Any abnormal change in anything is called pollution . Any kind of pollution is dangerous for mankind . Sound is a symptom of life . The very existence of life is felt and perceived through the presence of sound . But loud and shrill sound creates a cacophony instead of a symphony . Of late , sound pollution has reached an alarming stage in human life . In schools , colleges , offices, market places , cities and towns even in hospitals , we have an explosion of defending sound . We have noise from motor vehicles , mills and factories airplanes, domestic appliances, like radios , cassette players , televisions and so on . The quietness of our life has totally vanished . The extent of sound pollution has already crossed the normal limits of human endurance. Specialists say, that it is disastrous for us . According to UN, the normal hearing limit of sound is 45 decibels . Serious harm can be caused to people , if the regularly exposed to sound exceeding 70 decibels . It affects our hearing , our nerves, our ability to work efficiently and our general health . Sound pollution is unbearable for the ill people . We have to pass strict laws to take effective steps against the misuse of microphones . People must be made aware of the dangers of sound pollution . Strict laws must be farmed to control the electric horns within the limits of the city.