2.2 Effects of Noise on Human Health
Exposure to high levels of noise over a long time causes harmful physiological effects.
The detrimental effects of noise depend not only on its SPL and frequency, but also
on the total duration of exposure and the age, general health and susceptibility of the
individual. Harmful effects of noise can be broadly classified into, auditory effects, nonauditory
effects and threshold shift [12,13]. Fig. 2.1 represents the noise exposure effects
on human health.
Figure 2.1: Noise exposure effects on human health [13]
2.3 Basics of Sound
Sound arises when fluctuations in air pressure give rise to pressure waves which travel
through the atmosphere. As they travel they will interact in various ways with their
surroundings. Noise is a word which is normally applied to unwanted sound and the
sound present in most work situations is unwanted, so it was normally talked about
exposure to workplace noise rather than to workplace sound [14, 15]. It also defined that
smallest audible smallest audible at the frequency of greatest sensitivity in young people
with clinically normal ears