Effects of pulse shape on pitch sensitivity of cochlear implant users.

Contemporary cochlear implants (CIs) use cathodic-leading symmetric biphasic (C-BP) pulses for electrical stimulation. It remains unclear whether asymmetric pulses emphasizing the anodic or cathodic phase may improve spectral and temporal coding with CIs. This study tested place- and temporal-pitch sensitivity with C-BP, anodic-centered triphasic (A-TP), and cathodic-centered triphasic (C-TP) pulse trains on apical, middle, and basal electrodes in 10 implanted ears. Virtual channel ranking (VCR) thresholds (for place-pitch sensitivity) were measured at both a low and a high pulse rate of 99 (Experiment 1) and 1000 (Experiment 2) pulses per second (pps), and amplitude modulation frequency ranking (AMFR) thresholds (for temporal-pitch sensitivity) were measured at a 1000-pps pulse rate in Experiment 3. All stimuli were presented in monopolar mode. Results of all experiments showed that detection thresholds, most comfortable levels (MCLs), VCR thresholds, and AMFR thresholds were higher on more basal electrodes. C-BP pulses had longer active phase duration and thus lower detection thresholds and MCLs than A-TP and C-TP pulses. Compared to C-TP pulses, A-TP pulses had lower detection thresholds at the 99-pps but not the 1000-pps pulse rate, and had lower MCLs at both pulse rates. A-TP pulses led to lower VCR thresholds than C-BP pulses, and in turn than C-TP pulses, at the 1000-pps pulse rate. However, pulse shape did not affect VCR thresholds at the 99-pps pulse rate (possibly due to the fixed temporal pitch) or AMFR thresholds at the 1000-pps pulse rate (where the overall high performance may have reduced the changes with different pulse shapes). Notably, stronger polarity effect on VCR thresholds (or more improvement in VCR with A-TP than with C-TP pulses) at the 1000-pps pulse rate was associated with stronger polarity effect on detection thresholds at the 99-pps pulse rate (consistent with more degeneration of auditory nerve peripheral processes). The results suggest that A-TP pulses may improve place-pitch sensitivity or spectral coding for CI users, especially in situations with peripheral process degeneration.

The role of lexical and prosodic characteristics of mothers' child-directed speech for the early vocabulary development of Italian children with cochlear implants.

BACKGROUND: Variability in the vocabulary outcomes of children with cochlear implants (CIs) is partially explained by child-directed speech (CDS) characteristics. Yet, relatively little is known about whether and how mothers adapt their lexical and prosodic characteristics to the child's hearing status (before and after implantation, and compared with groups with normal hearing (NH)) and how important they are in affecting vocabulary development in the first 12 months of hearing experience. AIMS: To investigate whether mothers of children with CIs produce CDS with similar lexical and prosodic characteristics compared with mothers of age-matched children with NH, and whether they modify these characteristics after implantation. In addition, to investigate whether mothers' CDS characteristics predict children's early vocabulary skills before and after implantation. METHODS & PROCEDURES: A total of 34 dyads (17 with NH, 17 with children with CIs; ages = 9-32 months), all acquiring Italian, were involved in the study. Mothers' and children's lexical quantity (tokens) and variety (types), mothers' prosodic characteristics (pitch range and variability), and children's vocabulary skills were assessed at two time points, corresponding to before and 1 year post-CI activation for children with CIs. Children's vocabulary skills were assessed using parent reports; lexical and prosodic characteristics were observed in semi-structured mother-child interactions. OUTCOMES & RESULTS: Results showed that mothers of children with CIs produced speech with similar lexical quantity but lower lexical variety, and with increased pitch range and variability, than mothers of children with NH. Mothers generally increased their lexical quantity and variety and their pitch range between sessions. Children with CIs showed reduced expressive vocabulary and lower lexical quantity and variety than their peers 12 months post-CI activation. Mothers' prosodic characteristics did not explain variance in children's vocabulary skills; their lexical characteristics predicted children's early vocabulary and lexical outcomes, especially in the NH group, but were not related to later language development. CONCLUSIONS & IMPLICATIONS: Our findings confirm previous studies on other languages and support the idea that the lexical characteristics of mothers' CDS have a positive effect on children's early measures of vocabulary development across hearing groups, whereas prosodic cues play a minor role. Greater input quantity and quality may assist children in the building of basic language model representations, whereas pitch cues may mainly serve attentional and emotional processes. Results emphasize the need for additional longitudinal studies investigating the input received from other figures surrounding the child and its role for children's language development. WHAT THIS PAPER ADDS: What is already known on the subject Mothers' CDS is thought to facilitate and support language acquisition in children with various language developmental trajectories, including children with CIs. Because children with CIs are at risk for language delays and have acoustic processing limitations, their mothers may have to produce a lexically simpler but prosodically richer input, compared to mothers of children with NH. Yet, the literature reports mixed findings and no study to our knowledge has concurrently addressed the role of mothers' lexical and prosodic characteristics for children's vocabulary development before implantation and in the first 12 months of hearing experience. What this study adds to the existing knowledge The study shows that mothers of children with CIs produce input of similar quantity but reduced variety, and with heightened pitch characteristics, compared to mothers of children with NH. There was also a general increase in mothers' lexical quantity and variety, and in their pitch range, between sessions. Only their lexical characteristics predicted children's early vocabulary skills. Their lexical variety predicted children's expressive vocabulary and lexical variety only in the NH group. What are the practical and clinical implications of this work? These findings expand our knowledge about the effects of maternal input and may contribute to the improvement of early family-centred intervention programmes for supporting language development in children with CIs.

