Search Results (146)

Background: Through the direct electrical stimulation of spiral ganglion neurons (SGNs) of the hearing nerve, cochlear implants overcome functionally impaired or missing hair cells in patients with profound to severe hearing loss. In routine clinical fitting, regions with severe local SGN degeneration (modiolar “dead regions”) cannot be identified. As a result, the electrical fields of neighboring electrodes are broadened, which can lead to increased channel interaction and, consequently, poorer speech understanding and hearing. The objective of this study was to ascertain whether neural health status can be evaluated by using cochlear implants’ inbuilt measures. Methods: Electrode impedance (MP1-, MP2-, MP1/MP2-, common ground mode), transimpedance matrix (TIM) and electrically evoked compound action potential (eCAP) measurements were performed before and after laser-induced induction of lesions on the modiolus of the guinea pig. Laser treatment-related shifts in impedance, TIM, and eCAP characteristics (threshold, amplitude, and a modified version of the failure index, referred to as the efficiency index (EI)) were correlated with the histologically assessed damage in three predefined areas of the basal modiolus within the electrode region. Results: Modiolar damage resulted in a significant reduction in the electrode impedance in MP2- and MP1/2-mode, the eCAP amplitude, and the EI. In contrast, TIM values and eCAP thresholds were significantly elevated. MP1, MP1/MP2 electrode impedance, TIM, and the eCAP thresholds were not correlated with the extent of modiolar damage. The shifts in eCAP amplitudes and the EI were significantly correlated with the damage at all regions of the basal modiolus. Conclusions: The eCAP amplitude and the EI are both capable of objectively evaluating the neural health status of the cochlea. Thus, a modiolar dead region could be expected from a local drop in eCAP amplitude values or the modified EI within the electrode array. Full article

Background/Objectives: Single-sided deafness (SSD) impairs speech perception, reduces spatial hearing, decreases quality of life, and is frequently accompanied by tinnitus. Cochlear implantation (CI) has become an established treatment option, but long-term prospective evidence across multiple functional and psychological domains remains limited. This study investigated auditory performance, subjective hearing outcomes, tinnitus burden, and psychological well-being over a two-year follow-up in a large SSD cohort. Methods: Seventy adults with SSD underwent unilateral CI. Assessments were conducted preoperatively and at 6 months, 1 year, and 2 years postoperatively. Outcome measures included the Freiburg Monosyllable Test (FS), Oldenburg Inventory (OI), Nijmegen Cochlear Implant Questionnaire (NCIQ), Tinnitus Questionnaire (TQ), Perceived Stress Questionnaire (PSQ), Generalized Anxiety Disorder scale (GAD-7), and General Depression Scale (ADS-L). Longitudinal changes were analyzed using Wilcoxon signed-rank tests with effect sizes; Holm-adjusted p-values were applied for baseline-to-follow-up comparisons. Results: Speech perception improved markedly within the first 6 months and remained stable through 2 years, with large effect sizes. All OI subdomains demonstrated early and sustained improvements in subjective hearing ability. Several hearing-related quality-of-life domains assessed by the NCIQ, particularly social interaction, self-esteem, and activity participation, showed medium-to-large long-term improvements. Tinnitus severity decreased substantially, with marked reductions observed by 6 months and maintained thereafter; the proportion of tinnitus-free patients increased at follow-up, although tinnitus symptoms persisted in a substantial subset of participants. Perceived stress was reduced initially at the early follow-up and remained below baseline thereafter. Anxiety and depressive symptoms mostly stayed within nonclinical ranges, showing no lasting changes after adjusting for multiple comparisons. Conclusions: In this prospective cohort, cochlear implantation was associated with durable improvements in auditory outcomes, tinnitus burden, and selected patient-reported quality-of-life domains over two years. Although significant functional and patient-centered improvements were noted, persistent tinnitus and diverse psychosocial outcomes underscore the need for personalized counseling and comprehensive follow-up that incorporate patient-reported outcomes and psychological assessments. Full article

