• Journal of Preventive Medicine and Public Health
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• v.24 no.1 s.33
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• pp.86-92
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• 1991

To test if exposure history to rifle fire or cannonade training during military duty can induce hearing loss, history of personal military service and histroy of gunshot exposure were asked to 228 male college students with self -administrative questionnaire. Otoscopic examination and Rinne's test were performed if any abnormal finding was detected by pure-tone audiometry. Average hearing threshold levels of 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz and threshold levels at 4,000 Hz were calculated for 112 students who were remained after exclusion of cases with history of ear disease, of ototoxic drug administration, and of neuropsychiatric disease, and mean of those were compared between group of students who have completed military duty (completed group) and group of those who have not (not-completed group), and between group exposed (exposed group) and group unexposed to gunshot sound (unexposed group). Mean of average hearing threshold level and mean of threshold levels at 4,000 Hz of completed group and those of exposed group were higher than those of not-completed group and unexposed group, respectively. Proportion of cases that average threshold level was greater than 40 dB or threshold levels at 4,000 Hz was greater than 50 dB were higher also in completed group and exposed group than in duty not-completed group and unexposed group, respectively Multiple linear regression analysis including age, duration of military service, degree of gunshot sound exposure as independant variables and average hearing threshold level as dependant variable, was performed in order to estimate the effect of age on hearing, and any considerable effect of age on hearing could not be found. In conclusion, hearing impairment can be induced by rifle fire or cannonade training.

• Korean Journal of Family Medicine
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• v.39 no.6
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• pp.364-369
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• 2018

Background: Compared with other chronic diseases, hearing loss is generally overlooked from the perspective of disease burden. However, hearing loss is emerging as an important issue in the current society. The objective of this study was to investigate disease burdens and marginal utilities associated with hearing loss and other chronic diseases. Methods: This study analyzed the cross-sectional data of 32,986 participants aged 19 years and older who completed the Korea National Health and Nutrition Examination Surveys between 2009 and 2013. Additionally, this study used the pure tone audiometric test, European Quality of Life-Five Dimensions Questionnaire, and chronic disease status. The data were analyzed using a multiple linear regression method. Results: The data of 23,297 people who underwent a pure tone audiogram and completed the European Quality of Life-Five Dimensions Questionnaire were used in this analysis. The marginal utility of hearing loss ranked fifth among nine chronic diseases. The estimated loss of quality-adjusted life years associated with hearing loss was -93.69 years per 100,000 people, which is similar to other chronic diseases. Conclusion: This study assessed the marginal utilities and public burdens of hearing loss and eight chronic diseases in a South Korean population. Although the values may vary depending on country and race, this study may provide an indispensable foundation for more detailed studies on hearing loss.

• Journal of the Korean Professional Engineers Association
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• v.41 no.5
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• pp.65-69
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• 2008

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.57-63
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• 1984

To assess the hearing conservation by the hearing protection devices in the field, 1,237 healthy female weavers of 16 to 24 year old were surveyed from April 1982 to January 1983. By reviewing the charts, their working durations, hearing threshold shift levels and whether wearing the ear plugs or not were checked. The hearing threshold levels were measured at 4,000Hz by audiometry AA-30A, RION Japan. They were divided into two groups: an experimental group with ear plug and the control group without it. The threshold shift level above 40dB in controls was 44.6% in left and 40.9% in right ear and that in experimental group 8.0% in left and 6.6% in right ear. The distribution of threshold shift levels between control and experimental group was significantly different in both ears, but that between left and right ear not significantly different in both groups. The longer the working durations were, the more the proportion of high threshold shift levels was and the larger the differences in the proportion of above 40dB between both groups were.

• Journal of Preventive Medicine and Public Health
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• v.24 no.4 s.36
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• pp.496-506
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• 1991

A cross-sectional study was conducted to investigate the effect of long term noise exposure on blood pressure among steel mill workers. The workers participated in periodic medical examinations performed from August 27 to September 6 in 1990. Examined were 1,034 workers with high-level noise exposure(average $91.8{\pm}5.2dB(A)$) and 390 workers with low-level noise exposure(average $75.2{\pm}4.6dB(A)$). No significant difference was found in systolic or diastolic flood pressure between the two exposure groups. Prevalence of hypertension (${\geq}160mmHg\;systolic\;or{\geq}100mmHg\;diastolic$) was higher in a younger age group (${\leq}40$ years old) of high-level noise exposure than of low-level noise exposure. However, the difference was not statistically significant. Furthermore, in younger ages, prevalence of hypertension appeared to be higher in the hearing loss group (${\geq}25dB\;at\;1000Hz\;or{\geq}40dB$ at 4000Hz in at least one ear) than in the normal hearing group. From multiple regression analysis, hearing loss, body mass index, age, alcohol and family history of hypertension were proven to be predictors of diastolic blood Pressure (p<0.02). When regression was performed for each age group, hearing loss was a strong predictor of diastolic pressure in the younger age group (p<0.01).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.298-309
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• 2019

