Hearing Loss In Korea Research Articles

Noise-Induced and Age-Related Hearing Loss in Korea

Recently, reports of noise-induced hearing loss (NIHL) have sharply risen among workers in South Korea, almost 20-fold in 2022, compared to 2012. This is presumably because NIHL is combined with age-related hearing loss. For the correct diagnosis of NIHL, therefore, the effect of aging that contributes to threshold shifts is should be excluded, and that would require scrutinizing of various established methods. Additionally, international and domestic data from large cross-sectional studies may provide new insights in excluding the effect of age-related hearing loss in individuals in which threshold shifts occurred. This paper comprises the recommendations for the diagnosis and quantification of NIHL in a medico-legal context.

Analysis of Research Trends on Older Adults with Hearing Loss in Korea: Using the ICF Core Set

Purpose: This study aimed to analyze trends of research on older adults with hearing loss, based on the framework of the International Classification of Functioning, Disability and Health (ICF) core set for hearing loss in Korea, and to present implications for the direction and challenges of research on older adults with hearing loss in the future. Methods: A total of 54 studies related to older adults with hearing loss, published in academic journals from 2000 to July 2023 in Korea, were analyzed.Results: In the analysis of research methods, quantitative studies accounted for 97.0%, among which survey studies accounted for 56.7%, more than experimental studies. As a result of the analysis by research theme, studies related to ‘quality of life and satisfaction (21.1%)’ and ‘psychological and emotional characteristics (18.3%)’ were frequent. As a result of the analysis by the classification of the ICF core set, among the components of the ICF, studies related to ‘activities and participation’ and ‘body functions’ were the most. By subcategory, ‘hearing functions (12.0%)’ and ‘emotional functions (11.7%)’ of the body functions sub-area, and ‘listening (10.9%)’ of the activities and participation subarea were frequent.Conclusion: The results of this study will be useful as a foundational reference for the evaluation of hearing impairments of older adults with hearing loss, the development of hearing rehabilitation programs, and the establishment of various health and welfare policies.

Status of People with Hearing Loss in Korea: Findings of from the 2000 to 2020 Nationwide Survey of People with Disabilities

The purpose of this study is to understand the status of people with hearing loss in Korea based on findings from a nationwide survey of people with disabilities. The study investigated the statistics of people with hearing loss among the nationwide survey of people with disabilities from 2000 to 2020. Hearing loss population has been increased for the past 20 years and more than 70% of registered people with hearing loss in this study were over the age of 60. Cost issue was the main reason for not purchasing assistive devices (54%). Forty-seven point seven percent of respondents reported that communication difficulty was the reason for discomfort in outdoor activities. People with hearing loss reported that the highest the highest rate of discrimination experience (40.4%) from their peers during their school lives. They also felt that they did not receive much national support after registering their disability. 37% of the respondents used the national medical insurance in Korea for their assistive devices. National support for hearing loss should be considered from multiple aspects.

A situational analysis of ear and hearing care in South Korea using WHO ear and Hearing Care Situation Analysis tool.

The WHO emphasizes lifelong management of hearing diseases such as hearing loss and advocates for prevention. The Ear and Hearing Care Situation Analysis (EHCSA) tool was designed by the WHO for assessment and quality improvement of state-led management of hearing loss prevention and management programs. The purpose of this study was to use the EHCSA to assess the ear and hearing management program in Korea and to establish goals consistent with best practices for improving policies and services related to ear and hearing care. The EHCSA was used as a need assessment of the ear and hearing management services in the country. The EHCSA consists of two sections. Section 1 consists of 41 questions to evaluate health policies and support services. Section 2 consists of 203 questions to evaluate human resources and services of the ear and hearing management sector. There are an estimated 800,000 people with hearing loss in Korea. Policies such as hearing aid support are in place, and outreach services such as free hearing tests are also being actively conducted. In all medical institutions, ear and hearing management treatment and medication prescriptions could be received without barriers. Workers in the fields of ear and hearing management, such as audiologists, language therapists, special education teachers, and sign language interpreters, are specialized and have well-established guidelines for training. Overall, the domestic ear and hearing management sector has confirmed that policies and services are well-prepared in comparison with advanced countries such as the United States, Iran, and China. The use of the EHCSA was functional in collecting data on the current state of domestic ear and hearing management policies and services in Korea, can be used for continuous quality improvement and expansion of medical services, and can be used as a reporting mechanism to the WHO.

Factors Influencing Hearing Aid Adoption in Patients With Hearing Loss in Korea.

