EXAMINATION OF NOISE POLLUTION

CHAPTER ONE
INTRODUCTION 
1.1 BACKGROUND OF THE STUDY
Noise is not often thought as a pollutant, but unwanted sound (noise) can seriously degrade the quantity of life, the acceptance of noise by people obviously depends on the individual, but it has been legislated on levels of sound acceptable to the community. (Agbalagba, 2017). The level of noise deemed to be acceptable is dependent upon The type of environment: acceptable levels of surroundings noise are affected by the type of activity, A library, for, has different requirements to those on a factory floor Frequency structure: different noises contain different frequencies and some frequencies are found to be more annoying than lower frequency rumbles. Duration: a short period of high level noise is less likely to annoy than a long period. Different people have different hearing sensitivities, but average values can be measured and provide a map of the sound that the human ear can detect, the threshold of hearing is the weakest sound that the average human hearing can detect, the threshold varies slightly with the individual, but it is remarkably low, there is also high threshold, the threshold of pain, which is the strongest sound that the human ear can tolerate.
Absolute measurements of sound intensity can be expressed in either Wm-2 or in sound pressure pa, but such units do not correspond directly to the way in which the human ear responds to sound levels, since the human ear has a non-linear response to the energy content of sound, a logarithm scale is used to describe the response of the ear, it is converted to sound level measured in decibels. (Agbalagba, 2017).