Automatic localization of cochlear implant electrodes using cone beam computed tomography images.

BACKGROUND: Cochlear implants (CI) are implantable medical devices that enable the perception of sounds and the understanding of speech by electrically stimulating the auditory nerve in case of inner ear damage. The stimulation takes place via an array of electrodes surgically inserted in the cochlea. After CI implantation, cone beam computed tomography (CBCT) is used to evaluate the position of the electrodes. Moreover, CBCT is used in research studies to investigate the relationship between the position of the electrodes and the hearing outcome of CI user. In clinical routine, the estimation of the position of the CI electrodes is done manually, which is very time-consuming. RESULTS: The aim of this study was to optimize procedures of automatic electrode localization from CBCT data following CI implantation. For this, we analyzed the performance of automatic electrode localization for 150 CBCT data sets of 10 different types of electrode arrays. Our own implementation of the method by Noble and Dawant (Lecture notes in computer science (Including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics), Springer, pp 152-159, 2015. https://doi.org/10.1007/978-3-319-24571-3_19 ) for automated electrode localization served as a benchmark for evaluation. Differences in the detection rate and the localization accuracy across types of electrode arrays were evaluated and errors were classified. Based on this analysis, we developed a strategy to optimize procedures of automatic electrode localization. It was shown that particularly distantly spaced electrodes in combination with a deep insertion can lead to apical-basal confusions in the localization procedure. This confusion prevents electrodes from being detected or assigned correctly, leading to a deterioration in localization accuracy. CONCLUSIONS: We propose an extended cost function for automatic electrode localization methods that prevents double detection of electrodes to avoid apical-basal confusions. This significantly increased the detection rate by 11.15 percent points and improved the overall localization accuracy by 0.53 mm (1.75 voxels). In comparison to other methods, our proposed cost function does not require any prior knowledge about the individual cochlea anatomy.

Patient-Led Research to Develop a Training Programme for Restoring Musical Joy in Cochlear Implant Recipients: A Reflexive Process Evaluation.