BackgroundThe purpose of this study was two-fold: 1) to identify differences in the characteristics of adopters and non-adopters of hearing aids (HAs); and 2) to investigate factors influencing the purchase of HA.MethodsThis study was conducted among 1,464 subjects (818 male and 646 female) with hearing loss. A national face-to-face survey was performed from August 2019 to October 2020 by otologists or HA experts. The questionnaire consisted of three domains: demographic, audiological, and HA-related domains. Multivariate logistic regression analysis was performed after adjusting for degree of hearing loss.ResultsThe mean age of the participants was 70.4 ± 12.2 years. Of the 1,464 respondents, 1,190 (81.3%) had already purchased HA. We identified educational level, household income, hearing loss period, place of HA purchase, and government HA assistance program status as factors influencing HA adoption. Among these factors, third party reimbursement was the most important factor affecting HA purchase intent. The main reasons for not adopting HA were feeling that their hearing was adequate, inability to afford HA, and perceptions that HA are uncomfortable.ConclusionVarious factors are involved in the purchase of HA, but disabled registration status and third party reimbursement were identified as the most critical factors. In the future, the government should take a more active role in increasing the distribution of HA to patients with hearing loss.

Justification for Integrated Care of Dementia and Presbycusis: Focused on National Dementia Policy

Dementia management has become one of essential factors in the national policy globally in terms of the elderly health care service. In the brief communication, we compared various national reports from other countries to see whether current care service for the dementia had integrative approach for the patients with hearing loss in Korea. We also discussed a need of systematic hearing care for the elderly with dementia who was also a suspected case of aged-related hearing loss because many studies had confirmed that untreated hearing loss has a negative effect on dementia and vice versa. After analyzing the national policy from several countries, we found that the systems had been well established to screen dementia patients by using various clinical tests in UK, Canada, and Japan who provided appropriate services by classifying types of the dementia. Remarkably, the hearing test was included as the testing protocol for the dementia in Canada and the experts such as speech pathologists and music therapists had worked in a non-pharmacotherapy program for the elderly with dementia in France. Unfortunately, the dementia policy of Korea needs to be refined when considering the hearing care/management in that the integrated management of hearing and dementia are important. In addition, the clinicians who work for the dementia care home need to know audiological knowledge. Since the auditory training and rehabilitation for the elderly can reduce increased rate of cognitive decline, we strongly recommend that auditory training should be a part of the cognitive rehabilitation programs in the dementia care home.

National representative analysis of unilateral hearing loss and hearing aid usage in South Korea.

A definitive study on the prevalence of adult unilateral hearing loss and hearing aid rehabilitation is lacking in Korea. The purpose of our study was to investigate the prevalence of adult unilateral hearing loss and the factors associated with hearing aid use in patients with unilateral hearing loss in South Korea. We obtained data from 2009 to 2012 from the Korea National Health and Nutrition Examination Surveys (KNHANES), a cross-sectional, nationwide and population-based survey in the Republic of Korea. We analyzed the prevalence and associated factors of unilateral hearing loss and hearing aid adoption by univariable and multivariable analysis. Unilateral hearing loss was defined as pure tone average ≥ 41 dB in the worse hearing ear, and < 41 dB in the other ear assessed at 0.5, 1.0, 2.0, and 3.0 kHz. From 2009 to 2012, 33,252 individuals participated in the KNHANES. Among them, the number of patients with unilateral hearing loss was 1632 (5.55%) and the prevalence of hearing aid adoption in unilateral hearing loss was 1.56%. We also compared the factors between hearing aid users and non-users. Occupational status (OR 3.759, 95% CI 1.443-9.804), the hearing threshold in the better ear (OR 1.088, 95% CI 1.029-1.151), and hearing threshold in the worse ear (OR 1.031, 1.005-1.058) were found to affect the adoption of hearing aids. The prevalence of noise exposure at work in hearing aid users was significantly lower than the prevalence of noise exposure at work in those with no hearing aid. The prevalence of hearing aid use in patients with unilateral hearing loss in Korea is very low compared to other countries. Public health education is needed to increase public awareness of unilateral hearing loss, hearing aid adoption and its continued usage. Auditory rehabilitation should be actively recommended to patients with unilateral hearing loss.

Genetic association of MYH genes with hereditary hearing loss in Korea

BackgroundMyosin is a key protein involved in regulating the shape and motility of cells. The MYH9 and MYH14 genes, which encode non-muscle myosin heavy chain IIA (NMMHC II-A) and IIC (NMMHC II-C), respectively, are expressed in the inner ear. These myosin genes are known to be associated with autosomal dominant non-syndromic hearing loss (ADNSHL); however, genetic studies in patients with ADNSHL in Korea have rarely been reported. MethodsWe analyzed the MYH9 and MYH14 genes in 75 Korean patients with ADNSHL. ResultsWe identified 4 possible pathogenic variants: a novel variant p.F1303L and 2 previously reported variants (p.R1730C and p.R1785C) in the MYH9 gene, and a novel variant p.A1868T in the MYH14 gene. All the variants were located in the myosin tail domain, which is essential for the interaction of myosin with actin. These variants were predicted to be possibly pathogenic by functional prediction tools and were absent in 100 unrelated normal controls. ConclusionThese results suggest that all the variants identified in this study have a strong potential to affect the structural stability and/or function of non-muscle myosin in the inner ear, which might lead to ADNSHL. This study establishes the link between the genotype and development of ADNSHL and contributes to the establishment of Korean database for hereditary hearing loss.

