Outcomes-Driven, Computer-Assisted Approach to CI Fitting in Newly Implanted Patients

OBJECTIVE

To evaluate the efficacy of outcomes received by newly implanted cochlear implant recipients when an outcomes-driven, computer-assisted approach to cochlear implantation fitting was used. This approach, referred to as "Fitting to Outcome eXpert," or FOX, was developed by Otoconsult in Antwerp, Belgium.

DESIGN

Thirty-one newly implanted subjects participated in a nonrandomized, single-subject, repeated measures design that involved a within-subject comparison of preoperative and postoperative speech recognition scores. Sound processors for all subjects were programmed using the FOX software that utilized the evidence-based results of various psychoacoustic tests to adjust MAP parameters and improve performance. Additionally, mean word and sentence recognition scores obtained by the subjects programmed with FOX were compared to results obtained by newly implanted patients enrolled in the Nucleus CI532 clinical trial whose devices were programmed using traditional methods.

RESULTS

Subjects whose sound processors were programmed using FOX obtained a mean 6-month postactivation Consonant Nucleus Consonant word score of 60.2% correct. This represented an improvement of 46% age points when mean preactivation and postactivation scores were compared and represented a statistically significant change in score (p < 0.001). This mean score is similar to the mean 6-month Consonant Nucleus Consonant Word score of 61% obtained by 96 subjects enrolled in the Nucleus CI532 trial. Additionally, subjects in this study obtained a mean 6-month postactivation AzBio Sentence score of 42.7% correct when stimuli were presented at 65 dBA using a +10 signal-to-noise ratio. This score is also similar to the mean score of 43% obtained by 96 subjects enrolled in the Nucleus CI532 trial using the same test material and signal-to-noise ratio. Patients enrolled in this study attended 43% fewer programming appointments than the number reported by cochlear implantation centers in recent surveys of clinical care.

CONCLUSION

The results of this study support the use of an outcomes-driven, computer-assisted approach to supplement the management of newly implanted cochlear implant recipients. Subjects whose devices were programmed using such an approach demonstrated mean postoperative word in quiet and sentence in noise scores comparable to those obtained by subjects in the Nucleus CI532 clinical trial whose devices were programmed using traditional programming techniques. Use of this approach positively impacted patient care by reducing the number of postoperative visits needed to optimize sound processor programs, simplified patient testing via the use of direct streaming, and ensured that patients received consistent programming of their sound processor, regardless of the location where the programming was performed.

Auditory Training for Adult Cochlear Implant Users: A Survey and Cost Analysis Study

OBJECTIVES

The aims of this study were as follows: (a) to describe audiologists' practices toward auditory training (AT) for adult cochlear implant (CI) users with a postlingual hearing loss; and (b) to assess the cost of different AT methods for clients and service providers in comparison with no AT delivery.

DESIGN

A survey was distributed to approximately 230 Australian CI audiologists to investigate the range, magnitude, and rationale of AT practices adopted as part of rehabilitation services with adult CI users. The cost of these different AT practices was then estimated from the perspectives of both clients and service providers, and compared against no AT delivery.

RESULTS

Seventy-eight audiologists responded to at least one section of the survey (16% to 33% response rate), of which 85.5% reported that they viewed AT as a necessary component of rehabilitation. Home-based and face-to-face were the methods most frequently adopted to deliver AT. Methods used during training, such as stimuli type, feedback, and encouragement for training adherence, varied across respondents. The cost analysis indicated that home-based training resulted in the lowest program costs, whereas face-to-face AT (when delivered independently from routine appointments) was the method with highest cost for clients and service providers.

CONCLUSIONS

The type of AT, recommended frequency of sessions, and overall duration of programs varied widely across respondents. Costs incurred by clients depended mainly on whether the AT was home-based or clinician-led (i.e., face-to-face, group-based), program fees, and travel arrangements made by clients, as well as clinicians' wages and the method chosen to deliver AT.

The Use of Artificial Intelligence to Program Cochlear Implants

OBJECTIVE

Cochlear implant (CI) technology and techniques have advanced over the years. There has not been the same degree of change in programming and there remains a lack of standardization techniques. The purpose of this study is to compare performance in cochlear implant subjects using experienced clinician (EC) standard programming methods versus an Artificial Intelligence, FOX based algorithm for programming.

STUDY DESIGN

Prospective, nonrandomized, multicenter study using within-subject experimental design SETTING:: Tertiary referral centers.

