Cochlear Implant Research Articles

Concurrent Cognitive Task Alters Postural Control Performance of Young Adults With Unilateral Cochlear Implants.

The aim of this study was to investigate the balance performances of young adults with unilateral cochlear implants (CIs) in a dual-task condition. Fifteen young adults with unilateral CIs and 15 healthy individuals were included in the study. The balance task was applied using the Sensory Organization Test via Computerized Dynamic Posturography. The Backward Digit Recall task was applied as an additional concurrent cognitive task. In the balance task, participants completed four different conditions, which gradually became more difficult: Condition 1: fixed platform, eyes open; Condition 3: fixed platform, eyes open and visual environment sway; Condition 4: platform sway, eyes open; Condition 6: platform sway, eyes open and visual environment sway. To evaluate the dual-task condition performance, participants were given cognitive and motor tasks simultaneously. Visual (p = .016), vestibular (p < .001), and composite balance scores (p < .001) of CI users were statistically significantly lower than the control group. Condition 3 (p = .003), Condition 4 (p = .007), and Condition 6 (p < .001) balance scores of CI users in the single-task condition were statistically significantly lower than controls. Condition 6 (p < .001) balance scores of CI users in the dual-task condition were statistically significantly lower than the control group. Condition 1 score (p = .002) of the CI users in the dual-task condition showed a statistically significant decrease compared to the balance score in the single-task condition, while the Condition 6 score (p = .011) in the dual-task condition was statistically significantly higher than the balance score in the single-task condition. The balance performance of individuals with CIs in the dual-task condition was worse than typical healthy individuals. It can be suggested that dual-task performances should be included in the vestibular rehabilitation process in CI users in the implantation process in terms of balance abilities in multitasking conditions and risk of falling.

Making a Difference from Day One: The Urgent Need for Universal Neonatal Hearing Screening

Neonatal hearing screening (NHS) is a critical public health measure for early identification of hearing loss, ensuring timely access to interventions that can dramatically improve a child’s language development, cognitive abilities, and social inclusion. Beyond clinical benefits, NHS provides long-term advantages in education and quality of life. Given that congenital hearing loss affects approximately 1–2 in every 1000 newborns worldwide, the case for universal screening is clear. Countries like the United States and Australia have successfully implemented NHS, leading to earlier diagnoses, improved language development, and better educational outcomes. In Europe, while many nations have adopted NHS, consistency remains a challenge. Countries such as Norway and the United Kingdom stand out for their well-established systems, whereas others, like Greece, have made notable progress but have yet to mandate NHS nationwide. This highlights the need for cohesive national policies across Europe to ensure universal coverage. Screening methods such as Transient Evoked Otoacoustic Emissions (TEOAE) and Automated Auditory Brainstem Response (AABR) are established tools for detecting hearing impairments in neonates. Despite their demonstrated efficacy, NHS remains inconsistent globally, particularly in low- and middle-income regions that lack mandatory policies or access to reliable screening technologies. This perspective advocates for the urgent need to make NHS mandatory in all countries, emphasizing its societal benefits and cost-effectiveness. Early diagnosis supports prompt intervention, like hearing aids or cochlear implants, which are most effective when implemented before six months. It also empowers families to make informed decisions, fosters educational inclusion, and mitigates the social and emotional challenges of undiagnosed hearing loss. Policymakers, healthcare providers, and international organizations must prioritize universal NHS to ensure no child is left behind due to unaddressed hearing loss.

How to Teach an "Old Dog" New Tricks: Improving Clinical Efficiency in a Well-Established Cochlear Implant Program.

