Adult Cochlear Implant Users Research Articles

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

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

Speech Perception Outcomes with the Anatomy-Based Fitting Map Among Experienced, Adult Cochlear Implant Users: A Longitudinal Study.

Anatomy-based fitting (ABF), a relatively new technique for cochlear implant programming, attempts to lessen the impact of the electrode insertion location-related frequency-to-place mismatch (FPM). This study aimed to compare vowels and consonant perception in quiet and in noise among experienced adult cochlear implant (CI) users using the ABF and the regular, conventional-based fitting (CBF) map (pre-ABF) over six months. Nine ears from eight experienced adult CI users were included in the experimental and longitudinal research. Using surgical planning software called Otoplan, post-operative computed CT scans were used to determine the locations of intracochlear electrodes and their angle of insertion. The anatomy-based frequency bands were produced by Maestro 9.0 CI fitting software using the Otoplan data. Nonsense syllables with consonant-vowel-consonant (CVC) recognition scores in quiet and noise (+5dB SNR) were compared at baseline, three, and six months after ABF. The vowels involved were /a, i, u/, while the consonants were voiced /b, d, g/ and voiceless /p, t, k/ plosives. Speech pieces were presented at 30 dB SL in a sound-treated room through a loudspeaker positioned at 0° azimuth. On average, the ABF maps shifted center frequency ranging from 0.46 semitones (0.04 octave) at (E12) to 23.94 semitones (1.99 octave) at (E1) as compared to the CBF maps. The mean vowel and consonant identification scores in quiet and in noise were significantly higher in ABF than in CBF (p<0.05) with a large effect size and the trend of improvement was seen with time. Voiced consonants had better scores than the voiceless consonants. The results demonstrated improved perception of vowels and consonants, particularly for sounds containing voicing cues after using the ABF maps. The results also suggested that ABF could be more effective for voice detection in noise. Overall, the findings indicate that correcting place mismatch with an ABF map may improve speech perception, at least among experienced adult cochlear implant users.

International survey of bimodal hearing and bilateral cochlear implant service provision for adults

Objectives As cochlear implant (CI) criteria widen, more candidates with usable residual hearing are being considered for a CI. Unlike children, adults mostly receive only one implant. The aim of this survey was to determine bimodal-hearing and bilateral CI service provision for adults around the world. This survey offers the backdrop against which future clinical practice and service delivery can be considered. Methods CI professionals from across the world were invited to participate in an international multicentre survey. The online questionnaire was circulated to CI professionals in 75 countries. There were 64 respondents, representing 25 countries across five world regions. Results In this sample, adult CI users most had unilateral CI (74.5%) and only 25.5% were bilateral CI users. Some 54% of unilateral CI users used a hearing aid (HA) in the non-implanted ear. Funding for a second implant or HA was not well supported for adult unilateral CI users, and there was no clear practice guidance for fitting and maintaining the contralateral HA in most regions. Conclusions CI professionals recognised the value of fitting contralateral HAs at CI services, with audiology departments and private HA dispensers playing an ongoing role in general maintenance and support.

When to Start Computer-Based Auditory Training After Cochlear Implantation: Effects on Quality of Life and Speech Recognition.

Computer-based auditory training (CBAT) has been shown to improve outcomes in adult cochlear implant (CI) users. This study evaluates in new CI users whether starting CBAT within 3 months of activation or later impacts CI outcomes. Prospective natural experiment. Tertiary academic medical center. Sixty-five new adult CI users. CBAT use over the first-year postactivation. Speech recognition scores and CIQOL-35 Profile score improvements between CI recipients who started CBAT resources early (<3 mo) and late (3-12 mo) postactivation. A total of 43 CI recipients started using CBAT within 3 months postactivation (early) and 22 after 3 months (late). Patients who used CBAT within 3 months postactivation showed significantly greater improvement in consonant-nucleus-consonant words (CNCw) (48.3 ± 24.2% vs 27.8 ± 24.9%; d = 0.84), AzBio Sentences in quiet (55.1 ± 28.0% vs 35.7 ± 36.5%; d = 0.62), and CIQOL-35 listening domain scores (18.2 ± 16.3 vs 6.9 ± 12.9, d = 0.73 [0.023, 1.43]), at 3 months postactivation, compared to those who had not yet initiated CBAT. However, by 12 months postactivation, after which all CI recipients had started CBAT, there were no differences observed between patients who started CBAT early or late in speech recognition scores (CNCw: d = 0.26 [-0.35, 0.88]; AzBio: d = 0.37 [-0.23, 0.97]) or in any CIQOL global or domain score (d-range = 0.014-0.47). Auditory training with self-directed computer software (CBAT) may yield speech recognition and quality-of-life benefits for new adult CI recipients. While early users showed greater improvement in outcomes at 3 months postactivation than users who started later, both groups achieved similar benefits by 12 months postactivation.

