Detecting Noise-Induced Cochlear Synaptopathy by Auditory Brainstem Response in Tinnitus Patients With Normal Hearing Thresholds: A Meta-Analysis

Noise-induced cochlear synaptopathy (CS) is defined as a permanent loss of synapses in the auditory nerve pathway following noise exposure. Several studies using auditory brainstem response (ABR) have indicated the presence of CS and increased central gain in tinnitus patients with normal hearing thresholds (TNHT), but the results were inconsistent. This meta-analysis aimed to review the evidence of CS and its pathological changes in the central auditory system in TNHT. Published studies using ABR to study TNHT were reviewed. PubMed, EMBASE, and Scopus databases were selected to search for relevant literature. Studies (489) were retrieved, and 11 were included for meta-analysis. The results supported significantly reduced wave I amplitude in TNHT, whereas the alternations in wave V amplitude were inconsistent among the studies. Consistently increased V/I ratio indicated noise-induced central gain enhancement. The results indicated the evidence of noise-induced cochlear synaptopathy in tinnitus patients with normal hearing. However, inconsistent changes in wave V amplitude may be explained by that the failure of central gain that triggers the pathological neural changes in the central auditory system and/or that increased central gain may be necessary to generate tinnitus but not to maintain tinnitus.

The DizzyQuest: relation between self-reported hearing loss, tinnitus and objective hearing thresholds in patients with Meniere’s disease

Background Combining a mobile application-based vestibular diary called the DizzyQuest and an iPad-based hearing test enables evaluation of the relationship between experienced neuro-otological symptoms and hearing thresholds in daily life setting. The aim was to investigate the relationship between self-reported hearing symptoms and hearing thresholds in patients with Meniere’s disease (MD), using the DizzyQuest and the iPad-based hearing test simultaneously. Methods The DizzyQuest was administered for 3 weeks in 21 patients. Using the experience-sampling-method (ESM), it assessed hearing loss and tinnitus severity for both ears separately. Each day after the DizzyQuest, an iPad-based hearing test was used to measure hearing thresholds. A mixed model regression analysis was performed to investigate relationships between hearing thresholds and self-reported hearing loss and tinnitus severity. Results Fifteen patients were included. Overall, pure-tone averages (PTAs) were not correlated with self-reported hearing loss severity and tinnitus. Individual differences in PTA results between both ears did not significantly influence the difference in self-reported hearing loss severity between both ears. Self-reported hearing loss and tinnitus scores were significantly higher in ears that corresponded with audiometric criteria of MD (p < 0.001). Self-reported tinnitus severity significantly increased with self-reported hearing loss severity in affected (p = 0.011) and unaffected ears (p < 0.001). Conclusion Combining the DizzyQuest and iPad-based hearing test, facilitated assessment of self-reported hearing loss and tinnitus severity and their relationship with hearing thresholds, in a daily life setting. This study illustrated the importance of investigating neuro-otological symptoms at an individual level, using multiple measurements. ESM strategies like the DizzyQuest should therefore be considered in neuro-otological research.

One Year Assessment of the Hearing Preservation Potential of the EVO Electrode Array

Background: A prospective longitudinal multicentre study was conducted to assess the one-year postsurgical hearing preservation profile of the EVOTM electrode array. Methods: Fifteen adults presenting indications of electro-acoustic stimulation (pure-tone audiometry (PTA) thresholds ≤70 dB below 750 Hz) were implanted with the EVO™ electrode array. Hearing thresholds were collected at five time-points from CI activation to twelve months (12M) after activation. Hearing thresholds and hearing preservation profiles (HEARRING group classification) were assessed. Results: All subjects had measurable hearing thresholds at follow-up. No case of complete loss of hearing or minimal hearing preservation was reported at any time point. At activation (Nact = 15), five participants had complete hearing preservation, and ten participants had partial hearing preservation. At the 12M time point (N12m = 6), three participants had complete hearing preservation, and three participants had partial hearing preservation. Mean hearing loss at activation was 11 dB for full range PTA and 25 dB for PTAs low-frequency (125–500 Hz). Conclusions: This study provides the first longitudinal follow-up on associated hearing profiles to the EVO™ electrode array, which are comparable to the literature. However, other studies on larger populations should be performed.

