1-Measuring Sound Intensity:

        Sound intensity in measured by a universal unit called a decibel. The normal human ear responds to sound within a range of 130 decibels. It is also affected according to its intensity and time of exposure. Hearing is affected if the human ear is subjected to a sound waves greater than 80 decibels for several hours everyday. As a result, nervous tension and complete deafness may occur which is what happens to laborers in factories. 

        If a person is subjected to the sudden uproar of a jet plane or a great explosion, he is liable to have a nervous disorder associated with high blood pressure.

        Animals are also affected by sound pollution. Experimental rats died when they were subjected to a sound intensity of 175 decibels for several hours. Others became ill when they were subjected to sound waves of 100 decibels due to the percentage of ammonia increasing in the blood. Other developed heart congestion, vasoconstriction and nervous tension.