To evaluate the implementation of a new streamlined service delivery model for cochlear implant (CI) patients at a mature academic CI program. Tertiary referral center. CI candidates and CI users. Implementation of a new CI service delivery model. CI surgical numbers, conversion rate from CI evaluation to surgery, documentation time, number of visits for new versus established CI users, ratio of CI clinical full-time equivalency to CI surgical numbers, time from CI referral to CI evaluation, patient travel burden. De-identified data from the electronic health record (EHR) were used to develop an efficiency improvement plan. With the old clinical model, audiologists' schedules were at capacity, wait for CI evaluation appointments was prolonged, and CI surgical numbers were declining. The new model implemented an interactive electronic medical record, a de-escalated postoperative programming schedule, inclusion of telehealth pre-CI surgery, and an evidence-based approach to CI programming. After a 4-year time period (2019-2022) of implementing clinical improvement strategies, the postoperative CI programming schedule in the first year after activation was reduced from 10 visits (unilateral CI user) and 16 visits (bilateral CI user) to 4 visits total. This saved the patient up to 16 hours of time at the clinic, reduced travel burden, and opened 19 weeks of appointment slots for new patients. Increased utilization of the EHR and telehealth increased the conversion rate from CI evaluation to CI surgery by 33% and decreased the no-show rate by 5%. Annual CI surgical numbers subsequently increased by 45% with the new model, which increased our program's CI utilization rate and reduced our role as a barrier to CI care. If CI programs wish to be instrumental in improving CI utilization rates, clinical care models need to be adapted now in preparation for the projected rise in the number of potential CI candidates. This streamlined clinical efficiency model serves as an example of patient-centered CI care that can be recreated at other institutions. Outcomes from our 4-year strategic initiative will add to the scarcity of literature in this area.

Perception of voice cues and speech-in-speech by children with prelingual single-sided deafness and a cochlear implant

Voice cues, such as fundamental frequency (F0) and vocal tract length (VTL), help listeners identify the speaker's gender, perceive the linguistic and emotional prosody, and segregate competing talkers. Postlingually implanted adult cochlear implant (CI) users seem to have difficulty in perceiving and making use of voice cues, especially of VTL. Early implanted child CI users, in contrast, perceive and make use of both voice cues better than CI adults, and in patterns similar to their peers with normal hearing (NH).In our study, we investigated the perception and use of voice cues in children with single-sided deafness (SSD) who received their CI at an early age (SSD+CI), in an attempt to bridge the gap between these two groups. The SSD+CI children have access to bilateral auditory information and often receive their CI at an early age, similar to CI children. They may also have dominant acoustic representations, similar to CI adults who acquired hearing loss at a later age. As such, the current study aimed to investigate the perception and use of voice cues by a group of nine early-implanted children with prelingual SSD. The study consisted of three experiments: F0 and VTL discrimination, voice gender categorization, and speech-in-speech perception. In each experiment, the results of the SSD group are compared to children and adults with CIs (for their CI ear) and with typical hearing (for their NH ear).Overall, the SSD+CI children had poorer VTL detection thresholds with their CI compared to their NH ear, while their F0 perception was similar across ears. Detection thresholds for both F0 and VTL with their CI ear was comparable to those of bilaterally implanted CI children, suggesting that SSD+CI children do not only rely on their NH ear, but actually make use of their CI. SSD+CI children relied more heavily on F0 cues than on VTL cues for voice gender categorization, with cue weighting patterns comparable to those of CI adults. In contrast to CI children, the SSD+CI children showed limited speech perception benefit based on F0 and VTL differences between the target and masker speaker, which again corresponded to the results of CI adults. Altogether, the SSD+CI children make good use of their CI, despite a good-hearing ear, however, the perceptual patterns seem to fall in-between those of CI children and CI adults. Perhaps a combination of childhood neuroplasticity, limited experience with relying only on the CI, and a dominant acoustic representation of voice gender explain these results.

