Noise is any excessive, unpleasant sound that causes disturbance. The word noise comes from the Latin word Nausea. The intensity of sound is measured in decibels. WHO states sound level up to 70decibel as not harmful but, anything beyond 85dB as hazardous. Noise or Sound pollution has negative impacts on health as well as the quality of life of all organisms. The prevalence of noise is increasing in magnitude and severity as urban lifestyle changes.

1.Main Types of Pollution

 1.1Manmade: The main sources are road traffic, railways, industrial operations, construction work, and aircraft. In addition to this, the use of electrical appliances and various types of gatherings also results in increased noise levels.

 1.2. Environmental: Sound of volcanic eruptions and thunderstorms that go up to 140 dB are natural environment sounds that cause sound pollution.

2.Causes of pollution

2.1. Industrial causes: Factories with heavy machinery emit a high amount of sounds. Industrial towns close to residential areas always cause discomfort and health problems. Likewise, burglar alarms, air conditioning systems, and ventilating systems installed in factories also contribute to the cause.

2.2. Construction site activities: Activities like mining, excavation, piling, road work cause sound pollution. Moreover, demolition and renovation activities can also severely impact the hearing of workers.

2.3. Social Events: Loud sound systems used during festivals and political gatherings also often create disturbing noise. Public places liken open markets and parks are also sources of pollution. Though these may seem harmless, it has far-reaching consequences in the long run.

2.4.Transportation: Honking of buses, trucks, cars contribute to disturbances. Correspondingly, underground trains, and airplanes similarly produce intense noises. Supersonic jets creates high energy sounds like a close thunderclap also called sonic boom. Such high noise levels are extremely hazardous

2.5. Household appliances: Extensive use of gadgets in households also contribute to sound pollution. Electrical appliances like grinders, vacuum cleaners, air conditioners release unpleasant sound along with musical instruments and intruder alarms.

 3. Effects and Health Hazards

3.1. Hearing Problems: Constant exposure to high intensity sounds damage eardrums resulting in loss of hearing or deafness. Level of noise, distance from the source, and time exposure play a major role in hearing loss.

3.2.Physical Problems: Extreme noise causes headaches, high blood pressure, racing pulse, and even heart attack.

3.3.Psychological effects: Noise pollution can be linked to sleep disorders, constant stress, fatigue, depression, and anxiety. Along with this, there can be aggressive behavior,  hysteria, and hypertension. It may also cause emotional disturbances and mental imbalance. It can even cause communication problems. All these subsequently lead to chronic health problems.

3.4.Behavioral changes in animals: Animals have a better sense of hearing than humans for survival. Some require sound waves to locate prey and for migration. Consequently, they may become inefficient in hunting and loss of hearing, coupled with a reduced response. As a matter of fact, this affects even their reproduction, leading to disturbance in the balance of the ecosystem.

 

4.Control Measures:

4.1.Source Control:  This is the most direct and effective approach to control noise pollution. Proper lubrication and better maintenance of machines, installing silencers, Insulation of factories, and sound-producing equipment with sound-absorbing materials will help in general. Manufacture and sale of crackers that produce high-intensity sound should be prohibited.

4.2.Noise attenuation: The dissipation of noise helps to reduce the impact of loud noise. Grow trees around factory premises, highway sides, and aerodromes to attenuate noise.

4.3. Protecting the receivers: This is a defensive measure from impending noise menace. Those constantly exposed to noise can use ear covers earplugs etc. might help.

4.4. Absorptive panels and acoustical barriers: Absorptive panels are effective in reducing sound pollution between residential neighborhoods and busy freeways. Acoustical barriers block the direct travel of sound waves over the top or around the barrier. These are uniquely and successfully implemented in some cities and has proven to improve public conditions in general.

4.6. Legal Measures: Above all, establishing legislative regulations that include preventive and corrective measures is an effective control measure. Many nations have enacted laws to penalize the generation of excessive noise. Moreover, imposing penalties and raising proper awareness are also effective measures. In some countries, phonometers (a device used to measure the intensity of sound) are installed along the highways. And, penalties are imposed on vehicles that emit sound beyond limits. Furthermore, in India, under Section 13 of Criminal Procedure Code, district magistrates are empowered to make conditional order calling upon persons indulged in such activities.

4.1.1 Additional facts:

• Chennai is the most noisest among the six metro cities(Central Pollution Control Board data), Guindy being the noisiest place.
• Mumbai traffic police launched a campaign called Punishing signal. Throughout the city, special decibel meters are connected to traffic signals.
• Karnataka Pollution Control Board has decided to conduct a noise pollution mapping survey so as to identify hotspots, where the noise level exceeds the safe limit.
• In Kerala, district authorities have banned the use of loudspeakers/sound systems in thickly populated city premises. The state has taken steps to impose penalties so that it will help to curb noise pollution.

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