Search Results (247)

Background/Objectives: Functional near-infrared spectroscopy (fNIRS) has emerged as a non-invasive, implant-compatible imaging modality capable of capturing cortical hemodynamics during ecologically valid auditory and linguistic tasks. Its silent operation and tolerance to electrical artifacts make it particularly well suited to the study of hearing-impaired individuals, including cochlear implant (CI) users. However, evidence on the application of fNIRS to investigate speech perception, cognitive performance, and proxy of cortical activation patterns in patients with hearing loss (HL) remains fragmented. This systematic review aims to provide a structured, population-stratified description of current fNIRS literature on auditory and cognitive processing in adults with age-related hearing loss (ARHL) and CI users. Methods: A systematic search on PubMed Central, Web of Science and Scopus, based on PRISMA (2020) guidelines, was conducted to identify original studies that evaluate speech perception by means of fNIRS to assess auditory and cognitive process in hearing-impaired populations. Results: Across studies, fNIRS consistently detected activation of superior temporal and frontal cortices during speech-related tasks. In ARHL, increased dorsolateral prefrontal cortex (DLPFC) recruitment during speech-in-noise indicated compensatory yet inefficient processing. Longitudinal auditory training led to reduced prefrontal overactivation and enhanced temporal–frontal connectivity. In CI users, cortical responses to phonological and comprehension tasks show partially overlapping activation patterns with normal hearing (NH) peers, although arising within different neurobiological contexts, and are modulated by device experience and residual hearing (AV) speech, and stimulus-level effects further shape cortical responses. When interpreted in light of developmental evidence, these findings may be contextualized as reflecting distinct trajectories of cortical reorganization, rather than a common mechanism. Conclusions: fNIRS provides a tool to investigate auditory and cognitive responses in distinct hearing-impaired populations under ecologically valid conditions. It detects maladaptive frontal inefficiency in ARHL, tracks neuroplastic changes after rehabilitation, and captures population-specific cortical recruitment patterns in CI users. These findings are descriptive and context-dependent, and do not support cross-population mechanistic generalizations. Standardized protocols and longitudinal pediatric studies are needed to clarify the potential clinical relevance of fNIRS-derived cortical measures. Full article

Millions of persons worldwide experience varying degrees of hearing loss, traditionally addressed through prosthetic solutions such as hearing aids and cochlear implants. However, a significant proportion of individuals cannot benefit from these technologies, cannot access them, or choose not to use them. In this context, non-prosthetic assistive technologies have emerged as a complementary paradigm, leveraging advances in sensing, artificial intelligence, and wearable computing to transform acoustic information into alternative perceptual representations rather than restoring auditory function. This survey provides a review of such systems, focusing on technologies that enhance environmental awareness, communication, and social interaction. Existing approaches are categorized along two main dimensions: the tasks they perform and the platforms on which they operate. Task-oriented analysis includes sound recognition (speech and non-speech), sound source localization, emotion recognition, sign language recognition, and related emerging functionalities. Platform-based analysis emphasizes wearable devices and mobile solutions enabling real-time and context-aware assistance. The survey further highlights key research trends, including real-time auditory scene analysis, portable processing, and artificial intelligence. It shows that recent studies increasingly demonstrate that combining auditory, visual, and haptic modalities improves robustness and usability in real-world conditions, particularly in noisy and dynamic environments. Finally, open challenges such as energy efficiency, latency, evaluation methodologies, and user acceptance are discussed. By synthesizing existing work and identifying open research directions, this survey aims to provide a structured foundation for future developments in intelligent, non-prosthetic assistive systems that redefine how auditory information is accessed and interpreted. Full article

