• Journal of Preventive Medicine and Public Health
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• v.5 no.1
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• pp.115-123
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• 1972

As a link of chain study program of school health, a survey was made up by the screening test with audiometry for hearing disturbance on 18,675 high school students who are mainly aged in 15-19 years from November 5.1969 to October 30. 1970. The results obtained were summerized as follows. According to our criteria as table 3, the rates of the profound, the severe and the moderate who required the appropriate hearing aids were 0.02%, 0.03% and 0.14% respectively:-the cumulative percentage was 0.197. When the marginal, 0.23% should be included the cumulative rate was 0.41%. But there was no-significance by sex and school classes. If we will make the special classes for them one class would be estimated out of 10,000 persons when a class is formed with about 15 persons. Otherwise when we examined that according to each ear of persons, the rates of the profound, the severe and the moderate were 0.17%, 0.22% and 0.33% respectively and their cumulative percentage wag 0.72. There was no significance also by sex and age. By the way, the rate of hearing disturbance in urban high school students tended to lower than rural. And the perceptive disturbance was higher than rural in rate. The conductive disturbance tended to oppose in comparison with the above.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.4-5
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• 1979

The degree of hearing impairment of chronic otitis media will indicate the nature and severity of middle ear pathology especially condition of ossicular chain, size of ear drum perforation and location of granulation tissue in the middle ear cavity. The subjects were 189 ears of tympanoplasty for chronic otitis media and divided into four groups as follows: Normal ossicular chain with only ear drum perforation (group I), normal ossicular chain with granulation tissue only around the ossicles regardless of any other region (group II), ossicular ankylosis or fixation of handle of malleus to promontory with or without granulation tissue around the ossicle (group III) and ossicular interruption by partial or complete destruction(groupf IV). The results were concluded as follows: 1) The average hearing threshold of chronic otitis media was 44.6 dB and hearing threshold was closely related to the condition of ossicular chain. Hearing threshold became greater in order of normal ossicular chain, ankylosis and interruption. 2) The average hearing threshold of ossicular interrupted group was 49.1 dB and it was greater in the cases of total destruction than that of partial destruction. 3) The hearing loss in the cases of normal ossicular chain with only tympanic membrane perforation was within 45 dB and this level was presumed to represent normal ossicular function. The degree of hearing loss was in proportion to the size of ear drum perforation and when over 45 dB, other middle ear pathology was suggested. 4) In the cases of small ear drum perforation with normal ossicular function, the hearing threshold was within 30 dB. 5) In the type of audiogram, flat type was 30.2% and ascending type 35.4%. Descending type was more frequent in the cases of normal ossicular mobility with granulation tissue around the ossicle and flat type was observed frequently in the cases of ossicular ankylosis. 6) Carhart's notch was seen in 14 cases (7.4%) and observed mainly in ossicular ankylosis. 7) There was no relation between hearing threshold and histopathological type of granulation tissue in chronic otitis media. However the degree of hearing impairment was related to the location of granulation tissue in the middle ear cavity. 8) Authors recognized the granulation tissue compensated the function of interrupted ossicular chain.

• 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).

• Proceedings of the KOR-BRONCHOESO Conference
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• 1987.05a
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• pp.5.1-5
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• 1987

Cisplatin (cis-dichlorodiamine platinum II)은 두경부 및 고환의 악성종양에 아주 효과적이라고 알려져 있다. 그러나 이 약물은 이독성 및 신독성이 이미 임상연구로 발표되어 있으며 신독성은 cisplatin 투여시 이뇨제 및 수액의 투여로 그 정도 및 빈도는 감소시킬 수 있지만 이독성은 감소시키지 못한다. Cisplatin에 의한 이독성은 보통 자각적으로 나타나지 않는데 이는 내이 와우각의 회전중 저부에서 일어나며 또한 외유모세포의 최외측열에서 일어난다고 동물실험에서 밝혀진 바 있다. 본 교실에서는 cisplatin의 이독성을 관찰하기 위하여 1회에 cisplatin 60~80 mg/$m^2$을 투여한 두경부 악성종양환자를 대상으로 투여전후의 청력을 비교 관찰하였다. 1) 청력은 대부분 10㏈ 이내의 손실례가 많았다. 2) 최대청력손실이 있는 주파수는 8KHz, 4KHz의 순으로 주로 고음역에서 발생하였다. 3) 신독성은 전례에서 관찰되지 않았다.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.186-192
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• 2012

Noise is a major cause of hearing loss in the air base. There are lots of risk factors of hearing loss including noise, and hearing loss can be accelerated by combined effects of these risk factors. Here in, we reviewed risk factors of hearing loss, and analysed key risk factors inducing hearing loss in the air base. Risk factors exacerbating hearing loss with noise were mainly investigated in this research because noise could not be an avoidable risk factor in the air base. Analysed data will contribute to make green environment minimizing hearing loss of pilots and supporting personnels in the air base.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.234-236
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• 2009