BACKGROUND: The role of patients in healthcare research is slowly evolving, although patient roles in the research process are limited. This paper reports on a patient-led research project aiming to develop a musical hearing training programme for patients with a cochlear implant (CI): the Musi-CI programme. A CI is an inner ear prosthesis that allows people with severe hearing loss to hear. However, while speech can be understood, CI users cannot fully enjoy music or feel aversion to it. The Musi-CI programme aims to reduce this music aversion to ultimately improve music enjoyment and social participation. The development of the Musi-CI programme was supported by a consortium of professionals in CI rehabilitation and research. The aim of this paper is to describe and evaluate the Musi-CI programme development process and its impact on professional CI rehabilitation and research. METHODS: Programme development was described using a 3-layered process model of action research, distinguishing the CI user process, the healthcare professional process and the research process. To evaluate perceptions on the programme development process, consortium partners provided written comments and participated in a reflexive evaluation session that was video-recorded. Reflexive evaluation aims for collective learning and strengthening collaboration among participants. Written comments and video data were analysed using template analysis. RESULTS: The involvement of an expert by experience was perceived as challenging but rewarding for all consortium partners, opening up new perspectives on CI-rehabilitation practice and research. Data analysis revealed two themes on the programme development process, professional space and acknowledgement, and two themes on the outcomes on CI rehabilitation and research: critical reflection and paradigm shift. CONCLUSION: Experts by experience represent a different knowledge domain that may contribute to change in rehabilitation and research. PATIENT OR PUBLIC CONTRIBUTION: The development of the programme was initiated by a professional musician and CI user who organized the funding, had a leading role throughout the research process, including the write-up of the results, and co-authored this paper.

Metabolic Profiling of Cochlear Organoids Identifies α-Ketoglutarate and NAD+ as Limiting Factors for Hair Cell Reprogramming.

Cochlear hair cells are the sensory cells responsible for transduction of acoustic signals. In mammals, damaged hair cells do not regenerate, resulting in permanent hearing loss. Reprogramming of the surrounding supporting cells to functional hair cells represent a novel strategy to hearing restoration. However, cellular processes governing the efficient and functional hair cell reprogramming are not completely understood. Employing the mouse cochlear organoid system, detailed metabolomic characterizations of the expanding and differentiating organoids are performed. It is found that hair cell differentiation is associated with increased mitochondrial electron transport chain (ETC) activity and reactive oxidative species generation. Transcriptome and metabolome analyses indicate reduced expression of oxidoreductases and tricyclic acid (TCA) cycle metabolites. The metabolic decoupling between ETC and TCA cycle limits the availability of the key metabolic cofactors, α-ketoglutarate (α-KG) and nicotinamide adenine dinucleotide (NAD+). Reduced expression of NAD+ in cochlear supporting cells by PGC1α deficiency further impairs hair cell reprogramming, while supplementation of α-KG and NAD+ promotes hair cell reprogramming both in vitro and in vivo. These findings reveal metabolic rewiring as a central cellular process during hair cell differentiation, and highlight the insufficiency of key metabolites as a metabolic barrier for efficient hair cell reprogramming.

Interaction of sensory processing and balance in adult cochlear implant users.

PUROPSE: The aim of this study was to evaluate the sensory processing skills, quality of life and balance performance in adult cochlear implant users. METHODS: A sample of 40 individuals was studied in two groups; 20 normal hearing individuals (37.84 ± 15.39 years old) and 20 cochlear implant users (35.58 ± 11.22 year old). Balance performance was assessed by Computerized Dynamic Posturography. The Adolescent/Adult Sensory Profile completed by the individual was used to assess sensory processing skills. Finally, quality of life was assessed with the Short Form-36. RESULTS: Among the different sensory processing parameters in the adolescent/adult sensory profile, a significant difference was found between the two groups in the parameters of low registration, sensory sensitivity and sensory avoidance (p < .05). Visual, vestibular and composite scores were found to be lower in cochlear implant users by Computerised Dynamic Posturography assessment (p < .05). When assessing quality of life, emotional well-being and social functioning parameters were found to be lower in cochlear implant users (p < .05). CONCLUSION: Factors such as the inability to reach sufficient auditory stimuli due to hearing loss and the occurrence of vestibular problems after cochlear implant surgery limit the quantity and quality of sensory stimuli from the environment. Individuals with cochlear implants may prefer to live isolated from society because they cannot adequately process incoming sensory stimuli due to hearing/balance problems, and this may negatively affect the quality of life of individuals. Our findings revealed the necessity of multisensory assessment and therapy protocols when rehabilitating individuals with cochlear implants.

The German cochlear implant registry: one year experience and first results on demographic data.

