title: The Risk Rating System for Noise-induced Hearing Loss in Korean Manufacturing Sites Based on the 2009 Survey on Work Environments.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  This study offered NIHL prevention measures which are fit for the worksites in each risk grade.
authors.affiliation: Occupational Safety and Health Research Institute, Koera Occupational Safety and Health Agency, Incheon, Korea.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Youn Ho
authors.initials: YH
authors.lastname: Cho
authors.forename: Oh Jun
authors.initials: OJ
authors.lastname: Kwon
authors.forename: Seong Weon
authors.initials: SW
authors.lastname: Choi
authors.forename: Kyung Yong
authors.initials: KY
authors.lastname: Rhee