• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.2
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• pp.181-191
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• 1991

The present study determined the overall noise level and the distribution of sound pressure level over audible frequency range of noise produced at various work sites. Work-related noise greater than 80dBA produced from 98 separate work sites at 37 manufacturing companies and machine shops were analysed for the overall sound level (dBA) and frequency distribution. In addition, to determine the possible hearing loss related to work site noise, a hearing test was also conducted on 1,374 workers in these work sites. The results of the study were as follows ; 1. Of the total 98 work sites, 57 work sites(58.2%) produced noise exceeding threshold limit value (${\geq}90dBA$) set by the Ministry 01 Labor. In terms of different manufacturing industries the proportion of work sites which exceeded 90dBA was the highest for the cut-stone products industry with 6/6 work sites and lowest for the commercial printing industry with 1/13 work sites. 2. The percentage of workers who were exposed to noise greater than 90dBA was 19.8% (1,040 workers) 01 the total 5,261 workers. In terms of different industries, cut-stone products industry had the most workers exposed to noise exceeding 90dBA with 82.8%, textile bleaching and dyeing industry was next at 30.6% followed by fabricated metal products industry with 27.9%, plastic products manufacturing industry had the lowest percentage of workers exposed to 90dBA exceeding noise with 4.5%. 3. There was a statistically significant correlation between the frequency of noise-induced hearing loss and the percentage of workers exposed to noise exceeding 90dBA (P<0.05). 4. The frequency analysis of noise produced at the 98 work sites revealed that 44 work sites (44.9%) had the maximum sound pressure level at high-frequencies greater than 2KHz. In addition, significantly higher sound pressure level was detected at the high-frequencies at 90dBA exceeding work sites as compared to below 90dBA work sites (P<0.01). 5. The differences in sound level meter's A-and C-weighted sound pressure levels were analysed by frequencies. Of the 28 work sites which showed 0-1 dB difference in the two weighted sound levels, 20 work sites (71.4%) had significantly higher sound pressure levels at high-frequencies greater than 2KHz (P<0.01). Furthermore, there was a tendency for higher sound pressure levels to occur in the high-frequency range as the differences in the two weighted sound levels decreased.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.736-743
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• 2022

Construction workers experience a high rate of fatal incidents from mobile equipment in the industry. One of the major causes is the decline in the acoustic condition of workers due to the constant exposure to construction noise. Previous studies have proposed various ways in which audio sensing and machine learning techniques can be used to track equipment's movement on the construction site but not on the audibility of safety signals. This study develops a novel framework to help automate safety surveillance in the construction site. This is done by detecting the audio sound at a different signal-to-noise ratio of -10db, -5db, 0db, 5db, and 10db to notify the worker of imminent dangers of mobile equipment. The scope of this study is focused on developing a signal processing model to help improve the audible sense of mobile equipment for workers. This study includes three-phase: (a) collect audio data of construction equipment, (b) develop a novel audio-based machine learning model for automated detection of collision hazards to be integrated into intelligent hearing protection devices, and (c) conduct field experiments to investigate the system' efficiency and latency. The outcomes showed that the proposed model detects equipment correctly and can timely notify the workers of hazardous situations.

• Industrial Engineering and Management Systems
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• v.14 no.2
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• pp.175-182
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• 2015

The recent manufacturing industry in Japan has found it difficult to transfer skills from trained workers to inexperienced workers because the former ages and then retires. This is a particular problem for lathe process, as this operation requires explicit and tacit knowledge, and defining the skills clearly in a manual is difficult. This study aims to develop a training system for lathe operation by using a simulator; this includes formulas that help define the relationship between the speed of tool feed and cutting sound/shape of chips which were proposed in the preceding study. The developed training system is verified the effectiveness.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.131-138
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• 2008

The Film-making industry in Korea has significantly expanded during last decade. However, the development didn't necessarily mean there's improvement in terms of the quality of life for the film staffs. In post-production stages, especially, any workers involved in the production can get tremendous amount of mental pressure and stress due to the deadline. Thus, in this period, most labor issues are found and often ignored. In this research, compared to Hollywood, Korean domestic film industry will be analyzed with focus on labor organizations. Their role will be explored and examined in terms of improving the qualify of life as well as of the film itself.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.66-71
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• 1998

This study was investigated to evaluate worker exposures to organic solvents by type of print industry. Results were as follows; 1. Workers were exposed to mixture of toluene, isopropyl alcohol(IPA), methyl ethyl ketone(MEK), n-hexane, ethylacetate(EA), acetone. The components of high exposure solvents were toluene, IPA and MEK. 2. Considering additive effects of the compounds, exposure indices(Em) were calculated. The Mean of exposure indices were 1.79 for Gravere, 0.41 for Screen and 0.14 for Opset workplace. The workers of Gravere workplace were estimated to overexpose for solvents. 3. The highest overexposed solvent was toluene for a single component. The rate of overexposed level for toluene was 7.41% for some print workplace and for mixed solvent was 1.85％. 4. Local exhaust systems were inappropriate and respiratory protective devices were not supplied to the workers. 5. Sound level was over 90dB(A) in Opset print workplace and some measures should be performed to get down the sound level.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.742-752
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• 2010

In case of the working machine that using in the loud-noisy workplace, as it generates the loud-noise, it is influencing a physical, mental bad effect to those workers. Accordingly, though the noise countermeasure for the loud-noisy workplace is acutely requiring, until now, those methods that wearing the soundproof-protection tool, or restriction the working hours, and minimize the noise exposure volume, were mainly used. However, such noise countermeasures occur many problem points. On such point of view, using the acoustic simulation technique, let the workers to choose the workplace where suffering many damages due to the noise of working machine, and after grasp the physical property of working machine and indoor acoustic characteristic, this Study has attempted to grasp the reduction degree of noise level at before-improvement?after-improvement, through the sound-absorption measure. Passing through such preceding step, using auralizational technique based on the noise of working machine of before-improvement after-improvement, and by conduct psycho-acoustics evaluation, this study intended to investigate the change degree of subject reaction. As the result of evaluation, it is considering that the noise-reduction countermeasure method for the loud-noisy workplace could be much effective, through the sound-absorption measure.