Silicone-based AC102-loaded cochlear implant coatings protect residual hearing in an animal model of cochlear implantation

Cochlear implant users with residual hearing benefit synergistically from combined electrical stimulation via the cochlear implant and preserved residual hearing after surgery. However, direct mechanical trauma and subsequent inflammation may deteriorate hearing function. AC102, a novel otoprotective pyridoindole with anti-apoptotic and anti-oxidative properties significantly improved hearing recovery following cochlear implantation when administered intratympanically prior to surgery. Additionally, AC102 exerts neurotrophic effects, possibly aiding in the preservation of auditory nerve fibers and spiral ganglion neurons. Rapid clearance of the drug, however, might be a limiting factor to further attenuate the inflammatory response and maintain neuronal health. The aim of the current study was to design an AC102-loaded electrode array for sustained drug delivery and investigate its effects in hearing preservation cochlear implantation.First, the release-kinetics of AC102 were investigated in vitro and modelled by the Higuchi equation of drug release. An electrode array coated with 10% AC102 was manufactured, its release kinetics evaluated, and subsequently tested in vivo. 20 normal hearing Mongolian gerbils were unilaterally implanted with an AC102-loaded or an unloaded control electrode. Compound action potentials were measured prior to cochlear implantation and serially over 28 days. Hair cells, inner hair cell synapses, and auditory nerve fibers were quantified in cochlear whole-mounts by immunofluorescence staining.AC102 release from silicone coating could be predictably modelled by the Higuchi equation of drug release. The electrode array with an AC102-silicone depot enabled non-linear sustained drug release with initially higher release concentrations. In vivo, the AC102-loaded electrode array significantly recovered auditory threshold shifts near the maximum insertion depth over 28 days. In the apical region, a significant recovery was noticed only until day 14, after which threshold shifts aligned between groups. Histologically, AC102-loaded electrodes significantly preserved outer hair cells apical of the maximum insertion depth and inner hair cells and neuronal structures at the tip of the inserted electrode.In conclusion, the drug-loaded electrode arrays could predictably release AC102 over a period of 28 days. AC102 enabled the restoration of auditory thresholds near the area of maximum insertion, which is the desired region to be preserved in cochlear implant recipients with residual hearing.

Hearing preservation in pediatric cochlear implantation.

Pediatric cochlear implantation has evolved considerably over the past three decades to include more patients at earlier ages with greater degrees of residual hearing. As an extension, a significant focus of research over the past decade has surrounded preservation of existing acoustic hearing. Multiple studies published within the last 5 years demonstrate aidable acoustic hearing preservation in 60-90% of pediatric patients, with 40-60% experiencing complete hearing preservation following cochlear implantation. Durability of preserved hearing varies among patients, with some patients losing residual hearing within 1 year of surgery whereas others maintain acoustic hearing through at least 5 years of follow-up. Speech outcomes appear superior among patients with preserved acoustic hearing, particularly in the presence of background noise. Several recent studies suggest a music appreciation advantage in children with preserved acoustic hearing following cochlear implantation. Hearing preservation rates during cochlear implantation in children matches, if not often exceeds, hearing preservation rates observed among adults. Preservation of acoustic hearing during cochlear implantation confers multiple advantages for the pediatric population. Beyond improved speech understanding and music appreciation, minimizing intracochlear trauma and resultant scarring facilitates potential future regenerative treatments or revision surgery.

Screening for Developmental Delays in Pediatric Cochlea Implant Candidates and Recipients.

Conduct a pilot clinical improvement project to effectively screen children with hearing loss for developmental delays. Children with hearing loss and cochlear implants (CIs) are at risk for additional developmental delays; however, screening to aid in early identification and referral for developmental delays is not routinely performed at CI centers. It is important to consider all aspects of child development to maximize CI outcomes and access to language. Caregivers of 31 children completed the Ages and Stages Questionnaire (ASQ) and the Sensory Profile-2 (SP2), which are standardized questionnaires that assess developmental milestones in areas of communication, gross motor, fine motor, problem solving, personal-social, and sensory integration. Participants were prospectively evaluated at a CI center in a tertiary medical center. Participants included children, aged ≤5 years old with bilateral hearing loss who use CIs or who were CI candidates, and their families. Scores on ASQ and SP2 questionnaires. Thirty-one children were screened, and approximately 40 to 50% screened positive for risk of developmental delay in areas excluding communication and received referrals for evaluations in occupational therapy (n = 16; 51.6%), physical therapy (n = 13; 41.9%), and developmental pediatrics (n = 13; 41.9%). Of children referred and seen for evaluations, six were diagnosed with developmental delays in at least one developmental area beyond the communication domains. Routine screening in children with significant hearing loss can successfully detect developmental delays, which may go unnoticed. This proactive approach enables timely and comprehensive treatment for developmental delays beyond those solely related to communication.