PURPOSE: Clinical registries have great potential for quality control of medical procedures regarding the indications, therapeutic processes and results, including their possible complications. This is particularly true when providing patients with severe hearing loss or deafness with a cochlear implant (CI). This treatment represents a lifelong care process that requires continuous quality control over time. On the initiative of the Executive Committee of the German Society of Otorhinolaryngology (Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V., DGHNO-KHC), a national German CI registry (Deutsches Cochlear Implant Register, DCIR) was established in January 2022. This article focuses on the first demographic and baseline data of the DCIR. METHODS: The DCIR covers the complete therapeutic process from indication, surgery, fitting and lifelong aftercare in CI therapy. By the end of 2022, 75 hospitals in Germany had agreed to contribute to the DCIR. RESULTS: During the year 2022, 63 hospitals actively contributed data to the DCIR. Pseudonymized data from 2,292 CI implantations (2,176 primary implantations, 99 explantations with immediate re-implantations and 17 re-implantations following an earlier explantation) in 2,108 patients were documented. Cochlear implantation was accomplished in 1,807 adults (≥ 18 years) and 301 children (< 18 years). Fourty patients (1,9%) were children < 1 year of age and 55 (2,6%) were patients > 85 years. From the total of 2,292 implantations, 226 (9.9%) were performed as simultaneous bilateral implantations (CI implantation in both ears of 113 patients on the same day of surgery) and 412 implantations (19.1% of 2,162 implantations with data provided on the contralateral ear's hearing status) were in patients with single sided deafness (normal hearing in the contralateral ear). In addition, the reported complications in 2022 were also evaluated. Seven reports (0.4%) of mild to moderate severe facial nerve dysfunctions were documented. No reports of severe or total facial nerve dysfunction (House-Brackmann grade V/VI), meningitis or death related to CI therapy were documented. CONCLUSION: Although still in the start-up phase, these initial DCIR data already provide an interesting first insight into the demographic structure and baseline data of CI therapy in Germany. The successful implementation of the DCIR represents an important step towards continuous quality control of CI care.

Trends in research on cochlear implantation with inner ear malformation: a bibliometric and visualization analysis from 1986 to 2024.

OBJECTIVE: The aim of this study was to conduct a bibliometric and visualization analysis of research on cochlear implantation (CI) for inner ear malformations (IEMs) from 1986 to 2024. METHODS: A comprehensive literature search was performed using the Web of Science Core Collection Database, resulting in the identification of 431 relevant publications. Various data analysis and visualization tools, including VOSviewer, CiteSpace, and Bibliometrix, were utilized to analyze annual publication outputs, countries/regions and institutions, authors, journals and studies, keywords, and theme evolution. RESULTS: The study revealed an overall increasing trend in research output on CI for IEMs, with significant contributions from countries such as the United States, China, Turkey, Germany, and Italy. The analysis also identified key authors, research teams, journals, and studies that have made substantial contributions to the field. Furthermore, the study highlighted important research hotspots and trends, such as the classification of IEMs, outcomes of CI for IEMs, and the management of pediatric patients with IEMs. CONCLUSION: The findings of this study provide a comprehensive overview of the research landscape surrounding CI for IEMs. The results serve as a basis for future research topic selection and emphasize the need for enhanced international collaboration and the publication of high-impact research to further advance this field.

Diving technique of cochlear implant electrode insertion for hearing preservation: how I do it.

BACKGROUND: Preservation of intracochlear structures and residual hearing has become a major concern in modern cochlear implant. Consequently, many efforts have been made to minimize intraoperative trauma, especially while cochlear fenestration and electrode insertion. METHODS: Building on the core concept of "soft surgery", a modified approach, described as diving technique for cochlear implant electrode array insertion is proposed. Steps and technical points are presented with figures, video and review of relevant anatomy. CONCLUSIONS: This novel diving technique is operationally feasible and safe, promising to minimize intraoperative invasion and thus preserve residual hearing in cochlear implant.

Lexical tone recognition in multi-talker babbles and steady-state noise by Mandarin-speaking children with unilateral cochlear implants or bimodal hearing.