PATIENTS

Fifty-five adult patients with ≥ 3 months experience with a Nucleus 5, 6, Kanso, or 7 series sound processor.

INTERVENTION

Therapeutic Main Outcome Measures: CNC words and AzBio sentences in noise (+10 dB SNR) tests were administered in a soundproof booth followed by a direct connect psychoacoustic battery using the EC program. Tests were repeated 1 month later using the optimized FOX program. Subjective measures of patient satisfaction were also measured.

RESULTS

Performance for the EC program was compared to the FOX program for both measures. Group mean results revealed equivalent performance (Kruskal-Wallis ANOVA p = 0.934) with both programming methods. While some patients had better performance with the FOX method and some performed more poorly, the majority had equivalent performance and preferred the FOX system.

CONCLUSION

The study demonstrated that on average, FOX outcomes are equivalent to those using traditional programming techniques. In addition, the FOX programming method can effect standardization across centers and increase access for many individuals who could benefit.

Audiologists' preferences in programming cochlear implants: A preliminary report

Background: There is little data available addressing how clinical audiologists handle cochlear implant (CI) programming between device manufacturers and make decisions on related services, particularly in the United States. Objectives: This study sought to understand the techniques and settings professionals use with their patients, how they approach bimodal fitting, which tests they use to evaluate patient and device performance, and their overall preferences of (re)habilitative options. Methods: A questionnaire was developed and distributed to CI audiologists throughout the United States electronically. Results: All respondents reported either always or almost always using Cochlear's default signal processing strategy in contrast to the 64% reported for Med-El and 40% for Advanced Bionics. A trend of less use of electrically evoked stapedial reflex threshold (eSRT) than electrically evoked compound action potentials (eCAP) for objective measures was revealed. Higher likelihood of performing speech recognition tests in quiet than in noise was revealed. Preferences for bimodal fitting trend toward using a partner company's hearing aid, although preferences were comparable in adopting four types of hearing aid formulas surveyed in the questionnaire. Conclusions: These data confirm high variability among audiologists' CI programming practices, and documenting these differences is an important step to understanding how to best treat patients.

Effect of (Mis)Matched Compression Speed on Speech Recognition in Bimodal Listeners

Automatic gain control (AGC) compresses the wide dynamic range of sounds to the narrow dynamic range of hearing-impaired listeners. Setting AGC parameters (time constants and knee points) is an important part of the fitting of hearing devices. These parameters do not only influence overall loudness elicited by the hearing devices but can also affect the recognition of speech in noise. We investigated whether matching knee points and time constants of the AGC between the cochlear implant and the hearing aid of bimodal listeners would improve speech recognition in noise. We recruited 18 bimodal listeners and provided them all with the same cochlear-implant processor and hearing aid. We compared the matched AGCs with the default device settings with mismatched AGCs. As a baseline, we also included a condition with the mismatched AGCs of the participants' own devices. We tested speech recognition in quiet and in noise presented from different directions. The time constants affected outcomes in the monaural testing condition with the cochlear implant alone. There were no specific binaural performance differences between the two AGC settings. Therefore, the performance was mostly dependent on the monaural cochlear implant alone condition.

Improving Localization and Speech Reception in Noise for Bilateral Cochlear Implant Recipients

This study looked at different methods to preserve interaural level difference (ILD) cues for bilateral cochlear implant (BiCI) recipients. One possible distortion to ILD is from automatic gain control (AGC). Localization accuracy of BiCI recipients using default versus increased AGC threshold and linked AGCs versus independent AGCs was examined. In addition, speech reception in noise was assessed using linked versus independent AGCs and enabling and disabling Autosensitivity™ Control. Subjective information via a diary and questionnaire was also collected about maps with linked and independent AGCs during a take-home experience. Localization accuracy improved in the increased AGC threshold and the linked AGCs conditions. Increasing the AGC threshold resulted in a 4° improvement in root mean square error averaged across all speaker locations. Using linked AGCs, BiCI participants experienced an 8° improvement for all speaker locations and a 19° improvement at the speaker location most affected by the AGC. Speech reception threshold in noise improved by an average of 2.5 dB when using linked AGCs versus independent AGCs. In addition, the effect of linked AGCs on speech in noise was compared with that of Autosensitivity™ Control. The Speech, Spatial, and Qualities of Hearing Scale-12 question comparative survey showed an improvement when using maps with linked AGCs. These findings support the hypothesis that ILD cues may be preserved by increasing the AGC threshold or linking AGCs.