Hybrid Cochlear Implant Outcomes and Improving Outcomes With Electric-Acoustic Stimulation.

Electric-acoustic stimulation (EAS) provides cochlear implant (CI) recipients with preserved low-frequency acoustic hearing in the implanted ear affording auditory cues not reliably transmitted by the CI including fundamental frequency, temporal fine structure, and interaural time differences (ITDs). A prospective US multicenter clinical trial was conducted examining the safety and effectiveness of a hybrid CI for delivering EAS. Fifty-two adults (mean age 59.9 yr) were enrolled in the study and followed up to 5 years postactivation. Testing included unaided and aided audiometric thresholds, speech perception (Consonant-Nucleus-Consonant [CNC] words in quiet and AzBio sentences +5 dB SNR), and patient-reported outcomes (Speech, Spatial, and Qualities of Hearing Scale). Functionally aidable hearing, defined as low-frequency pure-tone average (125-500 Hz) <80 dB HL, was maintained for 77% of patients through 1 year, with 66.7% maintaining through 5 years. Speech perception was significantly improved at all postoperative timepoints compared with preoperative performance with hearing aid(s), and patient-reported outcomes indicated significantly improved subjective speech understanding, spatial hearing, and sound quality. Participants with preserved acoustic hearing using EAS reported significantly higher subjective spatial hearing and sound quality than participants with electric-only hearing in the implanted ear. Patients with high-frequency hearing loss demonstrate significant long-term benefit with a hybrid CI including high rates of functional hearing preservation, significantly improved speech perception, and subjective patient-reported outcomes. EAS with binaural acoustic hearing affords benefit for subjective spatial hearing and sound quality beyond CI listening configurations using monaural acoustic hearing.

Sensitivity and Costs of Intraoperative Trans-Impedance Matrix Recordings, Spread of Excitation Functions, and X-ray Imaging in Detecting Cochlear Implant Tip Foldovers.

Evaluate the sensitivity and financial costs of Trans-Impedance Matrix recordings, Spread of Excitation functions, and x-rays in detecting cochlear implant tip foldovers. Tertiary academic medical center. 113 ears of 108 patients. Following cochlear implantation and before concluding surgery, intraoperative Trans-Impedance Matrix recordings, Spread of Excitation functions, and x-rays were conducted to evaluate presence of tip foldover. Presence of tip foldover; recording time necessary for and costs of Trans-Impedance Matrix, spread of excitation, and x-rays. There were six tip foldovers. Trans-Impedance Matrix showed 100% sensitivity, 100% specificity, 100% positive predictive value, and 100% negative predicative value in detecting tip foldovers. Spread of excitation showed 29% sensitivity, 99% specificity, 67% positive predictive value, and 95% negative predicative value. Trans-Impedance Matrix recordings were completed significantly faster than spread of excitation and x-rays. Elimination of x-rays from our intraoperative workflow results in a twofold cost reduction. Trans-Impedance Matrix recordings have potential great clinical utility in evaluating proper CI placement intraoperatively and reducing costs of surgery while not compromising patient care. Given the low tip foldover rate, a multicenter study is in progress to evaluate the sensitivity, specificity, positive predictive value, and negative predicative value of Trans-Impedance Matrix in a larger dataset. This can provide better guidance to cochlear implant clinics interested in evaluating the impact of using Trans-Impedance Matrix on patient care as well as the economics of reducing use of intraoperative imaging.

Comparing Cochlear Implant Outcomes in 100 Patients With Sporadic Vestibular Schwannoma Managed With Observation, Radiosurgery, or Microsurgery: A Multi-Institutional Review.

