ABSTRACT
It is important to have some understanding of the nature of sound, because every noise is a type of sound.
Noise is usually defined as unwanted sound. Thus it can present with variations in magnitude that may
be temporal or spatial in nature or a combination of both. A particular type of noise is known as
environmental noise which is noise that is generated by a variety of outdoor sources and then propagates
from outdoors to receivers that may be situated either indoors or outdoors. In turn, road traffic noise is
one type of environmental noise.