Music Perception and Music-Related Quality of Life in Adult Cochlear Implant Users: Exploring the Need for Music Rehabilitation.

Cochlear implant (CI) users face difficulties in accurately perceiving basic musical elements such as pitch, melody, and timbre. Music significantly affects the quality of life (QoL) of CI users. Individually and culturally influenced music perception exceeds psychophysical measures in capturing the subjective music enjoyment of CI users. Understanding the music perception, enjoyment, and habits of CI users is crucial for approaches to improve music-related QoL (MuRQoL). Therefore, this study aims to investigate music perception skills, experiences, and participation in music activities in a large group of adult CI users, and to understand the importance of these factors and their impact on QoL of CI users. This study included 214 CI recipients with diverse auditory experiences who were aged between 18 and 65 years and were unilateral, bimodal, or bilateral users for at least 1 year and 193 normal hearing (NH) controls. All participants completed the information forms and the MuRQoL questionnaire. To assess the impact of music on QoL and identify personalized rehabilitation needs, the scores for each question in both parts of the questionnaire were intersected on a matrix. Data were presented in detail for the CI group and compared between CI and NH groups. A statistically significant difference was found between the matched CI and NH groups in favor of the NH group in terms of music perception and music engagement. Participants who received music education at any point in their lives had significantly higher MuRQoL questionnaire scores. There was no significant relationship found between the duration of auditory rehabilitation, pre-CI hearing aid usage, music listening modality, and MuRQoL questionnaire scores. Unilateral CI users had significantly lower scores in music perception and music engagement subsections compared with bimodal and bilateral CI users. Also, it was found that music had a strong negative impact on QoL in 67/214 of the CI users. Although CI users scored significantly lower than NH individuals on the first part of the questionnaire, which asked about musical skills, enjoyment, and participation in musical activities, findings suggest that CI users value music and music enjoyment just as much. The study reveals the influence of factors such as education level, age, music education, type of hearing loss and auditory rehabilitation on music perception, music enjoyment, and participation in music activities through self-report. The results indicate that for many CI users, music has a strong negative impact on QoL, highlighting the need for personalized music interventions, the inclusion of self-report questionnaires, and music perception tests in clinical evaluations.

Barriers to Early Progress in Adult Cochlear Implant Outcomes.

Adult cochlear implant (CI) recipients obtain varying levels of speech perception from their device. Adult CI users adapt quickly to their CI if they have no peripheral "bottom-up" or neurocognitive "top-down" limiting factors. Our objective here was to understand the influence of limiting factors on the progression of sentence understanding in quiet and in noise, initially and over time. We hypothesized that the presence of limiting factors, detected using a short test battery, would predictably influence sentence recognition with practical consequences. We aimed to validate the test battery by comparing the presence of limiting factors and the success criteria of >90% sentence understanding in quiet 1 month after activation. The study was a single-clinic, cross-sectional, retrospective design incorporating 32 adult unilateral Nucleus CI users aged 27 to 90 years (mean = 70, SD = 13.5). Postoperative outcome was assessed through sentence recognition scores in quiet and in varying signal to noise ratios at 1 day, 1 to 2 months, and up to 2 years. Our clinic's standard test battery comprises physiological and neurocognitive measures. Physiological measures included electrically evoked compound action potentials for recovery function, spread of excitation, and polarity effect. To evaluate general cognitive function, inhibition, and phonological awareness, the Montreal Cognitive Assessment screening test, the Stroop Color-Word Test, and tests 3 and 4 of the French Assessment of Reading Skills in Adults over 16 years of age, respectively were performed. Physiological scores were considered abnormal, and therefore limiting, when total neural recovery periods and polarity effects, for both apical and basal electrode positions, were >1.65 SDs from the population mean. A spread of excitation of >6 electrode units was also considered limiting. For the neurocognitive tests, scores poorer than 1.65 SDs from published normal population means were considered limiting. At 1 month, 13 out of 32 CI users scored ≥90% sentence recognition in quiet with no significant dependence on age. Subjects with no limiting peripheral or neurocognitive factors were 8.5 times more likely to achieve ≥90% score in quiet at 1 month after CI switch-on (p = 0.010). In our sample, we detected 4 out of 32 cases with peripheral limiting factors that related to neural health or poor electrode-neural interface at both apical and basal positions. In contrast, neurocognitive limiting factors were identified in 14 out of 32 subjects. Early sentence recognition scores were predictive of long-term sentence recognition thresholds in noise such that limiting factors appeared to be of continuous influence. Both peripheral and neurocognitive processing factors affect early sentence recognition after CI activation. Peripheral limiting factors may have been detected less often than neurocognitive limiting factors because they were defined using sample-based criteria versus normal population-based criteria. Early performance was generally predictive of long-term performance. Understanding the measurable covariables that limit CI performance may inform follow-up and improve counseling. A score of ≥90% for sentence recognition in quiet at 1 month may be used to define successful progress; whereas, lower scores indicate the need for diagnostic testing and ongoing rehabilitation. Our findings suggest that sentence test scores as early as 1 day after activation can provide vital information for the new CI user and indicate the need for rehabilitation follow-up.

