• 센서학회지
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• 제13권6호
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• pp.479-487
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• 2004

The prevention of noise induced hearing loss is very important, because there is no treatment for it. There are some kinds of devices for hearing protection, and those are effective in preventing a noise induced hearing loss. However, people often resist the use of hearing protection devices because it is difficult to have a conversation. Therefore, a hearing protection device is must effective not only in hearing protection but also in preserving communication ability. In this paper, we proposed a small acoustic filter for ITE type noise protector to solving the problem about the difficulties of conversation. That is applied a principle of acoustic filters that have been used for a muffler of automobiles, guns, and etc. To find out the sound transmission characteristic at the eardrum, we regarded an acoustic filter and external ear canal as a coupled system. So, we simulated the coupled system with OrCad, and experimented with a designed acoustic filter and a 2 cc coupler which has the same transmission characteristic as the external ear canal has. We confirmed that it is possible to adjustment acoustic transmission characteristics through simulation of electrical model for acoustic filter and external ear and experiments using designed small acoustic filters.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1976년도 제10차 학술대회연제 순서 및 초록
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• pp.85.1-85
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• 1976

103~105㏈의 소음강도를 갖인 방직공장의 직포장에서 근무하고 있는 18세에서 25세까지 184명 (351이)의 여자공원를 대상으로 근무연한을 1년이하, 1~2년, 2~3년, 3~4년 4년이상 군인 5개 군으로 세분하여 청력검사를 실시한 결과 몇 가지 결론을 얻었다. 1. 총대상 인원 184명 (351이) 중에서 73명 (129이)이 소음성 난청을 보여 소음성 난청의 출현율은39.7%(36.8%)으며 1년이하 근무군에서는 29.2%의 출현율을 보였으나 1~2년 근무군에서 급격히 증가하여 그 후에는 큰 변화가 없었다. 2. 순음 청력역치에서 4,000Hz에 40㏈ 정도의 가장 큰 청력손실을 보이며 근무연한에 따라 약간 증가하는 경향을 보이나 최초 1년 동안에 가장 청력손실이 심히 발생하였고 그 후에는 별 변화가 없었다. 3. 고주파수 (3,000, 4,000, 6,000Hz)에서의 평균 청력치는 근무연한에 따라 증가하는 경향을 보이나 역시 최초 1년 동안의 청력손실이 가장 심하였으며 그 후 변화가 없었다. 그러나 8,000Hz에서의 평균청력치는 근무연한에 따라 증가하는 경향을 보였다. 4. 저 주파수(500, 1,000, 2,000Hz)에서의 청역의 평균역치는 정상 청역범위이내였으며 근무연한수에 따른 어떤 변화를 보이지 안하였지만 2,000Hz 한 주파수에서는 25㏈이상의 청력손실을 보인 이는 35이로 27.1%였다. 5. 4,000Hz에서 최대 청력손실을 보인 예는 94이(72.7%)로 대부분을 차지하였으며 4,000Hz의 주위 주파수(3,000, 6,000, 8,000Hz)에서 최대 청력손실을 보인 예는 근무년한의 증가에 따라 약간씩 증가하는 경향을 보였다. 즉 근무년수의 증가에 따라 고주파에서 청력손실을 초래하여 dip 현상이 점차 소멸되여 가는 것을 볼 수 있었다. 결국 103~105㏈ 소음에 노출되었을 경우 최초 1~2년 동안에 급격한 소음성 난청을 초래하며 그 후 5년까지는 완만히 진행되는 경향을 보이고 있다.

• International Journal of Advanced Culture Technology
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• 제7권2호
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• pp.218-226
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• 2019

In modern society, people live in an environment with artificial or natural noise. Especially, the sound that corresponds to the artificial noise makes the noise itself and affects each other because many people live and work in the city. Sounds are generated by the activities and causes of various people, such as construction sites, aircraft, production machinery, or road traffic. These sounds are essential elements in human life and are recognized and judged by human auditory organs. Noise is a sound that you do not want to hear by subjective evaluation, and it is a loud sound that gives hearing damage or a sound that causes physical and mental harm. In this study, we introduce the method of stimulating the human hearing by finger vibration and explain the advantages of the proposed method in various kinds of a noise environment. And how to improve the sound quality to improve efficiency. In this paper, we propose a method to prevent the loss of hearing loss and the transmission of sound information based on proper signal to noise ratio when using portable IT equipment in various noise environments.