To compare cochlear implant (CI) speech perception outcomes in patients with sporadic vestibular schwannoma (VS) managed with observation, radiosurgery, or microsurgery. Retrospective review. Eleven tertiary academic medical centers. One hundred patients with sporadic VS who received an ipsilateral CI. Ipsilateral cochlear implantation. Pure-tone thresholds, monosyllabic speech perception testing scores, and rates of open-set speech acquisition. Of the 100 patients studied, 54 underwent microsurgery, 26 underwent radiosurgery, 19 continued observation, and 1 underwent multimodal therapy. Among all patients, the median post-implantation pure-tone average was 31 dB (interquartile range [IQR] 25-39 dB) and the median monosyllabic speech perception score was 30% (IQR 0-60%) at a median of 12 months (IQR 5-25 months) post-implantation. Patients who were managed with microsurgery (median speech perception score 11%, IQR 0-52%) exhibited poorer implant outcomes overall compared with those managed with observation (median speech perception score 52%, IQR 40-72%) or radiosurgery (median speech perception score 30%, IQR 16-60%). Open-set speech perception was achieved in 61% of patients managed with microsurgery, 100% with observation, and 80% with radiosurgery. In a multivariable setting, those managed with observation (p = 0.02) or who underwent radiosurgery (p = 0.04) were significantly more likely to achieve open-set speech perception compared with patients who underwent microsurgery. Cochlear implants offer benefit in selected patients with sporadic VS. Although achieved in over half of people after microsurgery, open-set speech perception is more reliably attained in patients who are treated with observation or radiosurgery compared with microsurgical resection. These data may inform patient counseling and VS tumor management in people who may benefit from implantation.

The Relationship Between eSRTs and Upper Stimulation Levels in a Large Cohort of Adult Cochlear Implant Recipients.

To compare electrically evoked stapedial reflex thresholds (eSRTs) measured at 1 month post-activation to upper stimulation levels used for programming adult cochlear implant (CI) recipients over time in a large clinical population. Review of prospectively collected clinical database. Large CI program at an academic medical center. Postlingually deafened adult CI recipients (n = 439). eSRTs recorded in the medical record and upper stimulation levels derived from the programming software at 1 and 6 months post-activation. The correlation between eSRTs and upper stimulation levels was strong for all three manufacturers (r = 0.80-0.86). On average, upper stimulation levels were set 15.4 clinical levels below eSRT for Cochlear using a pulse width of 25 microseconds, 13.4 clinical levels below eSRT for Cochlear using a pulse width of 37 microseconds, 11.3 clinical units below eSRT for Advanced Bionics, and 0.1 charge unit above eSRT for MED-EL. eSRTs were found to be elicited at similar levels for different electrodes/frequencies across the array. After upper stimulation levels were set based on eSRT at 1 month post-activation, there was no significant change in upper stimulation levels between 1 and 6 months post-activation. eSRTs and upper stimulation levels are highly correlated. Average differences between eSRTs and upper stimulation levels reported herein can be used to guide programming in the clinic. Further, when eSRTs are used to program upper stimulation levels, upper stimulation levels should be relatively similar across channels and stable over time.

Cochlear nerve visualization in Normal anatomy and inner ear malformations.

This study aimed to qualitatively evaluate the variations in nerve bundles between patients with normal anatomy and those with inner-ear anomalies. Magnetic resonance imaging (MRI) scans of the temporal bones of candidates for cochlear implants (CIs) enrolled at a tertiary center were retrospectively reviewed from the clinical database. The 3.0-Tesla MRI scans were analyzed using a three-dimensional slicer to visualize the nerve bundles in the internal auditory canal. A total of 49 ears were analyzed. Twenty ears exhibited normal inner ear anatomy, whereas 29 ears had various inner-ear malformations. The cochlear nerve (CN) was visible on all 20 scans with normal inner-ear anatomy. In addition, the CN was visualized in 18 scans with inner ear malformations. Furthermore, the CN was identified in six of the eight scans with IP type I, whereas in two scans, the CN and vestibular nerve were unclear. Three scans with a common cavity showed only two nerve bundles. The findings of this study show that the CN can be visualized in most inner-ear anatomical types. Even in severely malformed inner ears, the common nerve bundle that represents the cochlear and vestibular nerves can be visualized. The MRI is highly recommended for CN assessment before CI surgery. Level IV.

