Road traffic noise, noise sensitivity and psychological disorder.

The relationship between traffic noise exposure and psychological morbidity was assessed using the population-based Caerphilly Collaborative Survey of 2398 men from Caerphilly, South Wales, UK. The findings showed that annoyance to noise was strongly associated with traffic noise exposure levels. Men with noise sensitivity were more likely to be highly annoyed by noise exposure than men with less noise sensitivity. There was no direct association between noise exposure level and psychological morbidity until the results were stratified by noise sensitivity. This revealed a gradient of increasing psychological morbidity with increasing noise level in the lower two tertiles of noise sensitivity. No gradient was found in the highest tertile of noise sensitivity. The role of noise sensitivity is argued to be either an indicator of vulnerability to environmental stressors or a measure of overreporting.