Introduction: The present study aimed to compare cortical auditory maturation, as reflected by P1 latency of cortical auditory evoked potentials (CAEPs), in children with congenital severe-to-profound sensorineural hearing loss rehabilitated with unilateral cochlear implants (CIs) or bilateral conventional hearing aids (HAs). Materials and Methods: Eighty-five children with congenital severe-to-profound sensorineural hearing loss were included in this retrospective comparative study. Participants were divided into two groups: unilateral CI users (n = 42) and bilateral HA users (n = 43). All children were fitted with their devices before 48 months of age and achieved aided free-field thresholds between 30 and 50 dB HL. CAEPs were recorded using the Fonix^® HEARLab System with speech stimuli (/m/, /g/, /t/) presented at 55 dB SPL. P1 latency values were measured and compared between groups using independent samples t-tests. Correlation analyses were performed to assess the relationship between duration of device use and P1 latency. Results: Eighty-five children were included (CI: n = 42; HA: n = 43). Mean P1 latency values did not differ significantly between groups for the /m/ stimulus (126.4 ± 29.13 ms vs. 126.4 ± 29.28 ms, p = 1.00), /g/ stimulus (106.5 ± 26.46 ms vs. 110.1 ± 29.49 ms, p = 0.55), or /t/ stimulus (114.7 ± 22.93 ms vs. 118.5 ± 27.19 ms, p = 0.48). Age at device fitting was comparable between groups (27.95 ± 9.10 vs. 26.88 ± 14.15 months, p = 0.68). The duration of device use was significantly longer in the HA group (48.02 ± 28.39 months) compared to the CI group (26.00 ± 15.92 months) (p < 0.001). Correlation analysis revealed no significant association between duration of device use and P1 latency for any stimulus (/m/: p = 0.28; /g/: p = 0.17; /t/: p = 0.09). Conclusions: When devices were fitted before 48 months of age and aided thresholds were optimized, unilateral cochlear implantation and bilateral conventional hearing aids showed comparable P1 latency values as an index of cortical auditory maturation. These findings suggest that early and adequate auditory stimulation may play an important role in supporting cortical auditory development in children with congenital hearing loss, although results should be interpreted within the context of individualized clinical management. Full article

Background: Age-related hearing loss (ARHL) is the most common sensory disorder in older adults and has been identified as a potentially modifiable risk factor for cognitive decline and dementia. Increasing evidence suggests that auditory dysfunction may contribute to adverse cognitive trajectories through multiple interacting pathways. This narrative review examines the mechanisms underlying the association between ARHL and cognitive decline, evaluates the impact of hearing rehabilitation, and discusses future research priorities. Methods: A narrative synthesis of epidemiological, neurobiological, and interventional studies was conducted, with emphasis on longitudinal cohort studies, neuroimaging research, and clinical investigations of hearing aids (HAs) and cochlear implants (CIs). Results: ARHL is consistently associated with accelerated cognitive decline and increased dementia risk. Proposed mechanisms include sensory deprivation-related cortical reorganization, increased cognitive load during effortful listening, shared neuropathological processes, and social disengagement. Neuroimaging studies demonstrate structural and functional alterations in auditory and associative brain regions in individuals with hearing loss. Emerging evidence suggests that HA and CI may improve cognitive performance and potentially attenuate decline, although long-term randomized data remain limited. Conclusions: Current evidence supports ARHL as a clinically relevant and potentially modifiable contributor to cognitive decline. Clarifying causal pathways and optimizing early hearing rehabilitation strategies represent key priorities for future dementia prevention research. Full article

Background/Objectives: Childhood hearing loss (HL) affects auditory, linguistic, and social development. Alongside conventional rehabilitation, music-based interventions have gained increasing attention for their potential to support both auditory and non-auditory domains. This narrative review aims to summarize current evidence on the use of music-based interventions in children with HL. Methods: A narrative review of the literature was conducted, examining studies involving pediatric cochlear implant or hearing aid users. Publications were categorized into three main areas: musical auditory perception, musical training, and music therapy. Results: Studies on musical auditory perception demonstrate persistent limitations in pitch and timbre perception in children with HL, while rhythmic abilities appear relatively preserved. Musical training interventions, particularly those targeting rhythm, have been associated with improvements in auditory perception, linguistic processing, and selected cognitive skills, although parental involvement and long-term designs remain limited. Existing literature on music therapy is scarce but suggests potential benefits extending beyond auditory skills to emotional regulation, social interaction, and quality of life. Conclusions: Music-based interventions represent a promising complementary approach in pediatric hearing rehabilitation. While musical training is more widely studied, music therapy is still underrepresented despite its holistic focus. Further structured studies are needed to define standardized protocols and outcome measures for music therapy in children with HL. Full article

This study aims to establish a protocol for measuring the postauricular muscle reflex (PAMR) and to characterize both short- and mid-latency responses under controlled conditions in adults with normal hearing. PAMR electromyography was recorded in 43 adults with normal hearing. Auditory stimuli (50 ms, 80–100 dB (A)) were presented at four frequencies (500, 1000, 2000, and 4000 Hz), with systematic variation in stimulation side (ipsilateral/contralateral) and eye position (forward/rotated). The influence of these factors on PAMR amplitude and latency was analyzed using linear mixed-effects models. A short-latency PAMR (10–25 ms) was observed in all but one participant in at least one frequency. Reflex amplitude was significantly affected by stimulation side, eye position, frequency, and intensity. Contralateral stimulation produced stronger responses than ipsilateral stimulation. Additionally, a mid-latency PAMR (37–50 ms) was identified in 91% of participants, exhibiting lower amplitude and a higher detection level compared to the short-latency response. The mid-latency reflex was also significantly influenced by experimental conditions. The data shows that PAMR can be reliably recorded under controlled conditions in normal-hearing adults and that both short- and mid-latency components are influenced by auditory and oculomotor factors. These results provide us with normative data that can serve as a reference for future investigations in clinical populations, such as cochlear implant users and individuals with hearing loss. Full article