Background/Objectives: Hearing impairment in middle-aged adults is a significant, modifiable risk factor for cognitive decline and dementia, and therapy with hearing aids or cochlear implants has been suggested to reduce this risk. However, most research on auditory rehabilitation and cognition has focused on older adults, and evidence regarding cognitive outcomes in middle-aged adults remains scarce despite this group being identified as critical for dementia prevention. Thus, this study aimed to assess cognitive skills in middle-aged hearing-impaired individuals 1 year after receiving a cochlear implant (CI) as part of auditory rehabilitation. Methods: Thirty-two patients with a mean age of 52.4 were enrolled in a prospective pre-post study. Hearing was tested using the Freiburg Monosyllable Test (FS) and the Oldenburg Inventory (OI). Cognitive performance was assessed using the WAIS-IV, operationalized through the Working Memory Index (Digit Span, Arithmetic) and Processing Speed Index (Symbol Search, Coding). Quality of life was assessed with the NCIQ, tinnitus-related distress with the Tinnitus Questionnaire (TQ), and depressive symptoms with the ADS-L. Results: After one year, speech intelligibility (FS) improved from a median of 0 to 70.0 (Wilcoxon Z = −4.864, p < 0.001, r = −0.61), and subjective hearing from a median of 2.55 to 3.18 (Wilcoxon Z = −3.072, p = 0.002). The NCIQ score increased from 52.3 to 60.6 (Z = −3.899, p < 0.001), and tinnitus-related distress decreased from 25 to 21 (Wilcoxon Z = −2.209, p = 0.027). Depressive symptoms declined numerically, although this change did not reach statistical significance. Working memory improved from 82.0 to 89.0 (Wilcoxon Z = −4.090, p < 0.001), and processing speed from 89.5 to 95.5 (Wilcoxon Z = −2.533, p = 0.011). Before CI, WMI and PSI showed a strong correlation (ρ = 0.533, p = 0.002), and WMI correlated moderately with education level (ρ = 0.452, p = 0.012). One year after CI, correlations strengthened between PSI and NCIQ (ρ = 0.510, p = 0.006), PSI and OI (ρ = 0.400, p = 0.039), and WMI and TQ (ρ = –0.459, p = 0.021), indicating emerging associations between cognitive outcomes and auditory or psychosocial measures. Conclusions: One year of CI-based auditory rehabilitation improves auditory function, quality of life, tinnitus distress, and—critically—working memory and processing speed in middle-aged adults. These findings address a previously unfilled research gap and support the relevance of CIs for preserving cognitive health during midlife. Full article

Background/Objectives: Retrocochlear auditory dysfunctions (RADs), including auditory neuropathy (AN) and auditory processing disorders (APD), encompass disorders characterized by impaired auditory processing beyond the cochlea. This narrative review critically examines their distinguishing features, synthesizing recent advances in classification, pathophysiology, clinical presentation, and treatment. Methods: This narrative review involved a comprehensive literature search across major electronic databases (e.g., PubMed, Scopus) to identify and synthesize relevant studies on the classification, diagnosis, and management of AN and APD. The goal was to update the view on etiologies (genetic/non-genetic) and individualized rehabilitative strategies. Diagnosis relies on a comprehensive assessment, including behavioral, electrophysiological, and imaging tests. Rehabilitation is categorized into bottom-up and top-down approaches. Results: ANSD is defined by neural desynchronization with preserved outer hair cell function, resulting in abnormal auditory brainstem responses and poor speech discrimination. The etiologies (distal/proximal) influence the prognosis for interventions, particularly cochlear implants (CI). APD involves central processing deficits, often with normal peripheral hearing and heterogeneous symptoms affecting speech perception and localization. Rehabilitation is multidisciplinary, utilizing bottom-up strategies (e.g., auditory training, CI) and compensatory top-down approaches. Remote microphone systems are highly effective in improving the signal-to-noise ratio. Conclusions: Accurate diagnosis and personalized, multidisciplinary management are crucial for optimizing communication and quality of life. Evidence suggests that combined bottom-up and top-down interventions may yield superior outcomes. However, methodological heterogeneity limits the generalizability of protocols, highlighting the need for further targeted research. Full article

This study aims to examine the acoustic characteristics of Mandarin vowels produced by children with cochlear implants and to explore the differences in their speech production compared with those of children with normal hearing. We propose a multiview model-based method for vowel feature analysis. This approach involves extracting and fusing formant features, Mel-frequency cepstral coefficients (MFCCs), and linear predictive coding coefficients (LPCCs) to comprehensively represent vowel articulation. We conducted k-means clustering on individual features and applied multiview clustering to the fused features. The results showed that children with cochlear implants formed discernible vowel clusters in the formant space, though with lower compactness than those of normal-hearing children. Furthermore, the MFCCs and LPCCs features revealed significant inter-group differences. Most importantly, the multiview model, utilizing fused features, achieved superior clustering performance compared to any single feature. These findings demonstrated that effective fusion of frequency domain features provided a more comprehensive representation of phonetic characteristics, offering potential value for clinical assessment and targeted speech intervention in children with hearing impairment. Full article