EDUKASI TENTANG GANGGUAN PENDENGARAN AKIBAT BISING KEPADA WARGA GENTENG KULON BANYUWANGI JAWA TIMUR

Noise can have an impact on hearing loss. Changes in hearing thresholds due to noise are some temporary but others potentially permanent. The impact of hearing loss must be controlled so the quality of life will not decrease. A cross-sectional study to assess the quality and increasing knowledge about noise-induced hearing loss was implemented with lectures, discussions and a pre-test before the activity and a post-test after the activity to assess the knowledge development. The polling was conducted to assess the participants' attitudes and psychomotor skills. The study was followed by 77 participants, most of whom were aged 20-30 years, namely 23 (30%). It was found that 16 people (20%) had complaints of hearing loss, 18 people (24%) often used headsets and earphones, 18 (23%) people worked in noisy places. The average pre-test result was 35.06 (+13.72) and the post-test was 77.9 (+20.81). Comparison of pre-test and post-test results of hearing health education obtained different results (p < 0.0001) significantly. Noise-induced hearing loss is permanent deafness and cannot be treated with medicine or surgery. Prevention is the most important thing from noise-induced hearing loss. The counseling education about noise-induced hearing loss on community must always be performed as an prevention and early detection.Keywords: deafness, noise induce hearing loss, prevention, education AbstrakBising dapat berdampak terhadap gangguan pendengaran. Perubahan batas pendengaran akibat bising yang bersifat sementara, dan perubahan batas pendengaran akibat bising yang bersifat menetap. Dampak gangguan pendengaran harus dikendalikan agar tidak menimbulkan penuruna kualitas kehidupan. Studi cross sectional untuk menilai kualitas dan upaya peningkatan pengetahuan tentang gangguan pednegaran akibat bising dilaksanakan dengan ceramah, diskusi dan dilakukan pre test sebelum kegiatan dan post test setelah kegiatan untuk menilai peningkatan pengetahuan. Survei jajak pendapat dilakukan untuk menilai sikap dan psikomotor peserta. Studi diikuti 77 peserta, usia terbanyak di usia 20 – 30 tahun yaitu 23 orang (30%). Didapatkan 16 orang (20%) mengalami keluhan gangguan pendengaran, 18 orang (24%) sering menggunakan headset dan earphone,18 (23%) orang bekerja di tempat bising. Hasil rata-rata pre test 35,06 (+13,72) dan rata-rata post test 77,9 (+20,81). Perbandingan hasil pre test dan post test penyuluhan kesehatan pendengaran didapatkan hasil yang berbeda signifikan (p < 0,0001). Tuli akibat bising merupakan tuli yang bersifat menetap dan tidak dapat diobati dengan obat maupun pembedahan, pencegahan merupakan hal yang terpenting dari tuli akibat bising atau noise induced hearing loss.Kegiatan edukasi penyuluhan gangguan pendengaran akibat bising harus senantiasa dilakukan di masyarakat sebagai upaya pencegahan dan deteksi dini.Kata kunci: Tuli, gangguan pendengaran karena bising, pencegahan, edukasi

Neuroplastin genetically interacts with Cadherin 23 and the encoded isoform Np55 is sufficient for cochlear hair cell function and hearing

Mammalian hearing involves the mechanoelectrical transduction (MET) of sound-induced fluid waves in the cochlea. Essential to this process are the specialised sensory cochlear cells, the inner (IHCs) and outer hair cells (OHCs). While genetic hearing loss is highly heterogeneous, understanding the requirement of each gene will lead to a better understanding of the molecular basis of hearing and also to therapeutic opportunities for deafness. The Neuroplastin (Nptn) gene, which encodes two protein isoforms Np55 and Np65, is required for hearing, and homozygous loss-of-function mutations that affect both isoforms lead to profound deafness in mice. Here we have utilised several distinct mouse models to elaborate upon the spatial, temporal, and functional requirement of Nptn for hearing. While we demonstrate that both Np55 and Np65 are present in cochlear cells, characterisation of a Np65-specific mouse knockout shows normal hearing thresholds indicating that Np65 is functionally redundant for hearing. In contrast, we find that Nptn-knockout mice have significantly reduced maximal MET currents and MET channel open probabilities in mature OHCs, with both OHCs and IHCs also failing to develop fully mature basolateral currents. Furthermore, comparing the hearing thresholds and IHC synapse structure of Nptn-knockout mice with those of mice that lack Nptn only in IHCs and OHCs shows that the majority of the auditory deficit is explained by hair cell dysfunction, with abnormal afferent synapses contributing only a small proportion of the hearing loss. Finally, we show that continued expression of NEUROPLASTIN in OHCs of adult mice is required for membrane localisation of Plasma Membrane Ca2+ ATPase 2 (PMCA2), which is essential for hearing function. Moreover, Nptn haploinsufficiency phenocopies Atp2b2 (encodes PMCA2) mutations, with heterozygous Nptn-knockout mice exhibiting hearing loss through genetic interaction with the Cdh23ahl allele. Together, our findings provide further insight to the functional requirement of Neuroplastin for mammalian hearing.