Objectives: This study aimed to investigate stages of safety and health culture change through a reflection on 40 years of hearing conservation history at a multinational company. Methods: The target workplaces were multinational companies with more than 1,000 employees. The research used the clinical case study and system analysis methods based on direct observation of the research from 1994 to 2009. The latter method performed an analysis of the equilibrium state of the cross-section in the given period and the longitudinal profile of the change during the given period. Results: The stages of cultural change are divided into five stages and summarized as follows. In the first stage, workplace noise was not widely recognized as a hazard, while in the second stage, the measurement of noise levels and audiometric testing were conducted under the Korean Occupational Safety and Health Act (KOSHA). The driving force for change in the second stage was the amendment of the KOSHA. In the third stage, noise came to be recognized as a hazard factor through awareness training. The driving force of change during the third stage was the strong executive power exerted by the audit of the industrial hygiene program from the US head office. In the fourth step, there was a change to actually reduce noise. The driving force in this stage was a change in company executives' risk perception resulting from lawsuits over noise-induced hearing loss and the task force team activities for culture change based on the action learning protocol. At the fifth stage, a 'buy quiet policy' was institutionalized. The management's experience that noise reduction was difficult was the motivation to manage noise from the time of purchase of equipment. Conclusions: The activities of a hearing conservation program are determined by the improvement of the legal system and by the way it is enforced. Noise control activities to reduce noise areas may be possible through the shared risk perception of noise-induced hearing loss and by a change agent role as a facilitator to implement noise control.

• Journal of Preventive Medicine and Public Health
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• v.22 no.3 s.27
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• pp.337-354
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• 1989

In order to evaluate the noisy environment and hearing loss of workers served in noisy working environment, the author investigated 212 manufacturing industries located in Ulsan Industrial District that could be observed for 3 successive years from 1986 to 1988. The obtained results were as follows: 1. There was increased tendency in the number of workers served in noisy working environment and that of examined of hearing loss for three years. 2. In the noise level of working environment, the number of industries less than 89dB(A) was increased every year, while more than 90dB(A) was in decreasing tendency. 3. Mean hearing loss by frequency was the most prominent in 4,000Hz, the level of hearing loss was in increasing tendency yearly, and that of left eat was higher than right ear in almost all type of industry. 4. In 1986, the level of hearing loss by type of industry was highest in manufacture of electric and electronic, and followed by paper and plywood, and metal products in right ear: that was in the order of manufacture of electric and electronic, metal products and textile products in left ear. In 1987, that was in the order of manufacture of metal products, machinery and others in right ear, and metal products, machinery and food stuff in left ear in 1988, manufacture of others, food stuff and machinery in both ear. 5. In hearing loss by service duration, right ear of 5-9 years group was higher than that of less than 5 years in 1987, whereas in 1988, the longer in service duration, the higher in the level of hearing loss in both ear. 6. In 1986, 1987 and 1988, the prevalence rate of noise-induced hearing loss were showed increasing tendency as 0.4% ,0.8% and 1.5% , respectively, and manufacture of textile products was highest(1.0%) in 1986, machinery(1.2%) in 1987 and others(2.8%) in 1988. 7. The proportion of grade E in early loss index were 76.1% (1986), 78.2% (1987) and 80.5% (1988) in left ear, 75.9% (1986), 76.4% (1987) and 75.9% (1988) in right ear.

• Journal of Korea Multimedia Society
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• v.21 no.2
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• pp.261-270
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• 2018

Hearing-impaired people are increasing rapidly due to the global aging trend. Early detection of hearing loss requires an easy-to-use audiometry device for the public. Existing audiometry systems were developed as PC-based, PDA-based, or smartphone apps. These devices were often dependent on specific software platforms and hardware platforms. In this paper, we tried to improve software platform compatibility by using cross platform, and tried to implement IoT-based pure tone audiometry device which does not require sound pressure level correction due to hardware differences. Pure tone audiometry is available in a variety of ways depending on the type of hearing loss and age. Using the IoT-based audiometry device implemented in this paper, it will be possible for an app developer who lacks hardware knowledge to easily develop an app with various scenarios for hearing screening. The results of this study will contribute to overcoming the software and hardware dependency in the development of IoT-based healthcare device.

• Safety and Health at Work
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• v.8 no.4
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• pp.364-370
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• 2017

Background: Labeled noise reduction (NR) data presented by manufacturers are considered one of the main challenging issues for occupational experts in employing hearing protection devices (HPDs). This study aimed to determine the actual NR data of typical HPDs using the objective fit testing method with a microphone in real ear (MIRE) method. Methods: Five available commercially earmuff protectors were investigated in 30 workers exposed to reference noise source according to the standard method, ISO 11904-1. Personal attenuation rating (PAR) of the earmuffs was measured based on the MIRE method using a noise dosimeter (SVANTEK, model SV102). Results: The results showed that means of PAR of the earmuffs are from 49% to 86% of the nominal NR rating. The PAR values of earmuffs when a typical eyewear was worn differed statistically (p < 0.05). It is revealed that a typical safety eyewear can reduce the mean of the PAR value by approximately 2.5 dB. The results also showed that measurements based on the MIRE method resulted in low variability. The variability in NR values between individuals, within individuals, and within earmuffs was not the statistically significant (p > 0.05). Conclusion: This study could provide local individual fit data. Ergonomic aspects of the earmuffs and different levels of users experience and awareness can be considered the main factors affecting individual fitting compared with the laboratory condition for acquiring the labeled NR data. Based on the obtained fit testing results, the field application of MIRE can be employed for complementary studies in real workstations while workers perform their regular work duties.

• 대한예방의학회:학술대회논문집
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• 1998.10b
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• pp.64-65
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• 1998