Background: Active middle ear implants (AMEIs) provide an alternative auditory rehabilitation strategy for patients who cannot tolerate conventional hearing aids. However, clinical data regarding the outcomes of Vibrant Soundbridge (VSB) implantation using the incus short process (SP) coupler in older adults remain limited. Objective: This study aimed to evaluate the audiological outcomes, patient-reported hearing benefits, tinnitus improvement, and surgical safety of VSB implantation using the SP coupler in older adults with bilateral sloping sensorineural hearing loss. Methods: This retrospective study included 45 older male veterans (mean age 76.1 ± 5.3 years) with bilateral sloping sensorineural hearing loss who underwent unilateral VSB implantation with the SP coupler between 2019 and 2023. Functional hearing gain was assessed using preoperative and postoperative sound-field pure-tone thresholds. Patient-reported outcomes were evaluated using the Speech, Spatial and Qualities of Hearing Scale (SSQ) and the Tinnitus Handicap Inventory (THI). Operative characteristics and postoperative complications were also analyzed. Results: Mean operative time was 40.2 ± 8.7 min. Functional hearing gain increased progressively across speech-critical frequencies, reaching +20 dB at 2 kHz and +30 dB at 4 kHz. The mean four-frequency pure tone average improved from 57.4 ± 8.3 dB HL preoperatively to 35.6 ± 6.9 dB HL postoperatively (p < 0.001). All SSQ subdomains showed significant improvement (p < 0.001). THI scores decreased significantly from 43.2 ± 8.4 to 17.1 ± 6.2 (p < 0.0001), with clinically meaningful tinnitus improvement observed in 75.6% of patients. No major surgical complications occurred. Conclusions: Vibrant Soundbridge implantation using the incus short process coupler provides effective auditory rehabilitation for older adults with sloping sensorineural hearing loss. The procedure yields meaningful high-frequency hearing gain, improved hearing-related quality of life, and significant tinnitus reduction while maintaining a favorable surgical safety profile. Restoration of auditory input through active middle ear implantation may also contribute to improved central auditory processing in older adults. Full article

Background: Congenital hearing loss occurs in about 2 of every 1000 newborns, of which half probably have a genetic origin. In syndromic patients, hearing impairment often results from craniofacial malformations affecting the outer and middle ear. Anatomical limitations such as microtia or external auditory canal atresia often preclude conventional air-conduction hearing aids, leaving bone-conduction devices as one viable option. However, surgical intervention in such patients is challenging. This study aimed to evaluate the audiological outcomes, safety, and effectiveness of the Bonebridge BCI 602 implant in 10 patients with genetic syndromes. Methods: The case series was made up of 10 patients aged 6–45 years, each diagnosed with a congenital syndrome affecting the external and/or middle ear. All cases involved surgical implantation of the Bonebridge system. Audiological outcomes were evaluated in free-field conditions on the day of sound processor activation and at 3–6 months follow-up via pure-tone and speech audiometry. Results: All surgical procedures were completed without serious adverse events, and the incidence of postoperative complications was low. Audiological outcomes showed clinically significant hearing improvement in all patients following Bonebridge implantation. Post-implantation hearing thresholds ranged from 25 to 40 dB HL, with notable gains in speech perception in both quiet and noisy environments. Conclusions: The Bonebridge implant appears to be a safe and effective option for auditory rehabilitation in patients with hearing loss associated with various genetic syndromes involving craniofacial malformation. However, this complex patient population requires individual assessment, interdisciplinary evaluation, and careful surgical planning. Full article