Noise Induced Hearing Loss in Korea

Noise Induced Hearing Loss in Korea

Rosmarinic Acid, Active Component of Dansam-Eum Attenuates Ototoxicity of Cochlear Hair Cells through Blockage of Caspase-1 Activity

Cisplatin causes auditory impairment due to the apoptosis of auditory hair cells. There is no strategy to regulate ototoxicity by cisplatin thus far. Dansam-Eum (DSE) has been used for treating the central nerve system injury including hearing loss in Korea. However, disease-related scientific investigation by DSE has not been elucidated. Here, we demonstrated that DSE and its component rosmarinic acid (RA) were shown to inhibit apoptosis of the primary organ of Corti explants as well as the auditory cells. Administration of DSE and RA reduced the thresholds of the auditory brainstem response in cisplatin-injected mice. A molecular docking simulation and a kinetic assay show that RA controls the activity of caspase-1 by interaction with the active site of caspase-1. Pretreatment of RA inhibited caspase-1 downstream signal pathway, such as the activation of caspase-3 and 9, release of cytochrome c, translocation of apoptosis-inducing factor, up-regulation of Bax, down-regulation of Bcl-2, generation of reactive oxygen species, and activation of nuclear factor-κB. Anticancer activity by cisplatin was not affected by treatment with RA in SNU668, A549, HCT116, and HeLa cells but not B16F10 cells. These findings show that blocking a critical step by RA in apoptosis may be useful strategy to prevent harmful side effects of ototoxicity in patients with having to undergo chemotherapy.

Age Related Hearing Loss in Korea: A Healthcare Center-based Study

Age Related Hearing Loss in Korea: A Healthcare Center-based Study

Application of allele-specific primer extension-based microarray for simultaneous multi-gene mutation screening in patients with non-syndromic hearing loss

Congenital hearing loss (HL) is the most common sensory disorder in humans, affecting one in 1000 infants at birth. A high degree of genetic heterogeneity makes it difficult to screen for mutations in all known deafness genes in clinical applications. We have improved a genotyping microarray using the multiplex PCR-based allele-specific primer extension (ASPE) reaction and applied this method for the genetic diagnosis of congenital HL in Korea. Seven different mutations in the GJB2, SLC26A4 and mitochondrial 12S rRNA genes, which were identified on the basis of a previous study in a Korean population, were selected for the study. These genes were used to evaluate the accuracy of the microarray. The test for validation of the current version of HL genotyping microarray was fully concordant with the results of DNA sequencing in which 51 subjects with non-syndromic HL were originally genotyped. Furthermore, the blind test of the genotyping microarray detected four different mutations in 10 out of 65 patients, and the accuracy of microarray was calculated as 98% (64/65). Therefore, our results suggest that this HL genotyping microarray will be useful in clinical applications for the genetic diagnosis of HL.

A Survey of Speech Perception Tests for Children with Hearing Loss Used in Cochlear Implant Centers in Korea

Background and ObjectivesZZVarious speech perception tests have been developed for children with hearing loss (HL) in Korea, although they are not standardized yet. This study aims to examine the actual condition of speech perception tests for children with HL in Korea. Subjects and MethodZZSurvey questionnaires and speech perception tests for children with HL were collected from 24 cochlear implant (CI) centers between March and July 2009. The speech perception tests were classified according to target ages, speech stimulus levels, and response formats. We interviewed speech therapists who had developed monosyllabic word (MW) tests, and gathered source materials, considerations, and limitations of the MW tests. We also analyzed vocabulary familiarity and phonetic balancing of words in the most commonly used MW tests. ResultsZZThirty-eight kinds of speech perception tests for children with HL were collected from 24 CI centers. Among these tests, open-set MW tests and sentence tests were used in all centers. Speech therapists responsible for developing MW tests had selected words from textbooks, storybooks, and spontaneous speech data to secure vocabulary familiarity and phonetic balancing within each list. Four commonly used MW tests revealed that vocabulary familiarity was compatible with commonly used MW in preschoolers and demonstrated a similar trend in phoneme frequencies. ConclusionZZThe results of this study showed that current speech perception tests for children with HL should be verified, revised, and standardized in an experimental setting. Korean J Otorhinolaryngol-Head Neck Surg 2010;53:534-46 Key WordsZZHearing loss·Cochlear implant·Children·Speech perception test.

Occupational Hearing Loss in Korea

In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed.