Fatigue effects of noise on aeroplane mechanics

Subjective fatigue and reaction time performance were measured in a group of 24 aeroplane mechanics, during 1 week of high noise exposure and 1 week of low noise exposure. Subjective ratings were collected before and after each work day. On the last day of each week subjects also completed a reaction time task before and after work. The mechanics felt more sleepy and less energetic during the high noise week. This effect was most evident towards the end of the day and there was a build-up of the effect during the week. Reaction times were prolonged during the high noise week. Possible confounding factors are discussed and found to be less likely explanations of the effects.