BACKGROUND AND OBJECTIVES: Lexical tone presents challenges to cochlear implant (CI) users especially in noise conditions. Bimodal hearing utilizes residual acoustic hearing in the contralateral side and may offer benefits for tone recognition in noise. The purpose of the present study was to evaluate tone recognition in both steady-state noise and multi-talker babbles by the prelingually-deafened, Mandarin-speaking children with unilateral CIs or bimodal hearing. METHODS: Fifty-three prelingually-deafened, Mandarin-speaking children who received CIs participated in this study. Twenty-two of them were unilateral CI users and 31 wore a hearing aid (HA) in the contralateral ear (i.e., bimodal hearing). All subjects were tested for Mandarin tone recognition in quiet and in two types of maskers: speech-spectrum-shaped noise (SSN) and two-talker babbles (TTB) at four signal-to-noise ratios (-6, 0, +6, and +12 dB). RESULTS: While no differences existed in tone recognition in quiet between the two groups, the Bimodal group outperformed the Unilateral CI group under noise conditions. The differences between the two groups were significant at SNRs of 0, +6, and +12 dB in the SSN conditions (all p < 0.05), and at SNRs of +6 and +12 dB of TTB conditions (both p < 0.01), but not significant at other conditions (p > 0.05). The TTB exerted a greater masking effect than the SSN for tone recognition in the Unilateral CI group as well as in the Bimodal group at all SNRs tested (all p < 0.05). Among demographic or audiometric variables, only age at implantation showed a weak but significant correlation with the mean tone recognition performance under the SSN conditions (r = -0.276, p = 0.045). However, when Bonferroni correction was applied to the correlation analysis results, the weak correlation became not significant. CONCLUSION: Prelingually-deafened children with CIs face challenges in tone perception in noisy environments, especially when the noise is fluctuating in amplitude such as the multi-talker babbles. Wearing a HA on the contralateral side when residual hearing permits is beneficial for tone recognition in noise.

Contribution of Temporal Fine Structure Cues to Concurrent Vowel Identification and Perception of Zebra Speech.

Introduction The limited access to temporal fine structure (TFS) cues is a reason for reduced speech-in-noise recognition in cochlear implant (CI) users. The CI signal processing schemes like electroacoustic stimulation (EAS) and fine structure processing (FSP) encode TFS in the low frequency whereas theoretical strategies such as frequency amplitude modulation encoder (FAME) encode TFS in all the bands. Objective The present study compared the effect of simulated CI signal processing schemes that either encode no TFS, TFS information in all bands, or TFS only in low-frequency bands on concurrent vowel identification (CVI) and Zebra speech perception (ZSP). Methods Temporal fine structure information was systematically manipulated using a 30-band sine-wave (SV) vocoder. The TFS was either absent (SV) or presented in all the bands as frequency modulations simulating the FAME algorithm or only in bands below 525 Hz to simulate EAS. Concurrent vowel identification and ZSP were measured under each condition in 15 adults with normal hearing. Results The CVI scores did not differ between the 3 schemes (F (2, 28) = 0.62, p = 0.55, η 2 p = 0.04). The effect of encoding TFS was observed for ZSP (F (2, 28) = 5.73, p = 0.008, η 2 p = 0.29). Perception of Zebra speech was significantly better with EAS and FAME than with SV. There was no significant difference in ZSP scores obtained with EAS and FAME ( p = 1.00) Conclusion For ZSP, the TFS cues from FAME and EAS resulted in equivalent improvements in performance compared to the SV scheme. The presence or absence of TFS did not affect the CVI scores.

Functional Language in Children from a Public Cochlear Implant Program in a Developing Country.