Background/Objectives: Frequency-to-place mismatch between cochlear implant (CI) electrodes and cochlear tonotopy has been suggested to affect postoperative speech perception. This study aimed to examine the associations between frequency-to-place mismatch and speech perception outcomes across multiple linguistic levels in patients with CI and to assess how these associations change over time using postoperative computed tomography. Methods: This retrospective cohort study included 44 postlingually deafened adults who underwent unilateral cochlear implantation with a Flex28 electrode by a single surgeon at a tertiary care hospital. Speech perception was assessed using CI-2004, a Japanese speech perception test consisting of monosyllables, consonants, words, and sentences, in quiet settings at 3, 6, and 12 months after CI activation. Partial correlation analyses between frequency-to-place mismatch and postoperative speech perception scores were performed in 35 of the 44 patients, controlling for age and mean preoperative pure-tone thresholds. Results: Negative associations were observed between frequency-to-place mismatch and CI-2004 scores, particularly for monosyllable and consonant perception in uncorrected analyses. After correction for multiple comparisons, only consonant perception at 3 months after CI activation remained significant (r = −0.52, p = 0.002). Similar patterns were observed for other speech measures and at later time points, although these did not remain significant after correction. Conclusions: Frequency-to-place mismatch was associated with postoperative speech perception outcomes, particularly those involving phoneme-level recognition. After correction for multiple comparisons, only consonant perception at 3 months after CI activation remained significant. Full article

Background/Objectives: Receptive vocabulary is essential for children’s language, academic, and cognitive development. While cochlear implants (CIs) help children with severe to profound hearing loss develop spoken language, their vocabulary skills often fall behind their typical hearing (TH) peers, although early implantation and auditory-verbal therapy (AVT) can help narrow this gap. Children with CIs and other developmental difficulties face additional challenges, but can still progress, with outcomes depending on the disabilities’ type and severity. Limited research exists on Arabic-speaking children with CIs, where cultural factors may delay intervention, and outcomes vary widely. It remains unclear how well these children develop receptive vocabulary compared to hearing peers and which factors influence their progress. Methodology: A multicenter, cross-sectional study in six GCC hospitals compared 103 children with CIs to a control group of 94 children with TH. Children with CIs were divided into those with and without additional difficulties. Receptive vocabulary was evaluated utilizing the Peabody Picture Vocabulary Test, Fifth Edition. Results: Children with CIs in the GCC scored lower (mean 89.5; SD = 20.5) than the TH control group (mean 104; SD = 16.8). Children with CIs without additional difficulties (mean 97.7; SD = 18.8) scored similarly to TH, while children with CIs and additional difficulties scored significantly lower (mean 76.7; SD = 15). Age at switch-on and presence of additional difficulties significantly affected receptive vocabulary outcomes. Conclusions: Children with CI who have no additional disabilities can reach receptive vocabulary levels similar to typical hearing peers, while those with extra difficulties show very diverse outcomes and continue to face challenges. Full article

Reconstruction of the ear and temporal region presents unique challenges due to the complex anatomy of the lateral skull base and the need to restore both structural integrity and auditory function. Historically managed as separate entities, auricular reconstruction and hearing rehabilitation are increasingly approached in an integrated manner, supported by advances in microsurgical techniques and implantable hearing technologies. This narrative review synthesizes contemporary evidence on microsurgical reconstruction of the ear and temporal region in conjunction with hearing rehabilitation, analyzing a wide range of existing surgical techniques in an integrative manner. Reconstructive techniques discussed include local and regional flaps, free tissue transfer, auricular framework reconstruction using autologous cartilage or alloplastic materials, external auditory canal reconstruction, and subtotal petrosectomy. Hearing rehabilitation options reviewed encompass bone-anchored hearing systems, active and passive transcutaneous devices, middle ear implants, and cochlear implantation. Simultaneous reconstruction and implantation may reduce surgical burden and enable earlier hearing restoration in carefully selected patients, while staged approaches remain advantageous in complex or high-risk scenarios, particularly in the presence of chronic infection or extensive temporal bone surgery. Multidisciplinary collaboration, meticulous preoperative planning, and long-term follow-up are essential to optimize outcomes. Full article

Background/Objectives: The OPA1 gene encodes a dynamin-related GTPase essential for mitochondrial fusion. Variants in OPA1 are a major cause of autosomal dominant optic atrophy (DOA). A subset of DOA patients exhibits hearing loss, often manifesting as auditory neuropathy spectrum disorder (ANSD). In this study, we aimed to describe the frequency of OPA1-related hearing loss in a large cohort of patients with hearing loss and to explore the genotype–phenotype correlations and appropriate interventions. Methods: A total of 18,475 Japanese patients with hearing loss were recruited. Targeted massively parallel sequencing of 158 deafness-related genes was performed, and individuals with OPA1 variants were identified. Clinical data, including age of onset, audiological findings, and systemic features, were retrospectively reviewed. Results: Ten individuals from eight independent families carrying OPA1 variants were identified. Three variants were classified as pathogenic or likely pathogenic, while five were variants of uncertain significance. Hearing loss was typically post-lingual in onset and progressive, with predominantly mild-to-moderate severity. Missense variants tended to be associated with DOA-plus phenotypes and ANSD. Five patients obtained only limited benefit from hearing aids, whereas one patient who received a cochlear implant achieved good speech perception. Conclusions: OPA1 is a rare causative gene for hearing loss and is frequently associated with the ANSD phenotype. Affected individuals exhibited phenotypic heterogeneity, which may reflect incomplete penetrance or the influence of mitochondrial DNA-related factors. Full article