• Safety and Health at Work
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• v.8 no.2
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• pp.226-230
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• 2017

The performance of sound barriers was evaluated to determine their technical effectiveness and practicality in reducing noise exposures to operating engineers in construction. Commercially purchased sound dampening mats (SDMats) were installed inside three heavy-equipment engine compartments. Sound pressure levels (SPLs) were measured before and after installing the SDMats while the equipment was on idle and full-throttle settings where it normally operates. SPLs inside the heavy-equipment operator cabs were significantly reduced by 5.6-7.6 dBA on the full-throttle setting following installation of the SDMats (p < 0.01). The evaluated engineering control intervention was simple to install, affordable, and substantially reduced the engine noise reaching the heavy-equipment operator, potentially reducing reliance on hearing-protection devices to protect construction workers from noise exposures.

• Architectural research
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• v.8 no.2
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• pp.11-16
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• 2006

The purpose of this study is to scrutinize the effect of office layouts and ambient office sounds on the performance of office workers involved with a proof-reading test (simple task). Twenty subjects, who were professional researchers and computer programmers, were from three different office layouts: 1) Nine subjects from a combined office type with open meeting places and closed individual offices; 2) five from an open office with rectangular individual workstations, and 3) six from an open office with triangular individual workstations. Architects and consultants working in the field of office have reported from interviews and their own observations that occupants' satisfaction differs as their office layouts vary although the sizes are the same. This finding leads to the hypothesis of this experiment. Proof-reading test results were obtained from three different office layouts (combined office type, rectangular and triangular individual workstations in open offices) under two different sound conditions (quiet background sound and ambient sound of their own workplace) for 10 minutes. The test analysis shows the mean test score of subjects from the triangular individual workstations in open offices is significantly different from the mean test scores of subjects from the combined office type and the rectangular individual workstations in open offices.

• Journal of Audiology & Otology
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• v.25 no.4
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• pp.189-198
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• 2021

Background and Objectives: This study aimed to investigate the occupational performance of Korean workers with and without hearing loss and analyze the hearing-related difficulties in the working environment. Subjects and Methods: The Amsterdam checklist for hearing and work was used for the analyses and the occupational environments of the Korean workers were investigated. Out of 129 total participants, 86 workers experienced severe to profound hearing loss and 43 had the normal hearing ability. The hearing-impaired workers were recruited from two leading vocational centers and normal-hearing workers were their colleagues. Results: The hearing-impaired workers were found to take fewer sick leaves and exhibited higher rates of permanent job statuses compared to the normal-hearing workers. Workers with hearing loss rarely detected background sound; however, they could perceive reverberation more frequently. They felt more satisfied with their careers than the normal hearing workers as they received social support and needed to put their effort into hearing for most hearing activities. Furthermore, the effort in hearing increased with the increase in job demand, job control, social support, and career satisfaction. The working hours per week increased with the increase in age, education level, job demand, job control, and social support. Different trends were observed in 9 out of 12 variables while comparing the data from the present study with that obtained from the hearing-impaired workers of the Netherlands, indicating a large difference between countries. Conclusions: Although the hearing-impaired Korean workers operate diligently with good job positions, it is necessary to enhance their acoustic environment and provide them social support. Considering the cultural background of the hearing-impaired workers, the development of suitable vocational rehabilitation programs and specific questionnaires is strongly recommended worldwide.

• Korean Journal of Audiology
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• v.25 no.4
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• pp.189-199
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• 2021

Background and Objectives: This study aimed to investigate the occupational performance of Korean workers with and without hearing loss and analyze the hearing-related difficulties in the working environment. Subjects and Methods: The Amsterdam checklist for hearing and work was used for the analyses and the occupational environments of the Korean workers were investigated. Out of 129 total participants, 86 workers experienced severe to profound hearing loss and 43 had the normal hearing ability. The hearing-impaired workers were recruited from two leading vocational centers and normal-hearing workers were their colleagues. Results: The hearing-impaired workers were found to take fewer sick leaves and exhibited higher rates of permanent job statuses compared to the normal-hearing workers. Workers with hearing loss rarely detected background sound; however, they could perceive reverberation more frequently. They felt more satisfied with their careers than the normal hearing workers as they received social support and needed to put their effort into hearing for most hearing activities. Furthermore, the effort in hearing increased with the increase in job demand, job control, social support, and career satisfaction. The working hours per week increased with the increase in age, education level, job demand, job control, and social support. Different trends were observed in 9 out of 12 variables while comparing the data from the present study with that obtained from the hearing-impaired workers of the Netherlands, indicating a large difference between countries. Conclusions: Although the hearing-impaired Korean workers operate diligently with good job positions, it is necessary to enhance their acoustic environment and provide them social support. Considering the cultural background of the hearing-impaired workers, the development of suitable vocational rehabilitation programs and specific questionnaires is strongly recommended worldwide.