Introduction The World Health Organization (WHO) estimates that ∼ 32 million children worldwide are affected by hearing loss (HL). Cochlear implant is the first-line treatment for severe to profound sensorineural HL. It is considered one of the most successful prostheses developed to date. Objective To evaluate the oral language development of pediatric patients with prelingual deafness implanted in a reference hospital for the treatment of HL in southern Brazil. Methods We conducted a retrospective cohort study with a review of medical records of patients undergoing cochlear implant surgery between January 2009 and December 2018. Language development was assessed by reviewing consultations with speech therapy professionals from the cochlear implant group. Results A total of 152 children were included in the study. The mean age at cochlear implant surgery was of 41 months (standard deviation [SD]: ± 15). The patients were divided into six groups considering the type of language most used in their daily lives. We found that 36% of children use oral language as their primary form of communication. In a subanalysis, we observed that patients with developed or developing oral language had undergone cochlear implant surgery earlier than patients using Brazilian Sign Language (Língua Brasileira de Sinais, LIBRAS, in Portuguese) or those without developed language. Conclusion The cochlear implant is a state-of-the-art technology that enables the re-establishment of the sense of hearing and the development of oral language. However, language development is a complex process known to present a critical period to properly occur. We still see many patients receiving late diagnosis and treatment, which implies a delay and, often, the impossibility of developing oral communication. Level of Evidence Level 3 (cohort study).

Age-related alterations in efferent medial olivocochlear-outer hair cell and primary auditory ribbon synapses in CBA/J mice.

Introduction: Hearing decline stands as the most prevalent single sensory deficit associated with the aging process. Giving compelling evidence suggesting a protective effect associated with the efferent auditory system, the goal of our study was to characterize the age-related changes in the number of efferent medial olivocochlear (MOC) synapses regulating outer hair cell (OHC) activity compared with the number of afferent inner hair cell ribbon synapses in CBA/J mice over their lifespan. Methods: Organs of Corti of 3-month-old CBA/J mice were compared with mice aged between 10 and 20 months, grouped at 2-month intervals. For each animal, one ear was used to characterize the synapses between the efferent MOC fibers and the outer hair cells (OHCs), while the contralateral ear was used to analyze the ribbon synapses between inner hair cells (IHCs) and type I afferent nerve fibers of spiral ganglion neurons (SGNs). Each cochlea was separated in apical, middle, and basal turns, respectively. Results: The first significant age-related decline in afferent IHC-SGN ribbon synapses was observed in the basal cochlear turn at 14 months, the middle turn at 16 months, and the apical turn at 18 months of age. In contrast, efferent MOC-OHC synapses in CBA/J mice exhibited a less pronounced loss due to aging which only became significant in the basal and middle turns of the cochlea by 20 months of age. Discussion: This study illustrates an age-related reduction on efferent MOC innervation of OHCs in CBA/J mice starting at 20 months of age. Our findings indicate that the morphological decline of efferent MOC-OHC synapses due to aging occurs notably later than the decline observed in afferent IHC-SGN ribbon synapses.

Duration of cochlear implant use in children with prelingual single-sided deafness is a predictor of word perception in the CI ear.

As part of a longitudinal study regarding the benefit of early cochlear implantation for children with single-sided deafness, the current work explored the children's daily device use, potential barriers to full-time device use, and the children's ability to understand speech with the cochlear implant (CI). Data were collected from 20 children with prelingual SSD who received a CI before the age of 2.5 years, from the initial activation of the sound processor until the children were 4.8 to 11.0 years old. Daily device use was extracted from the CI's data logging, while word perception in quiet was assessed using direct audio input to the children's sound processor. The children's caregivers completed a questionnaire about habits, motivations, and barriers to device use. The children with SSD and a CI used their device on average 8.3 h per day, corresponding to 63 % of their time spent awake. All children except one could understand speech through the CI, with an average score of 59 % on a closed-set test and 73 % on an open-set test. More device use was associated with higher speech perception scores. Parents were happy with their decision to pursue a CI for their child. Certain habits, like taking off the sound processor during illness, were associated with lower device use. Providing timely counselling to the children's parents, focused on SSD-specific challenges, may be helpful to improve daily device use in these children.

Cochlear implantation in patients with inner ear schwannomas: a systematic review and meta-analysis of audiological outcomes.

