Combined Effects of Exposure to Noise and Whole-Body Vibration in Dumpers, Helicopters and Railway Engines

Abstract

Three groups of 24 subjects were exposed to alternated periods of noise, vibration and combined exposures of both stimuli, recorded during working conditions in a dumper, a helicopter and a railway engine, respectively. Each condition included 30 minutes' exposure during which wakefulness and performance were measured by means of EEG and a computerized test respectively. The subjects also rated their drowsiness and annoyance. Results of the EEG measurements indicated the lowest level of wakefulness during the combined exposure in all three environments. The differences in ratings of drowsiness between exposures also tended to be higher during the period of combined exposures. The rated annoyance levels were always at the highest level during the combined exposure. Almost equal performance levels were found during the periods of exposure.