• Journal of Preventive Medicine and Public Health
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• v.28 no.3 s.51
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• pp.651-662
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• 1995

In Korea there is no specific method of age adjustment in noise induced hearing loss(NIHL). We attempted the age adjustment to understand the effects of age on the diagnosis of NIHL. We used the International Standard Organization 1999 as an age adjustment method. We used the 1, 617 otologically normal person's hearing data from a health examination center, and 206 workers diagnosed as NIHL. We concluded as follows; 1. The ISO 7029 function used for age specific hearing loss is not suited to Korean people. 2. The mean of age specific hearing loss is 11.0 6.2dB and the older of age, the more decrease on hearing loss, especially in 4000Hz. 3. The difference of NIHL between before age adjustment and after age adjustment in the 3rd decade is 5.4dB, in the 4th decade is 6.7dB, in the 5th decade is 8.5dB, in the 6th decade is 10.4dB, and in the 7th decade is 12.9dB. The older, the more is the difference. 4. After age adjustment, the number of workers diagnosed as NIHL decreases to 60% of unadjusted.

• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.274-281
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• 2015

Although noise-induced hearing loss (NIHL) is a significant public health problem, many people might not be aware that exposure to loud noise could occur hearing loss. The purpose of this study is to evaluate and analyze how importantly and seriously people are aware of NIHL using a 22-question survey. It was administered to random 150 people including between 20 s to 60 s. The questionnaire contained questions about i) views toward general health issues including hearing loss and tinnitus, ii) noise exposure, and iii) views toward hearing protection. Results showed that hearing loss was defined on a likert scale as 'a very big problem' by 17.33 % of respondents compared with other health issues. Surprisingly, most respondents (82 %) had not heard, read, or seen anything lately related to the issue of hearing loss. Many respondents had experience hearing problem or tinnitus under loud noise situations (85 %), however, only 11.33 % of respondents had used earplugs. Fortunately, many could be motivated to try ear protection if they were advised by a medical professional (80 %) or were aware of the potential for permeant hearing loss (78.67 %). We concluded that awareness of the potential for permanent hearing loss with noise and effective methods of hearing protection should be announced to public for preventing NIHL.

• Safety and Health at Work
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• v.6 no.2
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• pp.134-138
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• 2015

Background: Noise-induced hearing loss (NIHL) is a major preventable occupational health problem with 250 million people worldwide known to have disabling impairment of moderate to greater severity. The aims of the study are to estimate the prevalence of NIHL in the police force; and study its association with age, sex, duration of service (years), smoking and alcohol habits, use of hearing protective devices, as well as preexisting chronic diseases. Methods: A cross-sectional study was conducted on 543 police personnel who had undergone periodic medical examination over a 12-month period. The diagnostic criteria for NIHL were (1) history of occupational noise exposure, (2) bilateral hearing loss, (3) hearing loss of ${\geq}25dBA$ at 4,000 Hz in two consecutive audiograms, and (4) no significant medical history affecting hearing. Severity of NIHL was based on the World Health Organization grading. Results: Males (74.8%) made up the majority of the police force. The mean age for police personnel was $35.55{\pm}9.57years$, and the mean duration of service was $14.75{\pm}9.39years$. Compliance with the usage of hearing protective devices was seen in 64.4%. The prevalence of NIHL in this study population was 34.2%, with a higher prevalence in males (37.7%) than in females (23.9%). The study also showed strong associations between NIHL and male sex (odds ratio, 1.9; P < 0.05), and hypertension (odds ratio, 3.3; P < 0.001). Overall, 93% were found to have mild NIHL, 3.5% had moderate NIHL, and 3.5% had severe NIHL. No police personnel were found to have profound hearing loss. Conclusion: The prevalence of NIHL in this study is high compared to other similar studies among police personnel. This study shows that increasing age, male, presence of hypertension, diabetes, and longer duration of service are significant associated factors for NIHL. Preventative strategies include health surveillance, implementation of a hearing conservation program, and legislation.

• Journal of agricultural medicine and community health
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• v.15 no.2
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• pp.134-140
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• 1990

The causes of occupational hearing loss are physical trauma. ototxic substances and noise. However, only noise induced hearing loss of workers has been reported in Korea as second cause of occupational disease. We report a case of progressive hearing loss in worker exposed to noise. carbon disulfide and hydrogen sulfide for about 13 years. Because of his hearing loss he had to move another position where no noise and no ototoxic substance is. Following audiometry showed that his hearing loss had worsen than before.

• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.200-208
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• 2007

The noise induced hearing loss, which is one type of the hearing losses, is well known occupational diseases. The prevention of the noise induced hearing loss is very important, because it is unrecoverable. There are some kinds of devices for hearing protection, and those are effective in preventing the noise induced hearing loss. However, people often resist the use of hearing protection devices because they have some difficulties during conversation in wearing the devices. To solve the problem, a small acoustic filter can be used for a hearing protection device. In this paper, we designed several kinds of small acoustic filters and analyzed the characteristics of designed small acoustic filters using Finite Element Analysis (FEA). From FEA results, we proved the characteristics of designed small acoustic filters which vary according to length and diameter. And we found out that the general tendencies of modeled filters using FEA are same as acoustic experiment results of designed filters.

• Safety and Health at Work
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• v.11 no.2
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• pp.199-206
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• 2020

Background: In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar. Methods: A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss. Results: In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss. Conclusion: Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

• Safety and Health at Work
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• v.11 no.3
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• pp.249-261
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• 2020

Background: Hearing loss is one of the most prevalent worker health conditions worldwide. Although the effect of noise exposure on hearing is well researched, other workplace exposures may account for significant hearing loss. The aim of this review was to determine whether occupational hand-arm vibration exposure through use of power or pneumatic tools, independent of noise exposure, is associated with permanent hearing loss. Do workers suffer from hand-arm vibratione-induced hearing loss? Methods: Peer-reviewed articles published in English between 1981 and 2020 were identified through five online databases with five search keywords. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, including online database search methodology, study selection, article exclusion, and assessment of potential study design confounders and biases, were followed. Results: Database searches retrieved 697 articles. Fifteen articles that reported 17 studies met the criteria for review. All but two studies revealed statistically significant associations between occupational exposure to hand-arm vibration and hearing loss. The majority of the study results revealed associations between hand-arm vibration and hearing loss, independent of potential age and noise confounders. Conclusion: Few studies have examined the association between occupational exposure to hand-arm vibration and hearing loss. Dose response data were limited as only one study measured vibration intensity and duration. Although the majority of studies identified statistically significant associations, causal relationships could not be determined. Further research using standardized and uniform measurement protocols is needed to confirm whether the association between occupational exposure to hand-arm vibration and permanent hearing loss is causal and the mechanism(s).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.2
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• pp.94-101
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• 2010

This study was performed to examine the asymmetry of hearing loss among the noise exposed male workers. Findings of otoscopic examination, pure tone audiometry and tympanometry were evaluated for 179 male workers working in the noise exposed workplace. And also selfadministered structured questionnaires were used for each worker's work-related and general characteristics including personal health behaviors. There were significant differences of hearing threshold between right and left ears at 1,000 Hz and 3,000 Hz(p<0.05). And also significant differences of hearing threshold were noted in the age group over 50 at 3,000 Hz, the high risk drinking group either at 3,000 Hz and 4,000 Hz, the work duration group 10-19 years at 3,000 Hz, the noise exposure group under 90 dB(A) at 3,000 Hz, the noise exposure group over 90 dB(A) at 1,000 Hz, the non-wearing protective device group at 4,000 Hz, and the wearing protective device group at 3,000 Hz(p<0.05). Further study is needed to explore the extent and the related factors of the asymmetry of hearing loss in the general population and occupationally noise exposed group.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.47-55
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• 1999

Recently, noise from personal cassette players (PCP) poses growing concerns together with occupational noise-induced hearing loss. Eighteen male and female volunteer subjects participated to determine preferred noise levels for PCP usage before, during, and after 2-hour subway riding according to sources (types) of PCP listening (language/news, soft music, and hard music). Audiometric tests were conducted before and after the 2-hour exposure of PCP noise under subway riding. Statistical analyses showed some significant hearing losses with the greatest loss of more than 6 dB at 4000 Hz for both ears, indicating that serious noise-induced hearing loss would potentially occurred due to prolonged use of PCPs. Practical safety countermeasures against PCP noise are further discussed.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.336-341
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• 2010

One mechanism of inner ear damage by noise-induced hearing loss (NIHL) is the production of reactive oxygen species (ROS). Because Korean red ginseng (KRG) has an anti-ROS effect in various tissues, KRG may have a role in preventing NIHL. A window period exists in which ROS formations continue after noise exposure, and further damage can be prevented by antioxidants. In this study, we aimed to investigate the effects of KRG after exposure to noise. KRG (200 mg/kg) was fed to mice for 3 days after noise exposure. The change in hearing level was analyzed by measuring the auditory brainstem response. To induce a temporary threshold shift (TTS) of hearing, mice were exposed to 110 dB white noise for 3 hours. Fast recovery of hearing was observed in mice fed KRG 1 hour and 1 day after noise exposure for 3 days. The expression of 8-oxoguanine was not observed in the inner ears of mice fed KRG 1 hour after noise exposure, but was evident in the stria vascularis of mice in the control group (noise exposure only). From this study, we conclude that KRG acted as an effective inhibitor of NIHL in TTS cases.