Generic and Hearing-Specific Quality of Life in Older Adult Cochlear Implant Users.

Background This study aimed to evaluate the quality of life (QOL) of older adults using cochlear implants (CIs) by focusing on how individual characteristics and speech perception are related to generic QOL ratings and utilizing the Health Utilities Index Mark III (HUI3) for assessment. Methodology A cross-sectional study was conducted with 19 participants aged ≥60 years, who were within one to five years post-implant activation. Data were obtained through self-administered questionnaires, including the HUI3 for generic QOL assessment and disease-specific indexes. Speech perception tests and chart reviews provided personal characteristic data. Statistical analysis was performed using the Mann-Whitney U-test, one-way analysis of variance, and Pearson's correlation coefficient. Results In total, 18 patients responded to the study. This study revealed that the generic QOL in older adult CI users was lower than that in the general older adult population. There was no significant association between QOL and variables such as sex, duration of implant usage, or age. However, a longer duration of hearing loss before receiving an implant was associated with higher generic QOL scores. Additionally, a strong correlation was observed between the hearing-related QOL score and utility scores. Conclusions Longer pre-implantation hearing loss correlated with better post-implantation QOL. Additionally, a reduced QOL, specifically within the hearing attribute, a subdomain of the HUI3, was associated with a lower overall generic QOL. The results suggest that generic QOL cannot be evaluated based on hearing ability alone and that cochlear implantation does not completely improve generic QOL. This study represents an important first step in understanding the QOL of older adult CI users from a variety of backgrounds.

Intraoperative Compound Action Potentials as a Predictor of Postoperative Cortical Auditory Evoked Potentials in Cochlear Implant Users.

Electrically evoked cortical auditory evoked potentials (ECAEPs) are central brain responses to auditory stimuli that correlate with postoperative cochlear implant (CI) hearing outcomes. They differ from electrically evoked compound action potentials (ECAPs) which are peripheral responses that can be elicited intraoperatively and may also predict CI hearing outcomes. It is not known to what degree ECAP and ECAEP responses are associated with each other. Such a correlation, if present, may allow for an earlier and more accurate prediction of postoperative hearing outcomes. This retrospective study involved 42 adult CI users. Threshold levels and amplitude growth function slopes of intraoperative ECAPs were compared to the latencies and peak-to-peak amplitudes of postoperative ECAEP responses at three different cochlear electrode array sites (apical, medial, and basal). A weak positive relationship was found between intraoperative ECAP thresholds and ECAEP N1-P2 peak-to-peak amplitude (r = 0.301, p = 0.005). Time between ECAP and ECAEP measurements was weakly correlated with P1-N1 peak-to-peak amplitude (r = 0.321, p = 0.002) and ECAEP N1-P2 peak-to-peak amplitude (r = 0.340, p = 0.001). ECAP amplitude growth function slopes varied by electrode location (χ2 = 26.701, df = 2, p = 0. 000002). These results suggest that intraoperative ECAP responses do not robustly predict postoperative ECAEP responses, providing caution against the use of ECAPs as a predictive tool for CI hearing outcomes.

Evaluating Changes in Adult Cochlear Implant Users' Brain and Behavior Following Auditory Training.

To describe the effects of two types of auditory training on both behavioral and physiological measures of auditory function in cochlear implant (CI) users, and to examine whether a relationship exists between the behavioral and objective outcome measures. This study involved two experiments, both of which used a within-subject design. Outcome measures included behavioral and cortical electrophysiological measures of auditory processing. In Experiment I, 8 CI users participated in a music-based auditory training. The training program included both short training sessions completed in the laboratory as well as a set of 12 training sessions that participants completed at home over the course of a month. As part of the training program, study participants listened to a range of different musical stimuli and were asked to discriminate stimuli that differed in pitch or timbre and to identify melodic changes. Performance was assessed before training and at three intervals during and after training was completed. In Experiment II, 20 CI users participated in a more focused auditory training task: the detection of spectral ripple modulation depth. Training consisted of a single 40-minute session that took place in the laboratory under the supervision of the investigators. Behavioral and physiologic measures of spectral ripple modulation depth detection were obtained immediately pre- and post-training. Data from both experiments were analyzed using mixed linear regressions, paired t tests, correlations, and descriptive statistics. In Experiment I, there was a significant improvement in behavioral measures of pitch discrimination after the study participants completed the laboratory and home-based training sessions. There was no significant effect of training on electrophysiologic measures of the auditory N1-P2 onset response and acoustic change complex (ACC). There were no significant relationships between electrophysiologic measures and behavioral outcomes after the month-long training. In Experiment II, there was no significant effect of training on the ACC, although there was a small but significant improvement in behavioral spectral ripple modulation depth thresholds after the short-term training. This study demonstrates that auditory training improves spectral cue perception in CI users, with significant perceptual gains observed despite cortical electrophysiological responses like the ACC not reliably predicting training benefits across short- and long-term interventions. Future research should further explore individual factors that may lead to greater benefit from auditory training, in addition to optimization of training protocols and outcome measures, as well as demonstrate the generalizability of these findings.

Neurocognitive outcomes in young adults with cochlear implants: The role of early language access and crossmodal plasticity

Many children with profound hearing loss have received cochlear implants (CI) to help restore some sense of hearing. There is, however, limited research on long-term neurocognitive outcomes in young adults who have grown up hearing through a CI. This study compared the cognitive outcomes of early-implanted (n = 20) and late-implanted (n = 21) young adult CI users, and typically hearing (TH) controls (n=56), all of whom were enrolled in college. Cognitive fluidity, nonverbal intelligence, and American Sign Language (ASL) comprehension were assessed, revealing no significant differences in cognition and nonverbal intelligence between the early and late-implanted groups. However, there was a difference in ASL comprehension, with the late-implanted group having significantly higher ASL comprehension. Although young adult CI users showed significantly lower scores in a working memory and processing speed task than TH age-matched controls, there were no significant differences in tasks involving executive function shifting, inhibitory control, and episodic memory between young adult CI and young adult TH participants. In an exploratory analysis of a subset of CI participants (n = 17) in whom we were able to examine crossmodal plasticity, we saw greater evidence of crossmodal recruitment from the visual system in late-implanted compared with early-implanted CI young adults. However, cortical visual evoked potential latency biomarkers of crossmodal plasticity were not correlated with cognitive measures or ASL comprehension. The results suggest that in the late-implanted CI users, early access to sign language may have served as a scaffold for appropriate cognitive development, while in the early-implanted group early access to oral language benefited cognitive development. Furthermore, our results suggest that the persistence of crossmodal neuroplasticity into adulthood does not necessarily impact cognitive development. In conclusion, early access to language – spoken or signed – may be important for cognitive development, with no observable effect of crossmodal plasticity on cognitive outcomes.

The role of inhibitory control in spoken word recognition: evidence from cochlear implant users

ABSTRACT During spoken word recognition, listeners must quickly map sounds to meaning while suppressing competitors. It remains unclear whether domain-general inhibitory control is recruited for resolving lexical competition. Cochlear implant (CI) users present a unique population for addressing this question because they are consistently confronted with degraded auditory input, and may need to rely on domain-general mechanisms to compensate. We examined word recognition in adult CI users who were prelingually deaf (lost their hearing in childhood, N = 21), postlingually deaf (lost their hearing in adulthood, N = 50), and normal hearing controls (NH; N = 71). Participants recognised words during an eye-tracking task and completed an inhibitory control task. CI users were slower to recognise words and did not resolve competition as fully. Better inhibitory control predicted faster word activation in NH controls and postlingual, but not prelingual, CI users. Prolonged experience with acoustic language may thus influence how domain-general mechanisms are recruited for language processing.

Greater working memory in cochlear implant users is related to higher subjective quality of life

IntroductionA common concern for individuals with moderate-to-profound hearing loss who have received a cochlear implants (CIs) is difficulty following conversations in noisy environments. A possible reason is the increased use of cognitive resources (attention and working memory) to disambiguate the speech stimuli potentially causing detriments in functional aspects of life. However, this relationship is not well-documented. The overall arching goal of this study was to quantify the relationships between Patient-Reported Outcome Measures (PROMs) and cognitive ability through working memory and speech perception measures.MethodsIn the current study, 31 adult CI users and typical hearing (TH) age-matched controls were recruited. CI users completed PROMs including Speech, Spatial and Quality of hearing survey (SSQ) and versions of a quality of life (QOL) for CI users (CIQOL) and Nijmegen Cochlear Implant Questionnaire (NCIQ). Measures of cognition were assessed using internet-based tools. Outcomes were compared between groups and PROMs and were related to the cognitive tasks.ResultsReduced auditory working memory and speech perception in noise were observed in CI users compared to TH controls. Correlation analyses revealed significant domain-specific PROM relationships with cognitive tasks in CI users, but not in TH controls. The SSQ had more significant relationships compared to the other PROMS.ConclusionThese results suggest that internet-based metrics of cognitive ability are associated with the functional hearing aspects of life in CI users and that SSQ is more sensitive to investigate the cognitive related effects of QOL compared to other commonly used PROMs.

Impact of ASL Exposure on Spoken Phonemic Discrimination in Adult CI Users: A Functional Near-Infrared Spectroscopy Study

Abstract We examined the impact of exposure to a signed language (American Sign Language, or ASL) at different ages on the neural systems that support spoken language phonemic discrimination in deaf individuals with cochlear implants (CIs). Deaf CI users (N = 18, age = 18–24 yrs) who were exposed to a signed language at different ages and hearing individuals (N = 18, age = 18–21 yrs) completed a phonemic discrimination task in a spoken native (English) and non-native (Hindi) language while undergoing functional near-infrared spectroscopy neuroimaging. Behaviorally, deaf CI users who received a CI early versus later in life showed better English phonemic discrimination, albeit phonemic discrimination was poor relative to hearing individuals. Importantly, the age of exposure to ASL was not related to phonemic discrimination. Neurally, early-life language exposure, irrespective of modality, was associated with greater neural activation of left-hemisphere language areas critically involved in phonological processing during the phonemic discrimination task in deaf CI users. In particular, early exposure to ASL was associated with increased activation in the left hemisphere’s classic language regions for native versus non-native language phonemic contrasts for deaf CI users who received a CI later in life. For deaf CI users who received a CI early in life, the age of exposure to ASL was not related to neural activation during phonemic discrimination. Together, the findings suggest that early signed language exposure does not negatively impact spoken language processing in deaf CI users, but may instead potentially offset the negative effects of language deprivation that deaf children without any signed language exposure experience prior to implantation. This empirical evidence aligns with and lends support to recent perspectives regarding the impact of ASL exposure in the context of CI usage.

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

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. 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. 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. 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.

Enhancing Use of Remote Microphones Among Adult Cochlear Implant Users and Their Frequent Communication Partners

Remote microphones serve as assistive devices with the potential to enhance speech perception and sound quality for cochlear implant (CI) users in challenging listening environments. However, the extent to which adult CI users and their communication partners perceive these benefits remains uncertain. To address this question, we organized support groups for adult CI recipients implanted at the University of Iowa Hospitals and Clinics and their partners residing. The primary objectives of these support groups were twofold: firstly, to provide comprehensive education on the benefits of utilizing remote microphones, and secondly, to facilitate discussions on pertinent topics, including troubleshooting device-related issues. This study focuses on identifying and addressing the barriers encountered by adult CI users and their communication partners in effectively utilizing remote microphones, while simultaneously promoting their proper use through education and guidance. During the support group sessions, we engaged in discussions focused on strategies for optimizing remote microphone utilization among CI users and their frequent communication partners. These strategies encompassed comprehensive education and training, technical assistance, addressing concerns and potential stigma, and involving family members and caregivers in the process. Following participation in the support group sessions, all attendees completed questionnaires indicating an increased motivation to utilize remote microphones effectively. This finding underscores the critical role of education and support in promoting the efficient use of assistive devices and ultimately enhancing communication outcomes for both CI recipients and their communication partners. In summary, this project indicates the potential advantages of incorporating remote microphones into the lives of adult CI recipients and their communication partners. It underscores the imperative need for robust education and support mechanisms to ensure the optimal utilization of remote microphone systems.

Integrating Emotion Perception in Rehabilitation Programs for Cochlear Implant Users: A Call for a More Comprehensive Approach.

Postoperative rehabilitation programs for cochlear implant (CI) recipients primarily emphasize enhancing speech perception. However, effective communication in everyday social interactions necessitates consideration of diverse verbal social cues to facilitate language comprehension. Failure to discern emotional expressions may lead to maladjusted social behavior, underscoring the importance of integrating social cues perception into rehabilitation initiatives to enhance CI users' well-being. After conventional rehabilitation, CI users demonstrate varying levels of emotion perception abilities. This disparity notably impacts young CI users, whose emotion perception deficit can extend to social functioning, encompassing coping strategies and social competence, even when relying on nonauditory cues such as facial expressions. Knowing that emotion perception abilities generally decrease with age, acknowledging emotion perception impairments in aging CI users is crucial, especially since a direct correlation between quality-of-life scores and vocal emotion recognition abilities has been observed in adult CI users. After briefly reviewing the scope of CI rehabilitation programs and summarizing the mounting evidence on CI users' emotion perception deficits and their impact, we will present our recommendations for embedding emotional training as part of enriched and standardized evaluation/rehabilitation programs that can improve CI users' social integration and quality of life. Evaluating all aspects, including emotion perception, in CI rehabilitation programs is crucial because it ensures a comprehensive approach that enhances speech comprehension and the emotional dimension of communication, potentially improving CI users' social interaction and overall well-being. The development of emotion perception training holds promises for CI users and individuals grappling with various forms of hearing loss and sensory deficits. Ultimately, adopting such a comprehensive approach has the potential to significantly elevate the overall quality of life for a broad spectrum of patients.

Psychoacoustic and electroencephalographic responses to changes in amplitude modulation depth and frequency in relation to speech recognition in cochlear implantees

Temporal envelope modulations (TEMs) are one of the most important features that cochlear implant (CI) users rely on to understand speech. Electroencephalographic assessment of TEM encoding could help clinicians to predict speech recognition more objectively, even in patients unable to provide active feedback. The acoustic change complex (ACC) and the auditory steady-state response (ASSR) evoked by low-frequency amplitude-modulated pulse trains can be used to assess TEM encoding with electrical stimulation of individual CI electrodes. In this study, we focused on amplitude modulation detection (AMD) and amplitude modulation frequency discrimination (AMFD) with stimulation of a basal versus an apical electrode. In twelve adult CI users, we (a) assessed behavioral AMFD thresholds and (b) recorded cortical auditory evoked potentials (CAEPs), AMD-ACC, AMFD-ACC, and ASSR in a combined 3-stimulus paradigm. We found that the electrophysiological responses were significantly higher for apical than for basal stimulation. Peak amplitudes of AMFD-ACC were small and (therefore) did not correlate with speech-in-noise recognition. We found significant correlations between speech-in-noise recognition and (a) behavioral AMFD thresholds and (b) AMD-ACC peak amplitudes. AMD and AMFD hold potential to develop a clinically applicable tool for assessing TEM encoding to predict speech recognition in CI users.