Auditory Brain–Computer Interfaces (BCIs) constitute the vital intervention for profound sensorineural hearing loss where the auditory nerve is compromised, yet their clinical efficacy remains restricted by substantial biological bottlenecks and limited spectral resolution. This review critically examines the evolutionary paradigm of auditory restoration, tracing the transition from static physical replacement to dynamic biological symbiosis. We systematically analyze physiological barriers across cochlear, brainstem, and cortical levels, elucidating how rigid interfaces provoke chronic tissue responses and why linear encoding protocols fail in distorted central tonotopy. The article synthesizes emerging methodologies in material science, demonstrating how soft, bio-integrated electronics and biomimetic topologies effectively address mechanical impedance mismatches. Furthermore, the trajectory of neural encoding is evaluated, highlighting the paradigm shift from traditional envelope extraction to deep learning-driven non-linear mapping and adaptive closed-loop neuromodulation. Finally, the potential of high-resolution modulation techniques, including optogenetics and sonogenetics, alongside AI-facilitated intent perception for active listening, is assessed. It is concluded that future neuroprostheses must evolve into symbiotic systems capable of seamlessly integrating with neural plasticity to enable high-fidelity cognitive reconstruction. Full article

Objective: The aim was to evaluate cochlear implantation (CI) outcomes in children with Down syndrome (DS) with severe-to-profound sensorineural hearing loss (SNHL), addressing a literature gap and discussing challenges including anatomical abnormalities, cognitive deficits, and Eustachian tube dysfunction. Data Sources: Systematic searches were conducted in PubMed, Web of Science, Scopus, and Embase from inception through to June 2025. Review Methods: A systematic review adhering to PRISMA guidelines was performed. Included studies reported CI outcomes in DS patients receiving otolaryngologic care for SNHL. Extracted data included findings on ear anatomy, auditory performance, speech/language development, intelligibility, and duration of CI use. Results: A total of 149 abstracts were screened, yielding six studies with 26 patients that met the inclusion criteria. The review included pediatric DS patients with documented ages at implantation spanning from 11 months to 17.9 years. CI provided significant benefits for DS patients, including improved audiometric results, enhanced environmental awareness, and psychosocial gains. Optimal outcomes were associated with early implantation, thorough preoperative imaging (CT/MRI), and management of middle ear disease. Variability in outcomes often reflected cognitive limitations and anatomical challenges such as cochlear nerve hypoplasia and Eustachian tube dysfunction. Conclusions: CI can significantly improve quality of life and communication in children with DS when tailored to their unique needs. Preoperative imaging is essential to assess candidacy, and middle ear disease should be addressed prior to surgery. Clinicians should counsel families with individualized goals that emphasize functional hearing gains over normative speech benchmarks. Broader adoption of CI in this population may be supported by standardized, population-sensitive outcome measures and future prospective studies. Full article

Over the past four decades, tinnitus research has grown into a highly interdisciplinary field spanning auditory science, neuroscience, psychology, and clinical medicine. Yet how knowledge across subfields has been inherited, diversified, and integrated over time still lacks traceable structural evidence. To address this gap and move beyond frequency-oriented reviews and bibliometric studies that mainly report “hot topics” and prolific contributors, the present study reconstructs the intellectual evolution of tinnitus research (1984–2025) using citation-network-based main path analysis (MPA). From the Web of Science Core Collection, 6584 records were initially retrieved, of which 6354 formed a mutually linked core citation network (96.5%), indicating high coverage and analyzability. SPLC (Search Path Link Count)–weighted MPA was applied to extract global and key-route main paths capturing dominant knowledge trajectories and major branches. Cluster and co-word analyses were then integrated to delineate seven evolutionary stages and five major thematic clusters. This framework identifies bridging works and turning points and reveals how emerging lines—neuromodulation, implant-related treatments, and digital/telehealth CBT—branch from and later converge with established neurobiological and psychological pathways rather than appearing in isolation. Overall, the field has progressed from early psychoacoustics and spontaneous otoacoustic emissions through cochlear-injury plasticity, central gain, and limbic–auditory network models, and most recently toward mechanism-oriented diagnostics, individualized assessment, and targeted interventions. Full article