PURPOSE: In patients with inner ear schwannomas (IES), reports on hearing rehabilitation with cochlear implants (CI) have increased over the past decade, most of which are case reports or small case series. The aim of this study is to systematically review the reported hearing results with CI in patients with IES considering the different audiologic outcome measures used in different countries. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, a search of published literature was conducted. We included patients with IES (primary or with secondary extension from the internal auditory canal (IAC) to the inner ear, sporadic or NF2 related) undergoing cochlear implantation with or without tumour removal. The audiological results were divided into the categories "monosyllables", "disyllables", "multisyllabic words or numbers", and "sentences". RESULTS: Predefined audiological outcome measures were available from 110 patients and 111 ears in 27 reports. The mean recognition scores for monosyllabic words with CI were 55% (SD: 24), for bisyllabic words 61% (SD: 36), for multisyllabic words and numbers 87% (SD: 25), and 71% (SD: 30) for sentences. Results from for multisyllabic words and numbers in general showed a tendency towards a ceiling effect. Possible risk factors for performance below average were higher complexity tumours (inner ear plus IAC/CPA), NF2, CI without tumour removal ("CI through tumour"), and sequential cochlear implantation after tumour removal (staged surgery). CONCLUSION: Hearing loss in patients with inner ear schwannomas can be successfully rehabilitated with CI with above average speech performance in most cases. Cochlear implantation thus represents a valuable option for hearing rehabilitation also in patients with IES while at the same time maintaining the possibility of MRI follow-up. Further studies should investigate possible risk factors for poor performance. Audiological tests and outcome parameters should be reported in detail and ideally be harmonized to allow better comparison between languages.

Outcomes of Aural Rehabilitation Provided in Person or by Telehealth Among Deaf/Hard of Hearing Young Children with Cochlear Implants or Hearing Aids.

Background: Cochlear implants and hearing aids may facilitate the development of listening and spoken language (LSL) in deaf/hard of hearing young children, but they require aural rehabilitation therapy-often unavailable outside urban areas-for optimal outcomes. This trial assessed the relative effectiveness of LSL therapy delivered either in person or by interactive video. The hypothesis was that telehealth service delivery would be noninferior to in-person therapy. Methods: Most parents refused randomization of their children to telehealth or in-person conditions; therefore, randomization was impossible. In consultation with the funder (NIDCD), the study design was modified. Parents were allowed to select their preferred study condition, and the study team was blinded to group membership. Forty-two families were in the in-person group and 35 in telehealth (40 and 30, respectively, after attrition). Primary endpoints were total score, auditory comprehension, and expressive communication on the Preschool Language Scale, 5th edition. There were several secondary speech, hearing, and language outcome measures. Assessments occurred at baseline and at follow-up after 6 months of LSL therapy. Results: Propensity scores were used to create two matched groups. At baseline, groups did not differ on PLS-5 scores. Change from baseline to F/U on age-equivalents for all three scores was nearly identical for both groups, although the telehealth group was younger, on average, than the in-person group. Discussion: Telehealth was noninferior to in-person services for all primary endpoints. For secondary outcomes, neither group demonstrated a significant advantage. Magnitudes of estimated group differences were small, suggesting nonsignificant differences not predominantly because of sample size. The telehealth group showed greater improvement on 15/24 of secondary language outcome measures. The findings provide evidence that telehealth is equivalent to in-person care for providing LSL therapy to young children with cochlear implants and hearing aids.

Utilization of SmartNav technology in cochlear implantation: optimizing efficiency in assessment of electrode placement.

OBJECTIVES: Proper electrode placement is essential for favorable hearing outcomes following cochlear implantation. Though often used, traditional intraoperative X-ray imaging is time consuming, exposes patients and staff to radiation, and poses interpretational challenges. The Nucleus® SmartNav System, utilizes electrode voltage telemetry (EVT) to analyze the positioning of the electrode array intraoperatively. This study investigates the efficacy of SmartNav in optimizing the efficiency and accuracy of assessing electrode placement. METHODS: This prospective clinical study analyzed placement of 50 consecutive Cochlear Corporation cochlear implants conducted at a single institution between March of 2022 and June of 2023. Placement check of electrode array using SmartNav and X-ray was completed and individually assessed. A comparative analysis of SmartNav and X-ray completion times for electrode placement assessment was conducted. RESULTS: Subjects included nine ears with abnormal anatomy and three reimplants. SmartNav placement check required a total time of 2.12 min compared to X-ray imaging at 14.23 min (p = 1.6E-16, CI 95%). Both SmartNav and X-ray had excellent sensitivity of 100% in identifying appropriate electrode position (p = 1.0). Tip fold-over was identified using both modalities in 3 cases with noted easier interpretation using SmartNav. CONCLUSION: The Nucleus® SmartNav System significantly outperformed traditional X-ray imaging, offering a faster and more straightforward approach to assessing electrode positioning during cochlear implant surgery, thereby enhancing surgical efficiency and patient safety.

