• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.83-86
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• 2005

The aim of this study is to establish the indoor noise limits of apartment houses for mad traffic noise. To achieve this goal, psycho-acoustic experiments were carried out with the mad traffic sound sources modulated by the transmission loss characteristics of the external windows. As a result of this study, followings are suggested. 1) On correlation between dose level and psycho-acoustical response, the initial level of negative feeling is located on $40.1{\sim}40.6$ Leq dB(A). 2) On the degree of satisfaction to road traffic noise, near 35% Point being same dissatisfaction degree is to be assumed $40{\sim}41$ dB(A) of indoor noise level presented into three vocabulary. It is suggested to be reasonable level of 40 dB(A) on the indoor noise limits for intruding road traffic noise, and it is appropriate to be the 5dB level difference between grades.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.154-157
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• 2005

Generally, noise from a indoor air conditioner has been measured by overall sound pressure level, dB. Customers evaluation, however, of the noise from an air conditioners should not be depend on the only overall level but also the sensory feeling. Moreover, in this sensory evaluation, irregular, time-varying and uneven sounds which are difficult to describe itself by overall level are more affectable. Unfortunately however the formal evaluation method for this kinds of noise is not determined yet. In this research, the evaluation method for tonal noise, which is one of the unmeasurable sounds by overall level, is proposed to evaluate its acceptability based on the consumer's sense of hearing. To consider the consumer's sense, several times of Jury evaluation are carried out. The proposed approach could be applied to the other sound, which acoustical characteristics are similar to the tonal noise .

• 한국소음진동공학회논문집
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• 제11권4호
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• pp.58-64
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• 2001

Sound absorbing materials are applied to the exposed surfaces of curvet subway tunnel for the reduction of curving noise level. Before the treatment, acoustical engineering simulation is performed to predict the noise level reduction for different kinds and amounts of absorbing material. The principle of geometrical acoustics is utilized to perform the simulation efficiently and accurately. The noise bevels of the inside and outside of running car body are measured to find the noise level reduction. The average noise level reduction of 8 dB has been attained. It has been shown that the simulated results are comparable to the measured ones.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2003년도 정기총회 및 추계학술대회
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• pp.95-100
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• 2003

The purpose of this study is to evaluate the noise environment of one-room type multi-family housing around the campus. The field measurements on equivalent noise level of indoor and outdoor were carried out in 6 subject house units during the 26th${\sim}$28th of November 2002. The results are as follows. 1) Outdoor noise levels of 6 subject buildings were distributed 52.8${\sim}$65.3dB(A) and were inappropriate to the standard for environmental noise, 55dB(A). 2) Indoor noise level of 6 subject house units were measured 27.5${\sim}$63.5dB(A). These values were higher than the indoor noise standard (40dB(A)) except subject house D(average 37.6dB(A)). 3) It was found that the differences of indoor noise levels between subject house units were caused by resident's living factor, characteristics of window, and existence of balcony.

• KIEAE Journal
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• 제9권1호
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• pp.61-68
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• 2009

In this study, computer simulation program was using to identify the effects of road traffic noise propagation depending on the road types which are very variable in dense city. To achieve this goal, the roads should adjacent to housing complex were categorized into 7 types and propagation noise level should predicted then after simulation of noise exposure population calculation are carried out. Followings the results. First, the road types producing the higher noise level are R1, R2, R3 and R7. The lowest one is R6. And R4, R5 showed that some amount of noise level reduction. Second. the R6 road type which is tunnel shaped showed the highest noise level reduction in vertical distance gap. Last, the order of noise exposure population ratio is R1>R2>R7 and R6 showed the lowest.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.11-16
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• 2006

It appraises that use an indoor noise standard, a NC value which is a noise appraisal, a dB(A) value, a N value in foreign country because it doesn't yet ready an appraisal standard in domestic. Also, It appraises that the supply and drainage noise which could change water supply pressure, $4kg/cm^2,\;3kg/cm^2,\;2kg/cm^2,\;1.5kg/cm^2,\;1kg/cm^2$, bring about a noise and inquires how does noise level indicates according to each instruments. In case of a water supply pressure standard, $3kg/cm^2$, a C-605is $3{\sim}5dB(A)$ lower than another instruments in directly overhead stories. It appears that all of them is similar to level in directly under level except c-407(2)Analyzed the NC value, c-605is the lowest level, NC-50, of a water supply pressure, $4.0kg/cm^2$, c-407 is the highest level, NC-55.(3) In case of N value, which is one of water supply methods in Japan, it is the lowest level, N-55, of a water supply pressure, $4.0kg/cm^2$ same as NC value and C-407is the highest level, N-60.(4) In case of water supply that is likely to noise level, It appears 6dB(A) level gap each instruments, and C-605 is the lowest level, 63.9dB(A).