• Safety and Health at Work
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• 제15권2호
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• pp.181-186
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• 2024

Background: This study aimed to analyze the trend of occupational noise-induced hearing loss (ONIHL) in Brazilian workers at a metallurgical plant with a hearing conservation program (HCP), which has been addressed in a previous study. Methods: All 152 workers in this time series (20032018) participated in the HCP and used personal protective equipment. All annual audiometry records in the company's software were collected from the electronic database. The trend of ONIHL was analyzed with the joinpoint regression model. The hearing thresholds of ONIHL cases at the end of the series were compared with those found in a national reference study. Results: The binaural mean hearing thresholds at 3, 4, and 6 kHz at the end of the series were higher for ages ≥50 years, exposures ≥85 dB (A), time since admission >20 years, and maintenance workers. Significance was found only in the group divided by age. There was an increasing time trend of ONIHL, though with a low percentage variation for the period (AAPC = 3.5%; p = 0.01). Hearing thresholds in this study differed from the reference one. Conclusion: Despite the unmet expectation of a stationary trend in the study period, the time pace of ONIHL evolution did not follow what was expected for a population exposed to noise. These findings signal to the scientific community and public authorities that good ONIHL control is possible when HCP is well implemented.

• Journal of Preventive Medicine and Public Health
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• 제27권2호
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• pp.286-298
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• 1994

For the purpose of presenting the basic data for the establishment of control measures on the long-term noise exposed workers, this study was carried out on the relationship between personal noise exposed dose and hearing loss on the 67 male workers whose hearing threshold had exceeded 40 dB in 4,000 Hz, from 1990 to 1992. Conclusively, the level of hearing loss was significantly related to personal noise exposed dose in follow-up period. We considered that personal noise exposed dose which was measured by the personal noise dosemeter was more efficient rather than the noise level of workplace for the evaluating the long-term change of hearing acuity. And although in the case of not-diagnosed as noise induced hearing loss. it was suspected that the active control programs such as improvement of noisy environment or early transfer to proper workplace were needed on the workers who exposed with over 90 dB in personal noise exposed dose.

• 한국학교ㆍ지역보건교육학회지
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• 제14권2호
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• pp.93-112
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• 2013

Objectives: This study was conducted to investigate the incidence rate of noise-induced hearing loss (NIHL) in Korean youths using the National Health Insurance Data Methods: We obtained the case of NIHL with the National Health Insurance Data and calculated the incidence rate of NIHL after classifying them by year (from 2005 through 2008), age, gender, birth cohort. Results: The age-adjusted incidence rate by year of NIHL per 100,000 population increased by 40.6% from 13.8 persons in 2005 to 19.4 persons in 2008, which showed a increasing trend every year. In particular, the incidence rate per 100,000 population among the adolescents (15-19 years of age) shot up by 78.2% from 8.7 persons in 2005 to 15.5 persons in 2008. According to the incidence rate by birth cohort of NIHL, the birth cohorts showed the gradually increase in incidence rate as time passed by. Adolescents in early 20s (20-24 years of age) had a higher incidence rate than teenage and men had a higher incidence rate than women. Conclusions: The results suggest that incidence rate of NIHL in Korean youths has rapidly increased among adolescents. Therefore, it is required to educate adolescents about the risk of hearing loss due to noise, establish program to prevent NIHL among adolescents and provide them with health education on hearing loss prevention.

• 한국음향학회지
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• 제30권4호
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• pp.207-214
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• 2011

사람의 청력은 노화로 인해 자연스럽게 저하된다. 하지만 최근 들어 젊은 나이에 난청이 발생하는 경우가 크게 늘고 있다. 이처럼 난청인구가 증가하는 가장 큰 이유는 각종 휴대용 멀티미디어 기기의 대중화에 기인한다. 현재 이어폰/헤드폰으로 유발되는 소음성 난청 연구는 많이 이루어지고 있으나, 직접적인 휴대전화 통화에 따른 소음성 난청유발에 대한 연구는 거의 없다. 본 연구에서는 선행 조사를 토대로, 골전도 스피커에 Active Noise Reduction기술을 접목하여 소음성 난청을 예방하는 기술을 제안한다. 이 기술은 주변소음을 골전도 스피커를 통해서 능동적으로 역위상 진동을 부과하여 노이즈를 줄이는 방법이다. 제안한 시스템을 적용할 경우 실제 청각에 유입되는 소음레벨이 12 dB 이상 감소되며, 이러한 음량 감소폭은 휴대폰 통화에 따른 소음성난청 요인을 근본적으로 예방하는 것이다. 감성실험 결과 통화음량이 감소된 상황에서도 원활한 통화가 가능하였다.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.371-386
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• 1993

