Introduction
Former U.S. Surgeon General William H. Stewart said in 1978, “Calling noise a nuisance is like calling smog an inconve- nience. Noise must be considered a haz- ard to the health of people everywhere.”
A number of studies have shown that high noise levels can contribute to sig- nificant cardiovascular effects and even exposure to moderately high noise levels during a single eight-hour period can a statistical rise in blood pressure of five to ten points and an increase in stress[1-4); Vasoconstriction or narrowing of the arteries, and increased incidence of coronary artery disease. In addition, chronic exposure to noise may cause noise-induced hearing loss.
The degree of annoyance from noise produced by multiple sources is not fully understood but has been identified as a problem in environments operating equipment with varied noise levels and frequencies. There is evidence that com- bined sources of noise pollution lead to an increased level of stress and aggrava- tion which can have a negative impact on efficiency, health and quality of work.