Study Relationship Between Noise Metrics Parameters Exposure Among Electrical Production Workers

Abstract

This paper represent the exposure–response relationships for noise-induced hearing loss are relatively well established, metrics of noise exposure are best represent risk of hearing damage. In particular, while equivalent sound pressure level L_eq, based on a 3dB exchange rate (ER) is used by most agencies, USOSHA’s standard is based on the L_avg, which uses a 5 dB ER. In addition, peak levels of exposure, which are commonly found in some industries, including electrical site are believed to increase risk above that predicted by the L_eq. This paper presents an analysis of noise matrix exposures parameters among electrical  workers, comparing several noise metrics, over time intervals measurements such as 60, 180, 300, 480 minutes. Metrics examined were the L_avg, L_eq, L_min and L_max, expressing average levels of exposure across an exposure interval. Two novel metrics were derived from these monitored metrics, L_eq/L_avg and L_max/L_eq, as measures of exposure variability and ‘peakiness’, respectively. A time intervals of noise matrix exposure to workers in three sites (Metal, Epoxy and Cutting workshop) with different activities were examined. Correlations between average metrics (L_eq, L_avg and L_max) are generally around very high and well, while the variability of ratio metrics are between middle and poorly correlated with either average levels, or with each other, indicating that they characterize different aspects of exposure at 480 minutes interval. The specific activities of each sites estimates of exposure using the various metrics will be applied to the cohort's work history to explore the importance of this matrix in estimating risk of noise- exposure that induced damage