This study was carried out to evaluate diagnostic criteria of noise-induced hearing loss (NIHL) among-workers in an iron foundry. Of 1,093 workers under the observation of noise-specific health examination, 184 workers were selected by way of first and second screening audiometric examination. A questionnaire survey, otological examinations, Rinne test and audiometric test were performed and the results were as follows ; The degree of hearing impairment in the left ear was more severe than in the right ear (p<0.05). The difference between hearing threshold of the first and the second hearing test at 1,000 Hz was about 5 dB with a narrow range of deviations while the difference at 4,000 Hz was about -7 dB with a wide range. Of the total study workers, 84.8% were tested within 15 hours away from noise exposure, and the rest after 16 hours. This study has identified that mean hearing loss at 4,000 Hz showed a significant statistical difference among the two study groups while mean hearing loss by 4-divided classification did not. The same phenomena were observed between the group with and without tinnitus and between the group with and without difficulty in hearing (p<0.05). Among 184 workers, 10 workers (5.4%) diagnosed as NIHL by old diagnostic criteria in contrast to 150 workers diagnosed as NIHL by the new diagnostic criteria. There was a significant difference between the two groups in the average hearing loss at 4,000 Hz and 4-divided classification (p<0.01), but there were no significant differences in age, the duration of employment, blood pressure and the duration wearing the personal hearing protector (p>0.05). If we apply Early Loss Index (ELI) method, some workers in younger age group diagnosed as NIHL by the new diagnostic criteria were fallen into within the normal range. In the mean time older age group show reverse results in contrast to the above finding. It is too early to confirm the value of the usage of the new diagnostic criteria in hearing examination. Further study is called for to verify the value of this criteria.

• 한국안전학회지
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• 제34권4호
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• pp.95-102
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• 2019

The purpose of this study is to investigate the correlation between aluminum form work and noise-induced deafness by conducting special health examination on construction aluminum worker and noise measurement at the workplace. All the 11 aluminum form workers were diagnosed with noise-induced deafness after holding a special health examination. The workers have not had any previous history of noise-induced deafness which indicates that aluminum form work is related to noise-induced deafness disease. The impact noise of 120 dB(A)~125 dB(A), which exceeds the regulations of industrial safety and health act, was found during the dismantling rather than installation when noise measurement was made at the aluminum workplace. The aluminum form workers could permanently lose the hearing sense if they are exposed to this impact noise. This study is to suggest the method to prevent noise-induced deafness for aluminum form workers by firstly giving out hearing protection equipment at the construction site and secondly installing rubber mat, soundproof panel as well as changing the noise-lowering technique.

• Safety and Health at Work
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• 제2권4호
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• pp.336-347
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• 2011

Objectives: In Korea, an average of 258 workers claim compensation for their noise-induced hearing loss (NIHL) on an annual basis. Indeed, hearing disorder ranks first in the number of diagnoses made by occupational medical check-ups. Against this backdrop, this study analyzed the impact of 19 types of noise-generating machines and equipment on the sound pressure levels in workplaces and NIHL occurrence based on a 2009 national survey on work environments. Methods: Through this analysis, a series of statistical models were built to determine posterior probabilities for each worksite with an aim to present risk ratings for noise levels at work. Results: It was found that air compressors and grinding machines came in first and second, respectively in the number of installed noise-generating machines and equipment. However, there was no direct relationship between workplace noise and NIHL among workers since noise-control equipment and protective gear had been in place. By building a logistic regression model and neural network, statistical models were set to identify the influence of the noise-generating machines and equipment on workplace noise levels and NIHL occurrence. Conclusion: This study offered NIHL prevention measures which are fit for the worksites in each risk grade.