The effect of below exposure noise threshold limit value to acute stress

Introduction This study aims to examine the possibility of the effect of noise with intensity below the threshold value to stress. Method The study is a quasi-experimental involved 108 subjects divided into 6 noise exposure groups of control, 0 dBA, 70 dBA, 75 dBA, 80 dBA and 85 dBA in 15 min exposure. Research subjects consisted of healthy males, aged 18 - 39 years and met the study criteria. Assessment of stress include physical stress index (PSI), the total power (TP) and low frequency/high frequency ratio (the ratio of LF/HF) measured using the test heart rate variability (HRV), adrenaline and cortisol blood levels measured before and after treatment. Result Research subjects who qualify as many as 102 people a year aged 23.99±4.77 years. Research subjects have equal characteristics between treatment groups according to the socio-demography. There is no different of PSI value, the ratio of TP and LF/HF, Adrenaline between exposure groups. Cortisol levels were positively correlated with higher levels of adrenaline (r=0.35, p<0.01) while adrenaline levels and cortisol levels were strongly positively correlated (r=0.53, p<0.01). PSI values weakly positively correlated with cortisol levels (r=0.2, p<0.05) and the ratio LF/HF were positively correlated weakly with cortisol (r=0.2, p<0.05). Discussion Effect of noise on the stress intensity visible starting at Laeq, 65 dBA and Laeq 8 hour, 8 hour 70 dBA. Correlation parameter values autonomic balance system with adrenaline and cortisol levels demonstrate the potential use of HRV as a psychophysiological assessment instruments due to noise disturbance.