Barriers to Cochlear Implant Uptake in Adults: A Scoping Review.

Cochlear implants (CIs) provide access to sound and help mitigate the negative effects of hearing loss. As a field, we are successfully implanting more adults with greater amounts of residual hearing than ever before. Despite this, utilization remains low, which is thought to arise from barriers that are both intrinsic and extrinsic. A considerable body of literature has been published in the last 5 years on barriers to adult CI uptake, and understanding these barriers is critical to improving access and utilization. This scoping review aims to summarize the existing literature and provide a guide to understanding barriers to adult CI uptake. Inclusion criteria were limited to peer-reviewed articles involving adults, written in English, and accessible with a university library subscription. A cutoff of 20 years was used to limit the search. Barriers uncovered in this review were categorized into an ecological framework. The initial search revealed 2,315 items after duplicates were removed. One hundred thirty-one articles were reviewed under full-text, and 68 articles met the inclusion criteria. Race, ethnicity, and reimbursement are policy and structural barriers. Public awareness and education are societal barriers. Referral and geographical challenges are forms of organizational barriers. Living context and professional support are interpersonal barriers. At the individual level, sound quality, uncertainty of outcome, surgery, loss of residual hearing, and irreversibility are all barriers to CI uptake. By organizing barriers into an ecological framework, targeted interventions can be used to overcome such barriers.

The Memphis SOUND Project: The Development of a Community-Based Research Project to Address Hearing Health Disparities Among Black Adults Who Qualify for Cochlear Implants.

The objective of this article is to introduce the concept of community-based participatory research as a means to understand barriers to cochlear implant access racially minoritized populations. Black adults living in the United States experience unique barriers to cochlear implantation. Community-based research approaches can be used to understand and address these barriers. The Memphis SOUND Project is a community-based research initiative that seeks to address hearing health disparities by examining utilization of hearing healthcare among Black adults. Preliminary findings introduce motivators and barriers related to CI intervention in this population. This Memphis SOUND Project provides valuable insights to the benefits of community-based research in understanding and addressing CI utilization disparities.

Assessment of Electrically Evoked Stapedius Reflex Threshold (eSRT) for Auditory Mapping in Pulse Width Modulation Cochlear Implants: The Effect of Multielectrode Stimulation.

This study assesses the electrically evoked stapedius reflex threshold (eSRT) as an objective method for generating auditory maps in individuals with pulse-width-modulation cochlear implants (CIs). It investigates the impact of both single- and multiple-electrode stimulations on eSRT detection rates and their association with patients' comfort loudness levels (C-levels). Despite eSRT exploration by several CI brands incorporating pulse-amplitude-modulation stimulation technology, there is a lack of information on systems using pulse-width modulation. The eSRT was measured in 19 ears ipsilaterally and contralaterally in response to stimulations in groups of 1, 3, and 5 electrodes across five distinct cochlear regions, spanning from apical to basal. For each group, the eSRT detection rate and its correlation with the C-levels were analyzed both regionally and overall. In both contralateral and ipsilateral sides, higher electrically evoked stapedius reflex (eSR) detection rates were obtained for multielectrode (67%, 47%) than for single-electrode (41%, 23%) stimulation. Invoking eSR in the apical and basal regions was easier than in the middle region. The multiple stimulation just increased slightly the correlation coefficients between eSRT and C-levels from 0.73 to 0.77 and from 0.77 to 0.85 (p < 0.05) for the contralateral and ipsilateral ears, respectively. Our research indicates that using a multielectrode stimulation approach enhances the detection rate of eSRT and slightly improves the correlation coefficient between eSRT and C-levels. It is found preferable to obtain measurements from the contralateral side due to its higher detection rate, although the ipsilateral side yields a marginally higher correlation coefficient. The findings suggest that eSRTs obtained from pulse width modulation implants could aid audiologists in programming the device.

