IRCT2015110424875N1 IRCT 2016-01-12 Research manager of Iran University of Medical Science Effect of traffic noise on saliva cortisol and alpha amylase during driving Evaluation of the traffic noise effect on saliva cortisol and alpha amylase during driving activity 2016-04-20 anticipated 56 Complete https://irct.ir/trial/20917 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Single, Purpose: Prevention. 3 The effect of traffic noise on secretion of cortisol and alpha amylase. In order to determining the effects of noise on stress hormones, people will expose to recorded traffic noise during driving activity. The levels of stress hormones such as cortisol and alpha amylase, as stress index before and after doing experiments will be measured..