Low-intensity noise exposure takes an essential part in the mechanism of late-onset hereditary hearing loss caused by Abcc1 mutation.

With the development of the social economy, we are exposed to increasing noise in our daily lives. Our previous work found an ABCC1(NM_004996.3:c.A1769G, NP_004987.2:p.N590S) variant which cosegregated with the patients in an autosomal dominant non-syndromic hearing loss family. At present, the specific mechanism of deafness caused by ABCC1 mutation is still not clear. Using the knock-in mouse model simulating human ABCC1 mutation, we found that the occurrence of family-related phenotypes was likely attributed to the combination of the mouse genotype and low-intensity noise. GSH and GSSG are important physiological substrates of ABCC1. The destruction of GSH-GSSG balance in the cochleae of both Abcc1N591S/+ mice and Abcc1N591S/N591S mice during low-intensity noise exposure may result in irreversible damage to the hair cells of the cochleae, consequently leading to hearing loss in mice. The findings offered a potential novel idea for the prevention and management of hereditary hearing loss within this family.

Human Olivocochlear Effects: A Statistical Detection Approach Applied to the Cochlear Microphonic Evoked by Swept Tones.

The human medial olivocochlear (MOC) reflex was assessed by observing the effects of contralateral acoustic stimulation (CAS) on the cochlear microphonic (CM) across a range of probe frequencies. A frequency-swept probe tone (125-4757 Hz, 90 dB SPL) was presented in two directions (up sweep and down sweep) to normal-hearing young adults. This study assessed MOC effects on the CM in individual participants using a statistical approach that calculated minimum detectable changes in magnitude and phase based on CM signal-to-noise ratio (SNR). Significant increases in CM magnitude, typically 1-2 dB in size, were observed for most participants from 354 to 1414 Hz, where the size and consistency of these effects depended on participant, probe frequency, sweep direction, and SNR. CAS-related phase lags were also observed, consistent with CM-based MOC studies in laboratory animals. Observed effects on CM magnitude and phase were in the opposite directions of reported effects on otoacoustic emissions (OAEs). OAEs are sensitive to changes in the motility of outer hair cells located near the peak region of the traveling wave, while the effects of CAS on the CM likely originate from MOC-related changes in the conductance of outer hair cells located in the basal tail of the traveling wave. Thus, MOC effects on the CM are complementary to those observed for OAEs.

Auditory brainstem response to paired clicks as a candidate marker of cochlear synaptopathy in humans.

OBJECTIVE: This study aimed to evaluate whether auditory brainstem response (ABR) using a paired-click stimulation paradigm could serve as a tool for detecting cochlear synaptopathy (CS). METHODS: The ABRs to single-clicks and paired-clicks with various inter-click intervals (ICIs) and scores for word intelligibility in degraded listening conditions were obtained from 57 adults with normal hearing. The wave I peak amplitude and root mean square values for the post-wave I response within a range delayed from the wave I peak (referred to as the RMSpost-w1) were calculated for the single- and second-click responses. RESULTS: The wave I peak amplitudes did not correlate with age except for the second-click responses at an ICI of 7 ms, and the word intelligibility scores. However, we found that the RMSpost-w1 values for the second-click responses significantly decreased with increasing age. Moreover, the RMSpost-w1 values for the second-click responses at an ICI of 5 ms correlated significantly with the scores for word intelligibility in degraded listening conditions. CONCLUSIONS: The magnitude of the post-wave I response for the second-click response could serve as a tool for detecting CS in humans. SIGNIFICANCE: Our findings shed new light on the analytical methods of ABR for quantifying CS.