Estimating Cognitive Workload Using Task-Related Pupillary Responses in Simulated Drilling in Cochlear Implantation.

Training of temporal bone drilling requires more than mastering technical skills with the drill. Skills such as visual imagery, bimanual dexterity, and stress management need to be mastered along with precise knowledge of anatomy. In otorhinolaryngology, these psychomotor skills underlie performance in the drilling of the temporal bone for access to the inner ear in cochlear implant surgery. However, little is known about how psychomotor skills and workload management impact the practitioners' continuous and overall performance. To understand how the practitioner's workload and performance unfolds over time, we examine task-evoked pupillary responses (TEPR) of 22 medical students who performed transmastoid-posterior tympanotomy (TMPT) and removal of the bony overhang of the round window niche in a 3D-printed model of the temporal bone. We investigate how students' TEPR metrics (Average Pupil Size [APS], Index of Pupil Activity [IPA], and Low/High Index of Pupillary Activity [LHIPA]) and time spent in drilling phases correspond to the performance in key drilling phases. All TEPR measures revealed significant differences between key drilling phases that corresponded to the anticipated workload. Enlarging the facial recess lasted significantly longer than other phases. IPA captured significant increase of workload in thinning of the posterior canal wall, while APS revealed increased workload during the drilling of the bony overhang. Our findings contribute to the contemporary competency-based medical residency programs where objective and continuous monitoring of participants' progress allows to track progress in expertise acquisition. Laryngoscope, 134:5087-5095, 2024.

Early Hearing Outcomes and Audiological Experiences With a Novel Fully Implanted Cochlear Implant.

To review audiological experiences and early hearing outcomes from the early feasibility study of a fully implanted cochlear implant. Prospective cohort. Tertiary academic medical center. Three adults (two-male, one female) with bilateral sensorineural hearing loss. Implantation with a fully implanted cochlear implant as part of an early feasibility study. Postoperative unaided and aided pure-tone audiometry, tympanometry, mapping parameters, speech perception, battery life, and quality-of-life assessment. All patients in the early feasibility study of this fully implanted cochlear implant now use their devices regularly. Preoperative and postoperative audiometric measurements showed that their residual hearing in the implanted ear decreased slightly after surgery but was preserved. All patients had type A tympanograms after their transient middle ear effusion resolved. Electrical stimulation levels were comparable to those routinely used in traditional cochlear implants. Two of the three patients use a hearing aid in the implanted ear for additional gain and show significant improvement in speech perception since implantation. Average battery life before recharging is 4 days. All patients are regular users with two showing improvement in quality-of-life metrics after receiving the fully implanted cochlear implant. The patient experience and hearing outcomes from the early feasibility study of a novel fully implanted cochlear implant are detailed in this study and demonstrate ease of operation and daily use by all participants. All patients obtained hearing, but two of three use a hearing aid with their device to overcome unanticipated implant circuitry noise and achieve improved speech perception scores. Current work is focused on reducing this system noise to allow for the device to be used as intended, without a hearing aid.

Ensemble responses of auditory midbrain neurons in the cat to speech stimuli at different signal-to-noise ratios

