Several surveys conducted in many large cities of the world have indicated that noise is the most loathsome form of environmental pollution. The disgusting noise originated from road traffic, vacuum cleaners and heavy industrial machinery has been identified as a fundamental cause of hearing impairment in many individuals. Noise pollution is a significant environmental problem; however, it is worth noting that every sound is not noise.
Sound and Noise
Sound is generated by producing vibrations in the air; when these vibrations reach ears, they stimulate hearing. The intensity or loudness of sound is measured relative to a reference sound so low that it is almost inaudible to human ear. The relative loudness of sound is expressed in the units of decibel (db). Sound takes the form of noise when it gets disagreeably loud and results in physiological and psychological harm.
Sources of Noise Pollution
Most of the noise present in the environment is human-induced: road vehicles, trains, power boats, snowmobiles, lawn mowers and overhead flying jets are prominent sources of excessive noise. Cars with stereo booming and heavy traffic on roads are other examples. Indoors sources like dishwashers, trash compactors, washing machines, televisions and stereos add to the din. Industrial chain saws, jackhammers and heavy duty electric generators contribute to industrial noise pollution.
Effects of Noise Pollution
Prolonged exposure to high-intensity noise can cause permanent hearing impairment; loud high-pitched noise can damage the cochlea, the part of the inner ear that perceives sound. Further to loss of hearing, noise may cause other bodily changes such as increased heartbeats, dilation of pupils and muscle contraction. Prolonged exposure to noise may cause a permanent constriction in blood vessels, thereby contributing to heart disease. Other harmful implications include migraine headaches, nausea, gastric ulcers and depression.
Controlling Noise Pollution
The most obvious remedy to noise pollution is to produce less noise; restricting the use of sirens and horns at busy streets, for example. In addition, re-engineering of cars, motorbikes, vacuum cleaners and other noisy devices for lesser noise can also be effective. Putting dampening shields between the source and the hearer can also help. Examples of this approach include noise barriers erected along highways and noise absorbing materials installed around dishwashers.
Restricting the noise at the receiver end can also be worthwhile regarding noise control; use of earplugs near heavy machinery such as electric generators, jackhammers and chainsaws can be helpful in protecting against hearing loss.
Noise Pollution and Its Impacts
Noise generated by road traffic, home appliances and industrial machinery is a major cause of hearing impairments and other disorders in humans. Reduction of noise sources by improved designs of machines and appliances can help reduce noise pollution. Installation of noise dampeners between sources and receivers is also significant. In addition, ear protectors should be worn near sources of noise to lessen the harmful effects on hearing ability.
Source:
2001, Raven & Berg, Environment, Harcourt Inc.
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Zeeshan Amin - I am a professional mechanical engineer with a diverse experience of over 5 years with Honda Cars, Shell Oil and Nestle.
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