• 대한소아치과학회지
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• 제47권1호
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• pp.62-69
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• 2020

이 연구는 치과 핸드피스의 소음 수준과 소음 저감 장치의 효과를 평가하기 위한 것이다. 귀 모형은 치과용 핸드피스 작동 중에 내이에 전달되는 소음의 수준을 측정할 수 있도록 설계되었다. 소음의 크기는 귀 모형과 휴대용 소음 측정기를 사용하여 다양한 조건에서 측정되었다. 시판되는 4종의 소음 저감 장치를 귀 모형에 적용한 후 같은 조건에서 소음 수준을 측정한 뒤 비교하였다. 치과 핸드피스의 소음 수준은 조건에 따라 약 82.5 - 84.4 dB이었다. 4종의 소음 저감 장치를 적용했을 때 소음은 67.4 - 73.8 dB로 감소했다. 4종의 장치 모두 핸드피스의 소음을 줄이는데 유의한 효과가 있었다. 강도와 노출 시간을 고려할 때, 치과 소음은 치과 의료진에게 청력 손상을 일으킬 수 있다. 직업적 청력 손상 위험을 예방하기 위해 소음 저감 장치 사용을 고려할 수 있다.

• 한국소음진동공학회논문집
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• 제26권5호
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• pp.616-624
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• 2016

Design of shelter system requires consideration of noise at operators’ positions, because noise can injure person’s health. That is why studies which analyze and predict noise at operator’s positions is essential. To analyze noise sources of shelter system, this study measured noise of each equipment and obtained new equations by comparing the measured noise data and the equation which is relation noise and distance. The new equations predict noise level at operators’ positions. Actran analysis is performed to obtain noise level at operators’ positions too. At last, the noise level at operators’ positions measured in real shelter system is compared with the noise level predicted the new equations and Actran analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.363-366
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• 2005

Social survey and auditory experiment on residential noises such as floor impact, air-bome, bathroom, drainage and traffic noises were conducted to investigate the effects of sensitivity and background noise levels on subjective response to residential noises. Results of survey showed that multiple questions for sensitivity to noise have a more power for discrimination against subjective response to noise than single question. It was also found that the correlation between sensitivity and annoyance was relatively low, but the differences in annoyance between sensitivity groups were significant. Result of auditory experiment showed that effects of sensitivity on annoyance were different according to noise type and noise level. It was also shown that the difference in annoyance between the lowest sensitive stoup and the highest sensitive group was significant in low noise level. The effects of background noise on subjective responses to noise was also different according to noise source and noise level, and were significant in low noise level of airborne and drainage noise.

• 한국조경학회지
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• 제26권3호
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• pp.19-33
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• 1998

The primary objective of this research was to develop optimal models for masking the road traffic noise with the sound of a waterfall at urban small green spaces. Noise levels were measured at 8 roadside green spaces in SEOUL and questionnaires were randomly distributed to 40 users for evaluating the noise at each site at the same time. College students participated in the experiment for the development of masking models and the developed models were tested by users at 2 green spaces. The major results are as follows ; 1. Traffic noises ranged from 65dBto 70 dB. Users' satisfaction with the noise became considerably low on the basis of 60 dB and it was highly related to noise level. 2. Noise was a main factor to depreciate the amenity of green spaces where its level was more than 60 dB and so it neds to be excluded or reduced the traffic noise at the process of design. 3. Masking effects kept constant independent of the spatial location of masker on condition that masker levels were equal. It was effective when masker was 5-10dB greater than noise level which was masked. 4. As noise level went up, satisfaction ratings about the masked noise became low but masking effects increased in proportion to its level. 5. It was proved that the models were valid through the field experiment.