Hearing loss is increasingly recognized as a major public health concern among young adults, who are traditionally considered a low-risk group. This narrative review synthesizes recent evidence on risk and aggravating factors of early-onset hearing impairment, including recreational and occupational noise exposure, genetic susceptibility, infections, ototoxic medications, and lifestyle contributors. Pathophysiological mechanisms include cochlear synaptopathy, oxidative stress, excitotoxicity, vascular compromise, and immune-mediated injury. Global Burden of Disease data and World Health Organization reports indicate that more than one billion young people are at risk due to unsafe listening practices. Studies highlight emerging risk factors such as hidden hearing loss, extended high-frequency impairment and associations with COVID-19. Aggravating factors include delayed diagnosis, cumulative exposures and lack of preventive strategies. Early detection via advanced audiological assessments, such as extended high-frequency audiometry, otoacoustic emissions, speech-in-noise testing and auditory brainstem responses, is critical to prevent permanent damage. Public health interventions—particularly safe listening campaigns, early screening and monitoring in high-risk populations—are essential to reduce long-term disability. Full article

Classroom acoustics and noise exposure significantly impact students’ emotional, cognitive, and academic well-being. This study investigates how classroom noise and acoustics affect auditory and cognitive performance among 131 children in three primary schools in northeast Italy. Student performance was assessed using standardised tests evaluating working memory, verbal short and long-term memory, and visuospatial memory. Children were tested under two distinct acoustic conditions: ambient classroom noise and artificially induced noise (comprising a sequence of typical internal and external classroom sounds, intelligible speech, and unintelligible conversations). Prior to testing, hearing threshold was assessed, in order to reveal any existing impairments. Following each experimental session, children rated their perceived effort and fatigue in completing the tests. Acoustic characterisation of empty classrooms was performed using Reverberation Time (T₂₀), Clarity (C₅₀), and Speech Transmission Index (STI), while noise level was measured during all testing phases. Regression analysis was employed to correlate noise levels and reverberation times with class-average performance and perception scores. Results indicate that noise significantly impaired both verbal working memory and visual attention, increasing perceived effort and fatigue. Notably, both ambient and induced noise conditions exhibited comparable adverse effects on attentional and memory task performance. These findings underscore the critical importance of acoustic design in educational environments and provide empirical support for developing classroom acoustic standards. Full article

Background: Parkinson’s disease (PD) is a prevalent neurodegenerative disorder among the elderly, with its incidence increasing as the population ages. Despite the predominance of patients with PD aged 75 years and older in clinical settings, limited research has focused on their rehabilitation. This study aimed to compare the clinical characteristics and rehabilitation outcomes of elderly patients aged 75 years and older. Methods: A retrospective analysis was conducted on 141 patients with PD aged 65 years and older who underwent intensive inpatient rehabilitation. Patients were categorized into two subgroups: the young-old group (65–74 years, n = 58) and the old-old group (≥75 years, n = 83). The rehabilitation program included daily 2 h sessions, 6 days a week, combining physical, occupational, and speech–language–hearing therapies to enhance functional impairments and activities of daily living (ADL). Clinical characteristics and rehabilitation outcomes were compared between these groups. Results: The old-old group exhibited significantly higher rates of sarcopenia, higher Unified Parkinson’s Disease Rating Scale (UPDRS) scores, poorer balance scores and cognitive function, and lower ADL scores compared with the young-old group. However, both groups demonstrated significant improvements in UPDRS, Berg Balance Scale, 10 m walk test, and Functional Independence Measure scores, indicating enhanced motor function and ADL. Conclusions: Our retrospective study suggests that inpatient rehabilitation is associated with improvement in parkinsonism, motor symptoms, and ADL in patients with PD aged 75 years or older, highlighting the potential benefits of intensive rehabilitation even in advanced age. These findings underscore the need for prospective studies to confirm these effects. Trial registration: UMIN000056042 (last amendment 5 November 2024, retrospectively registered). Full article