Originally reserved for those who are profoundly deaf, cochlear implantation is now common for people with partial hearing loss, particularly when combined with a hearing aid. This combined intervention enhances speech comprehension and sound quality when compared to electrical stimulation alone, particularly in noisy environments, but the physiological basis for the benefits is not well understood. Our long-term aim is to elucidate the underlying physiological mechanisms of this improvement, and as a first step in this process, we have investigated in normal hearing cats, the degree to which the patterns of neural activity evoked in the inferior colliculus (IC) by speech sounds in various levels of noise allows discrimination between those sounds. Neuronal responses were recorded simultaneously from 32 sites across the tonotopic axis of the IC in anaesthetised normal hearing cats (n=7). Speech sounds were presented at 20, 40 and 60dB SPL in quiet and with increasing levels of additive noise (signal-to-noise ratios (SNRs) –20, –15, –10, –5, 0, +5, +10, +15, +20dB). Neural discrimination was assessed using a Euclidean measure of distance between neural responses, resulting in a function reflecting speech sound differentiation across various SNRs. Responses of IC neurons reliably encoded the speech stimuli when presented in quiet, with optimal performance when an analysis bin-width of 5-10ms was used. Discrimination thresholds did not depend on stimulus level and were best for shorter analysis binwidths. This study sheds light on how the auditory midbrain represents speech sounds and provides baseline data with which responses to electro-acoustic speech sounds in partially deafened animals can be compared.

Working Memory, Attention Skills, and Language Proficiency in Children with Unilateral and Bilateral Cochlear Implants.

Previous studies observed that children with cochlear implants (CIs) have poor language, working memory, and attention skills. The ability to perform cognitive tasks, such as attention and memory, plays a crucial role in the academic achievement and everyday life of children with hearing impairment. This study aimed to evaluate and compare the effects of age at the time of implantation and bilateral hearing on cognitive skills, such as language development, working memory, and selective attention, among children with CIs. Language skills were assessed using the Test of Language Development-Primary: Fourth Edition (TOLD-P:4), working memory using the Visual-Aural Digit Span Test-Revised Form (VADS-R), and selective attention skills using the Stroop Test TBAG Form. A total of 58 participants, comprised of 21 children with early unilateral CIs (before 2 years), 18 children with late unilateral CIs (after 2 years), and 19 children with bilateral CIs, between the ages of 6 and 9 years, were included in the study. According to the age at the time of implantation and whether or not the participant was unilaterally or bilaterally implanted, the mean scores, percentage values, and resultant scores of the participants were calculated using the Mann-Whitney U test. The number of repeated backward digit spans for the VADS-R test, completion times, number of errors and corrections for the Stroop test, raw scores, scaled scores corresponding to raw scores at the relevant age, descriptive terms for the TOLD-P:4 test, and within-group comparisons for all tests were examined. There were significant differences in language, working memory, and attention skills between individuals with early and late unilateral cochlear implantation, whereas there were no significant differences in many subtests between individuals with early unilateral and bilateral cochlear implantation. These findings demonstrate the importance of early cochlear implantation and bilateral hearing on the development of cognitive processes, such as language development, selective attention, and memory skills, which are important factors that may contribute to children's academic performance and overall success.

Quality of life improvement in Cochlear implant outpatients: a non-randomized clinical trial of an auditory music training program

Objective Research on Cochlear implant (CI) outcomes has been mainly focused on verbal communication, whereas music perception has been less extensively explored. This study evaluated a music rehabilitation program, based on the mobile phone app Meludia (Meludia, France) to improve quality of life (QoL) and verbal perception in CI patients. Design In this non-randomised clinical trial, the experimental group underwent 16 Meludia sessions, while controls did not receive any music-specific rehabilitation. Patient-reported outcome (PRO) measures, including the MUSQUAV questionnaire and NCIQ domains, were utilised alongside Matrix speech perception tests (which measure speech understanding in noise). Study sample Forty patients with CI were considered: experimental group (21 patients) and control group (19 patients). Results Significant improvements (p = 0.017, and p < 0.001) in music-related PRO (MUSQUAV), and general CI PRO measures (NCIQ), respectively, were found in the experimental group. No significant differences were found in Matrix speech perception tests post-rehabilitation. Overall, 57% of participants in the experimental group reported subjective improvements in music perception. Conclusions This study showed the potential of home-based music rehabilitation in enhancing QoL for CI patients, supporting the possibility of implementing specific musical training programs in audiological care. Larger, randomised, controlled trials are necessary for further characterisation of this topic.