Noise Pollution: Definition, Harmful Effects, Prevention and Its Control

How often have you been irritated by the loud noise of mics and speakers while you are trying to study or focus on something? In fact, sometimes when we play the television too loudly, or scream a lot while playing with friends in the house, or in the streets, we get scolded by the elders for being too noisy. But what is noise? Noise refers to a loud unpleasant sound caused due to irregular vibrations. 

Did you know that noise above a certain level can not only disturb our peace of mind but can also cause serious health hazards. Which is why noise beyond 85 decibels is considered to be noise pollution. Come, let us learn more about this form of pollution.

Table of contents

• What is noise pollution?
• Sources of noise pollution
• Harmful effects of noise
• Prevention of noise
• Practice problems
• FAQs

What is Noise Pollution?

Noise is the undesired high level of sound. Noise is an air pollutant, it leads to psychological and physiological disorders. The Air (Prevention and Control of Pollution) Act was amended in 1987 by the government of India to include noise pollution in air pollution. Noise is measured in decibels (dB). Noise beyond 85 dB is considered as noise pollution.

Sources of Noise Pollution

The different sources of noise pollution can be crowded and busy places like markets, railway stations, etc, loudspeakers, sound of heavy machinery, honking of vehicles, flying of aeroplanes, construction sites, etc.

Harmful Effects of Noise

Extremely high sound levels (150 dB) or more which can be generated by a jet plane or a rocket taking off, can damage the eardrums resulting in permanent impairment of the hearing ability. Also, chronic exposure to a comparatively lower noise level of the cities can permanently damage the hearing abilities of humans. Noise also causes insomnia, increased heart beat, changes in breathing pattern, considerably stressing humans. 

Prevention of Noise

Reduction of noise in our industries can be affected by use of sound absorbent materials or by muffling (reducing) noise by planting trees. Strict following of laws put forth, in relation to noise like having horn-free zones around hospitals and schools, permissible sound-levels of crackers and of loudspeakers, timings after which loudspeakers cannot be played, etc., have to be enforced to protect ourselves from noise pollution. 

Practice Problems of Noise Pollution

Question1. When was The Air (Prevention and Control of Pollution) Act first implemented, and when it was later amended, to include noise as a pollutant. ?

A. 1981, 1987
B. 1882, 1986
C. 1986, 1987
D. 1987, 1981

Answer: The Air (Prevention and Control of Pollution) Act was first implemented in 1981 and later amended in 1987 to include noise as a pollutant. It is an Act of the Parliament of India to control and prevent air pollution in India and for the establishment of Pollution Control Boards.

Thus, the correct option is (a).

Question2. Select the correct statement, among the following regarding noise pollution?

1. Loud music concerts are generally not considered as a source of noise pollution.
2. Noise is considered an invisible danger.
3. Noise can be used as therapy for certain psychological disorders.
4. Sound only above a certain decibel level is considered as noise.

A. Statements i and ii
B. Statements i, ii and iv
C. Statements ii and iv
D. All four statements

Answer: Loud music concerts are considered as noise polluters, however they are permitted to be organised provided that they adhere to noise regulatory rules of the place. Thus statement i is false. Noise is considered to be an invisible danger as sound waves are not visible and noise poses serious health hazards, both psychological and physiological disorders in humans and animals. Hence statement ii is true. Sound therapy includes a range of therapies where sound is used to treat physical and mental conditions. Eg: Music therapy - It involves a person listening to music to relieve stress and muscle tension. However, noise is loud and undesirable and it cannot be used for therapy rather it is a cause for health hazards. Hence statement (iii) is incorrect. Sound is measured in units called decibel (dB). Normal conversation is about 60 dB and generally sound intensity above 85 dB is considered as noise pollution. Thus, statement iv is correct.

Question3. Match the following in regards to the source of noise pollution given in column I with a suitable control measure listed in column II and select the correct option.

A. I - R, II - Q, III - P
B. I - P, II - R, III - Q
C. I - Q, II - R, III - P
D. I - R, II - P, III - Q

Answer: Reduction of noise in our industries can be affected by use of sound absorbent materials or by muffling (reducing) noise. The surroundings of hospitals are declared as “silence zones” so that patients receiving treatment are not disturbed due to any noise. Also the areas around schools, colleges, courts and other such places that need to be noise-free. Vehicles are required, by law, to be fitted with silencers to reduce the engine noise and have to adhere to the ‘no honking’ rule in These “silence zones”. The regulations for permissible sound-levels of crackers and of loudspeakers, timings after which loudspeakers cannot be played etc. have to be implemented to control noise pollution from the aforementioned sources. Thus, the correct option is (a).

Question4. What are the different methods of controlling noise pollution?

Answer: Noise pollution can be controlled by -

• Reducing the use of loudspeakers.
• Planting trees around heavy noise producing centres such as airports, industries, etc to absorb the noise.
• Using sound absorbing materials to build walls of auditoriums and theatres.
• Avoiding unnecessary honking of vehicles.
• Setting permissible limits for the use of sound producing crackers, timings for playing loud speakers, etc.

FAQs of Noise Pollution

Question1. What will happen if a human being is exposed to noise above 120dB?

Answer: Sound is measured in decibels (dB). Noise is an unpleasant sound composed of irregular sound waves and noise above 85dB is considered to be noise pollution as it is harmful for the human body. A noise above 120dB can immediately cause debilitating effects on the human ear such as rupturing of the ear drum which can lead to permanent deafness.

Question2. Why are airports set up far away from residential settlements?

Answer: The sound of aeroplanes taking off can be as high as 120dB or above which can cause permanent damage to the human ear. Thus, airports are set up far away from human settlements and are usually surrounded by trees to absorb the noise.

Question3. Can noise pollution affect other functions of the human body, apart from hearing? 

Answer: Noise pollution can not only cause hearing disability but it can also cause improper sleep issues, stress, altered breathing pattern, and increase in heart beat.

Question4. Does noise pollution affect our work efficiency?

Answer: Noise pollution can affect our peace of mind and concentration and make us irritable and distracted. Thus it can affect our work efficiency.