Effective communication between deaf–mute and visually impaired individuals remains a challenge in the fields of human–computer interaction and accessibility technology. Current solutions mostly rely on single-modal recognition, which often leads to issues such as semantic ambiguity and loss of emotional information. To address these challenges, this study proposes a lightweight multimodal fusion framework that combines gestures and micro-expressions, which are then processed through a recognition network and a speech synthesis module. The core innovations of this research are as follows: (1) a lightweight YOLOv5s improvement structure that integrates residual modules and efficient downsampling modules, which reduces the model complexity and computational overhead while maintaining high accuracy; (2) a multimodal fusion method based on an attention mechanism, which adaptively and efficiently integrates complementary information from gestures and micro-expressions, significantly improving the semantic richness and accuracy of joint recognition; (3) an end-to-end real-time system that outputs the visual recognition results through a high-quality text-to-speech module, completing the closed-loop from “visual signal” to “speech feedback”. We conducted evaluations on the publicly available hand gesture dataset HaGRID and a curated micro-expression image dataset. The results show that, for the joint gesture and micro-expression tasks, our proposed multimodal recognition system achieves a multimodal joint recognition accuracy of 95.3%, representing a 4.5% improvement over the baseline model. The system was evaluated in a locally deployed environment, achieving a real-time processing speed of 22 FPS, with a speech output latency below 0.8 s. The mean opinion score (MOS) reached 4.5, demonstrating the effectiveness of the proposed approach in breaking communication barriers between the hearing-impaired and visually impaired populations. Full article

Sign language recognition aims to capture and classify hand and arm motion signals to enable intuitive communication for individuals with hearing and speech impairments. This study proposes a real-time Chinese Sign Language (CSL) recognition framework that integrates a dual-stage segmentation strategy with a lightweight three-layer artificial neural network to achieve early gesture prediction before completion of motion sequences. The system was evaluated on a 21-class CSL dataset containing several highly similar gestures and achieved an accuracy of 91.5%, with low average inference latency per cycle. Furthermore, training set truncation experiments demonstrate that using only the first 50% of each gesture instance preserves model accuracy while reducing training time by half, thereby enhancing real-time efficiency and practical deployability for embedded or assistive applications. Full article

This research presents a novel, real-time Pakistani Sign Language (PSL) recognition system utilizing a custom-designed sensory glove integrated with advanced machine learning techniques. The system aims to bridge communication gaps for individuals with hearing and speech impairments by translating hand gestures into readable text. At the core of this work is a smart glove engineered with five resistive flex sensors for precise finger flexion detection and a 9-DOF Inertial Measurement Unit (IMU) for capturing hand orientation and movement. The glove is powered by a compact microcontroller, which processes the analog and digital sensor inputs and transmits the data wirelessly to a host computer. A rechargeable 3.7 V Li-Po battery ensures portability, while a dynamic dataset comprising both static alphabet gestures and dynamic PSL phrases was recorded using this setup. The collected data was used to train two models: a Support Vector Machine with feature extraction (SVM-FE) and a Long Short-Term Memory (LSTM) deep learning network. The LSTM model outperformed traditional methods, achieving an accuracy of 98.6% in real-time gesture recognition. The proposed system demonstrates robust performance and offers practical applications in smart home interfaces, virtual and augmented reality, gaming, and assistive technologies. By combining ergonomic hardware with intelligent algorithms, this research takes a significant step toward inclusive communication and more natural human–machine interaction. Full article

Objectives: Dementia and hearing loss are prevalent conditions among older adults. This study aimed to determine the association between hearing loss and cognitive status using data from the Catholic Medical Center Clinical Data Warehouse (CMC–CDW). Methods: A retrospective review was conducted using the CMC–CDW. A total of 801 participants, aged 60 years and older, underwent bilateral speech audiometry and cognitive assessments using the Korea Mini-Mental State Examination (K–MMSE) and the Seoul Neuropsychological Screening Battery (SNSB). Results: The mean age of the participants was 77.1 ± 9.7 years, and the sex distribution was 313 males and 488 females. The mean speech recognition threshold was 39.6 ± 4.8 dB, and the average speech discrimination score was 74.3 ± 29.9%. The mean K–MMSE score was 25.1 ± 4.3. Cognitive status was categorized as normal (n = 205), mild cognitive impairment (n = 438), and dementia (n = 158). Logistic regression revealed that age, sex, and hearing loss were significantly associated with cognitive impairment (p < 0.05). Conclusions: These findings suggest that the association between hearing loss and cognitive impairment may be observed even at a mild stage of hearing loss, highlighting the need for early evaluation and management in older adults. Full article

