A research on impulse noise reduction based on noise exposure survey

Introduction
Noise is the cause of noise-induced hearing loss, and has been studies for many years as a subject of occupational health research. Although there are prevention measures against problems associated with noise, the issues of impulse noise in industrial and construction sites of Korea are difficult to measure and evaluate due to limited access, inadequate application of related regulation, confidentiality issues and so on. In Korea, exposure limits to impulse noise are not strict, and regulating impulse-noise generating workplaces is difficult. Therefore, identifying workers with hearing impairments caused by impulse noise is not easy

Methods
Based on the data from National Survey on Work Conditions and Construction Machinery Registration Data, this study aims to identify industries and occupations where impulse noise is often detected and use the analysis on impulse noise as a reference when revising related standards.

Results
Since impulse noise can reach the maximum sound pressure level in less than a second and can exceed120dB, the methods for measuring and analyzing impulse noise are very different from that of other noises.

Discussion
An analysis of noise generation in different locations revealed that the main sources of impulse noise are gunshots in military shooting ranges, pile hammers in construction sites, and impact wrenches in industrial sites. After recording the noise sources, the waveforms are analyzed to find out the rising time reaching the maximum sound pressure level, the sustained time of sound pressure, and sound pressure level, which help to understand impulse noise.