종래의 음향기기에서 소리 크기는 각 주파수별로 다른 감도를 갖는 개인의 주파수 청력 특성을 고려하지 않고 모든 주파수에 대하여 동일하게 선형으로 소리 크기를 조절한다. 따라서 감도가 높은 주파수대에서 청력 손상을 일으킨다. 이를 개선하기 위한 표준 청력특성, ISO266:2003 표준을 이용한 평활화 방법이 있지만, 이 표준에 따른 등청감곡선은 여러 사람에 대해 평균한 청력특성이기 때문에 다양한 환경에 의해 변형된 개인별 청력특성에 맞지 않아 청력 손상을 감소시키는 실질적인 효과가 저하되는 문제점이 있다. 본 연구는 사람마다 다른 최소가청한계 특성을 갖는 청각특성과 최대가청한계를 고려하여 소리 크기를 조절함으로써 음향기기에 의한 청각 손상을 감소시키는 방법에 관한 것이다. 컴퓨터 시뮬레이션을 통해 청력 특성이 좋은 대역에서 기존 방법에 비해 보다 낮은 소리 크기에서 불편없이 인지 가능하다는 것을 확인할 수 있었으며, 동시에 과도한 대역별 소리 에너지를 줄여 청각 손상도 방지할 수 있다는 것을 확인할 수 있었다.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1987.05a
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• pp.10.2-10
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• 1987

최근 사회구조의 발달로 우리주변에는 뜻하지 않은 청력장애를 일으키는 경우가 많고 의료보험 실시와 더불어 생활수준의 향상으로 이비인후과 외래를 찾는 청력장애자들이 많아지고 있다. 또한 청력장애를 호소하여 청각검사를 의뢰하는 타과 입원환자도 점차적으로 증가하고 있는 실정이다. 이에 저자들은 1985년 1월 1일부터 1986년 12월 31일까지 만2 년간 연세대학교 원주의과대학부속 원주기독병원 이비인후과로 의뢰된 타과 입원환자 1063예중 청각검사를 시행한 182예를 대상으로 임상청각학적 고찰을 하여 다음과 같은 결과를 얻었다. 1) 의뢰한 과별로는 신경외과(50.5%)가 제일 많았고 다음 내과(23.6%)의 순이었다. 2) 원래질환과 청력장애사이에 연관관계가 있는 경우는 102예 (56.0%)이었으며 이중 외상이 87예(86.2%)로 제일 많았다. 3)외상의 경우 폭발사고가 35예 (40.2%)로 제일 많았고 다음 교통사고 28예(32.1%)의 순이었다. 이 중 계속적인 추적치료를 시행한 경우가 9예 (10.3%)에 불과하였다. 4) 외상의 경우 청력손실의 형태별로는 전음성이 41예 (47.1%), 감음신경성이 30예(34.4%), 혼합성이 7예 (8.2%) 였으며, 사병자(malingerer)가 9예 (10.3%) 였다. 결론적으로 강원도의 지역적 특성상 탄광폭발 사고로 인한 외상후 이차적으로 청력손실을 호소하는 환자가 많은 편으로 이에 대한 적극적인 진단 및 추적치료를 위하여 특히 신경외과와 상호협조 체제가 필요할 것으로 사료된다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.454-455
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• 2005

• 대한예방의학회:학술대회논문집
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• 1993.10a
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• pp.117-118
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• 1993

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.30-39
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• 1999

Objectives. This study was carried out to evaluate hearing impairment judgement and to investigate the differences in various diagnostic criteria for noise-induced hearing loss (NIHL) among workers who required for close observation (C). Methods. Out of 731,029 workers who had taken the specific periodic health examination in 1994, we used the audiometric data on 37,999 workers (C) eliminating the employees who had previous otologic problems. Many investigators have being using different criteria for the evaluation of hearing impairment. In this study, we used the criteria of early (1989-1994), current, compensation for NIHL in Korea, 2-, 3-, 4-divided classification and hearing loss at 4,000 Hz and compared the evaluation results. Results. The prevalences of C and workers who had occupational disease $(D_1)$ diagnosed for NIHL were 11.1 % and 0.44 %. There were significant difference in the prevalences of C and $D_1$, depending on different province of Korea. Pure tone averages (PTAs) were not appropriately applied in their evaluation 97% of workers whom we studied on were below the level of mild hearing loss judged by ISO standard. However, there were wide variations in the prevalence rate of mild hearing loss by diagnostic criteria. Thus, there were different judgements in determining the degree of NIHL depending on which diagnostic criteria were utilized. PTAs were found 20.54 (Rt) and 20.74 (Lt) when the method of 3-divided classification was applied for audiometric data. The degree of hearing impairment of the left ear was more severe than that of right ear. The prevalence of normal hearing threshold below 20 dB was 75.4% and the range of difference in both ear was below 10 dB. Right sided hearing threshold levels were 21.08 dB (500 Hz), 18.44 dB (1,000 Hz), 22.09 (2,000 Hz) and 52.36 dB (4,000 Hz). There was typical high frequency loss (C5-dip at 4,000 Hz) above 30 - 40 dB in normal hearing level. The increasing trend in hearing threshold level was gradually decreased by the increase of PTAs. The difference between PTAs and threshold at 4,000 Hz was about 10 dB. Conclusions. We could found that PTAs in the previous examination were not appropriately evaluated. This study revealed that they did not use unique criteria for managing the workers of NIHL. For the prevention of NIHL, it was found that the quality control on diagnosis and comprehensive management program were required, especially for those of hearing loss (C).