The EEG N400 component as a marker of language acquisition and processing in cochlear implant users

Language processing can be measured objectively using late components in the evoked brain potential. The most established component in this area of research is the N400 component, a negativity that peaks at about 400 ms after stimulus onset with a centro-parietal maximum. It reflects semantic processing. Its presence, as well as its temporal and quantitative expression, allows to conclude about the quality of processing. It is therefore suitable for measuring speech comprehension in special populations, such as cochlear implant (CI) users. The following is an overview of the use of the N400 component as a tool for studying language processes in CI users. We present studies with adult CI users, where the N400 reflects the quality of speech comprehension with the new hearing device and we present studies with children where the emergence of the N400 component reflects the acquisition of their very first vocabulary.

Peripheral Neural Synchrony in Postlingually Deafened Adult Cochlear Implant Users.

This paper reports a noninvasive method for quantifying neural synchrony in the cochlear nerve (i.e., peripheral neural synchrony) in cochlear implant (CI) users, which allows for evaluating this physiological phenomenon in human CI users for the first time in the literature. In addition, this study assessed how peripheral neural synchrony was correlated with temporal resolution acuity and speech perception outcomes measured in quiet and in noise in postlingually deafened adult CI users. It tested the hypothesis that peripheral neural synchrony was an important factor for temporal resolution acuity and speech perception outcomes in noise in postlingually deafened adult CI users. Study participants included 24 postlingually deafened adult CI users with a Cochlear™ Nucleus® device. Three study participants were implanted bilaterally, and each ear was tested separately. For each of the 27 implanted ears tested in this study, 400 sweeps of the electrically evoked compound action potential (eCAP) were measured at four electrode locations across the electrode array. Peripheral neural synchrony was quantified at each electrode location using the phase-locking value (PLV), which is a measure of trial-by-trial phase coherence among eCAP sweeps/trials. Temporal resolution acuity was evaluated by measuring the within-channel gap detection threshold (GDT) using a three-alternative, forced-choice procedure in a subgroup of 20 participants (23 implanted ears). For each ear tested in these participants, GDTs were measured at two electrode locations with a large difference in PLVs. For 26 implanted ears tested in 23 participants, speech perception performance was evaluated using consonant-nucleus-consonant (CNC) word lists presented in quiet and in noise at signal to noise ratios (SNRs) of +10 and +5 dB. Linear Mixed effect Models were used to evaluate the effect of electrode location on the PLV and the effect of the PLV on GDT after controlling for the stimulation level effects. Pearson product-moment correlation tests were used to assess the correlations between PLVs, CNC word scores measured in different conditions, and the degree of noise effect on CNC word scores. There was a significant effect of electrode location on the PLV after controlling for the effect of stimulation level. There was a significant effect of the PLV on GDT after controlling for the effects of stimulation level, where higher PLVs (greater synchrony) led to lower GDTs (better temporal resolution acuity). PLVs were not significantly correlated with CNC word scores measured in any listening condition or the effect of competing background noise presented at an SNR of +10 dB on CNC word scores. In contrast, there was a significant negative correlation between the PLV and the degree of noise effect on CNC word scores for a competing background noise presented at an SNR of +5 dB, where higher PLVs (greater synchrony) correlated with smaller noise effects on CNC word scores. This newly developed method can be used to assess peripheral neural synchrony in CI users, a physiological phenomenon that has not been systematically evaluated in electrical hearing. Poorer peripheral neural synchrony leads to lower temporal resolution acuity and is correlated with a larger detrimental effect of competing background noise presented at an SNR of 5 dB on speech perception performance in postlingually deafened adult CI users.

Manual switching between programs intended for specific real-life listening environments by adult cochlear implant users: do they use the intended program?

Objective The aim of the current study was to investigate the use of manually and automatically switching programs in everyday day life by adult cochlear implant (CI) users Design Participants were fitted with an automatically switching sound processor setting and 2 manual programs for 3-week study periods. They received an extensive counselling session. Datalog information was used to analyse the listening environments identified by the sound processor, the program used and the number of program switches. Study samples Fifteen adult Cochlear CI users. Average age 69 years (range: 57–85 years). Results Speech recognition in noise was significantly better with the “noise” program than with the “quiet” program. On average, participants correctly classified 4 out of 5 listening environments in a laboratory setting. Participants switched, on average, less than once a day between the 2 manual programs and the sound processor was in the intended program 60% of the time. Conclusion Adult CI users switch rarely between two manual programs and leave the sound processor often in a program not intended for the specific listening environment. A program that switches automatically between settings, therefore, seems to be a more appropriate option to optimise speech recognition performance in daily listening environments.