Neural correlates of masked and unmasked tones: psychoacoustics and late auditory evoked potentials (LAEPs)

Hearing thresholds can be used to quantify one's hearing ability. In various masking conditions, hearing thresholds can vary depending on the auditory cues. With comodulated masking noise and interaural phase disparity (IPD), target detection can be facilitated, lowering detection thresholds. This perceptual phenomenon is quantified as masking release: comodulation masking release (CMR) and binaural masking level difference (BMLD). As these measures only reflect the low limit of hearing, the relevance of masking release at supra-threshold levels is still unclear. Here, we used both psychoacoustic and electro-physiological measures to investigate the effect of masking release at supra-threshold levels. We investigated whether the difference in the amount of masking release will affect listening at supra-threshold levels. We used intensity just-noticeable difference (JND) to quantify an increase in the salience of the tone. As a physiological correlate of JND, we investigated late auditory evoked potentials (LAEPs) with electroencephalography (EEG). The results showed that the intensity JNDs were equal at the same intensity of the tone regardless of masking release conditions. For LAEP measures, the slope of the P2 amplitudes with a function of the level was inversely correlated with the intensity JND. In addition, the P2 amplitudes were higher in dichotic conditions compared to diotic conditions. Estimated the salience of the target tone from both experiments suggested that the salience of masked tone at supra-threshold levels may only be beneficial with BMLD.

Hearing Aid Selection: Closed- versus Open-canal Fitting Hearing Aids

To select hearing aid is an essential process for successful hearing rehabilitation. The purpose of this study is to review hearing aid selection considerations between receiver in-the-canal (RIC) and custom hearing aid (CHA) in order to guide appropriate selection of the hearing aid. This study discussed three key factors in the hearing aid selection including physical, acoustic and electroacoustic characteristics and other aspects. Advantages of RIC types are comfort to wear, reduction of the occlusion effect, presence of directional microphones, on-site fit, easy connectivity with other devices, and use of rechargeable batteries. On the other hand, the CHA types have their advantage in terms of being comfort to wear with masks, proper insertion and placement, reduction of the acoustic feedback, good approximation of frequency response curve, improvement of speech in noise perception, expanded hearing aid candidacy with varying hearing thresholds, and easy telephone use. We concluded that appropriate selection of the hearing aid would contribute to successful hearing rehabilitation, if considering physical, psycho-social, and acoustical characteristics.

Association of Metabolic Syndrome with Sensorineural Hearing Loss

The prevalence of sensorineural hearing loss has increased along with increases in life expectancy and exposure to noisy environments. Metabolic syndrome (MetS) is a cluster of co-occurring conditions that increase the risk of heart disease, stroke and type 2 diabetes, along with other conditions that affect the blood vessels. Components of MetS include insulin resistance, body weight, lipid concentration, blood pressure, and blood glucose concentration, as well as other features of insulin resistance such as microalbuminuria. MetS has become a major public health problem affecting 20–30% of the global population. This study utilized health examination to investigate whether metabolic syndrome was related to hearing loss. Methods: A total of 94,223 people who underwent health check-ups, including hearing tests, from January 2010 to December 2020 were evaluated. Subjects were divided into two groups, with and without metabolic syndrome. In addition, Scopus, Embase, PubMed, and Cochrane libraries were systematically searched, using keywords such as “hearing loss” and “metabolic syndrome”, for studies that evaluated the relationship between the two. Results: Of the 94,223 subjects, 11,414 (12.1%) had metabolic syndrome and 82,809 did not. The mean ages of subjects in the two groups were 46.1 and 43.9 years, respectively. A comparison of hearing thresholds by age in subjects with and without metabolic syndrome showed that the average pure tone hearing thresholds were significantly higher in subjects with metabolic syndrome than in subjects without it in all age groups. (p < 0.001) Rates of hearing loss in subjects with 0, 1, 2, 3, 4, and 5 of the components of metabolic syndrome were 7.9%, 12.1%, 13.8%, 13.8%, 15.5% and 16.3%, respectively, indicating a significant association between the number of components of metabolic syndrome and the rate of hearing loss (p < 0.0001). The odds ratio of hearing loss was significantly higher in subjects with four components of metabolic syndrome: waist circumference, blood pressure, and triglyceride and fasting blood sugar concentrations (p < 0.0001). (4) Conclusions: The number of components of the metabolic syndrome is positively correlated with the rate of sensorineural hearing loss.