Definition
Noise:
Audible sound from traffic, construction, and so on that may generate unpleasant and harmful effects (hearing loss). It is measured in decibels.
Universe
Sampling frame consists of master sample chosen from census 1997, and this master sample comprises geographical areas closed in size (number of households) which is the enumeration areas used in census, such frame has been used as the Primary Sampling Units (PSUs) in the first stage of selection