Background: Cochlear implants (CIs) are transformative neuroprosthetics that restore speech perception for individuals with severe-to-profound hearing loss. However, temporal envelope cues are well-represented within the signal processing, while spectral envelope cues are poorly accessed by CI users, resulting in substantial deficits compared to normal-hearing individuals. This profoundly impairs the perception of complex auditory stimuli like music and vocal prosody, significantly impacting users’ quality of life, social engagement, and artistic expression. Methods: This narrative review synthesizes research on CI signal-processing limitations, perceptual and production challenges in music and singing, the role of the auditory–motor feedback loop, and strategies for improvement, including rehabilitation, technology, and the influence of neuroplasticity and sensitive developmental periods. Results: The degraded signal causes marked deficits in pitch, timbre, and vocal emotion perception. Critically, this impoverished input functionally breaks the high-fidelity auditory–motor feedback loop essential for vocal control, transforming it from a precise fine-tuner into a gross error detector sensitive only to massive pitch shifts (~6 semitones). This neurophysiological breakdown directly causes pervasive pitch inaccuracies and melodic distortion in singing. Despite these challenges, improvements are possible through advanced sound-processing strategies, targeted auditory–motor training that leverages neuroplasticity, and capitalizing on sensitive periods for auditory development. Conclusions: The standard CI signal creates a fundamental neurophysiological barrier to singing. Overcoming this requires a paradigm shift toward holistic, patient-centered care that moves beyond speech-centric goals. Integrating personalized, music-based rehabilitation with advanced CI programming is essential for improving vocal production, fostering musical engagement, and ultimately enhancing the overall quality of life for CI users. Full article

Background and Clinical Significance: developmental language disorder (DLD) and specific learning disorder (SLD) may coexist, resulting in significantly broader impairments to oral and written language skills. Understanding the neurobiological basis of these deficits is crucial, and electrophysiological assessment of the auditory system offers an objective approach not influenced by behavioral factors. The present study describes the audiological electrophysiology of an adolescent diagnosed with both DLD and SLD. Case Presentation: R.B., a 15-year-old adolescent with a history of SLD and DLD, presented with persistent deficits in oral language (syntax) and written (decoding) skills after 7 months of intensive therapy. Basic audiological tests confirmed hearing within normal limits. An electrophysiological battery, including the click-brainstem auditory evoked potential (c-ABR), medium latency auditory evoked potential (MLAEP), long-latency auditory evoked potential (P300), and frequency following response (FFR), was performed to investigate information processing in the auditory trajectory. The c-ABR confirmed the integrity of the auditory pathway up to the brainstem. MLAEP revealed a differential ear effect, with significant asymmetry in the Na-Pa interamplitude, pointing to a dysfunction in subcortical processing. The P300 showed a prolonged latency in the left ear (437 ms), and there was no response in the right. The FFRs under ideal and impaired listening conditions demonstrated impaired perception of speech and revealed that the neurophysiological responses did not correspond to the eliciting stimulus. Conclusions: The present case study showed that electrophysiological testing of the auditory system provided objective and quantitative evidence for a neurobiological basis of the language deficits of an adolescent with DLD and SLD. The work demonstrated that when comorbidities are present, a multidisciplinary investigation of both the linguistic and auditory systems can be helpful. Full article

Background/Objectives: Audiometric methods for hearing-impaired patients are constantly evolving as new therapeutic interventions and improved clinical standards are established. This study aimed to explore the relationship between patient-reported outcome measures in cochlear implant users and scores from audiometric test procedures in quiet and noise. Methods: In a prospective study, 20 postlingually deafened CI users were included. Speech comprehension was measured in quiet (by Freiburg words) and in noise (by the Oldenburg sentence test), while stationary speech-simulating or temporally fluctuating noise was applied and the noise sources were varied. Subjective feedback from the patients was obtained using the HISQUI19 questionnaire. Results: Word scores in quiet showed a significant positive correlation with the user’s subjective assessment of hearing ability using the questionnaire (Spearman’s R = 0.57). A greater correlation of the subjective evaluation of comprehension against fluctuating background noise as compared with stationary background noise was evident. On the other hand, the test–retest accuracy was reduced by a substantial factor in the transition from stationary to fluctuating background noise. Conclusions: By introducing temporal fluctuations in the background noise, the ecological validity can be improved, but at the cost of a parallel decrease in the accuracy of the test procedure. Especially in the context of studies, this knowledge may help to improve the choice of the specific test method used in evaluating the relationship between ecological validity and precision audiometry. Full article