Difference between Sound and Noise. Discuss sources & effects of Noise pollution.
Difference between Sound and Noise
| Parameter |
Sound |
Noise |
| Definition |
It is defined as the continuous vibrations that travel from one medium to another |
It is defined as the unpleasant sound that causes disturbance |
| Effects on health |
Sound has a positive effect on the health |
Noise has a negative effect on health like hearing loss, hypertension |
| Connotation |
Sound carries a positive connotation as it is audible, distinctive, relevant and definitive |
Noise carries a negative connotation as it is irrelevant, incompressible |
Sources of Noise Pollution
Following are the main sources of noise pollution
- Traffic sources
- Industrial sources
- Constructional sources
- Other miscellaneous sources
Traffic sources
Noise created by various means of transport like trucks, tractors, buses, trains, aeroplanes, etc are the traffic related source of noise pollution.
It may be in the form of:
- Horn of vehicles
- Raise of accelerator
- Vehicle with damaged silencer
- Noise produced by a diesel car will be more than that produced by a petrol car.
- A jet aircraft will produce more noise than a propeller type of aircraft.
Industrial sources
Noise is the essential by product of industry, its intensity and nature being dependent upon the type of industry.
Industrial noises are usually produced by:
- Reciprocating or rotating machinery
- Cutting of materials, grinding
- Blow hammers
- Generators
- High pressure and high velocity gases, etc
Constructional sources
Noises produced by various constructional activities are:
- Rock crusher for production of aggregate
- Pile driving equipment
- Boring and drilling equipment
- Road rollers
- Materials handling by conveyers
- Rock blasting
Other miscellaneous sources
- In residential area – loud voice of T.V., music systems, radio, etc
- Public address system – public functions, Navratry festival etc.
- Sirens – Police van, industries, ambulance
- Military sources – noise of bomb, grenade explosion, tanks other vehicles, missiles etc.
- Use of crackers during Diwali and other celebrations.
- Shouting of hawkers at market places
Noise pollution effects
Major effects:
- Loss of hearing
- Annoyance
- Health effects
- Interference with communication
- Working efficiency
Loss of hearing
Loss of hearing occur due to exposure of noise, which is termed as artificial hearing loss. This loss is divided into two types:
- Noise Induced Temporary Threshold Shifts (NITTS):
This is caused due to exposure to loud noise like bursting of crackers. This can be recovered in a short period of time.
- Noise Induced Permanent Threshold Shifts (NIPTS):
This occurs because of exposure to loud noise for a long period of time.
Annoyance
This is a subjective matter for a noise. Someone may like classical music, it may annoy other. General annoyance is felt at about 75 to 85 db. Blood vessels get constricted, breathing rate is affected and musical tension changes.
Health Effects
- Effect on physical health: Auditory effects and Non auditory effects.
Auditory effects: They are grouped into short time and long-time effects. Acoustic trauma is caused by a very high intensity impulsive noise of about 150 db or more from explosion.
Non - auditory effects:Exposure to a loud noise may increase the pulse rate and blood pressure changes. Body experiences fear reactions. Disturbed brain waves lead to the interference in vision.
- Effect on mental health:Effect on mental health is less.
Lack of concentration at high noise level and mental disorientation are some of the effects on mental health.
Interference with communication
A person may face the problem of trying to understand another person talking to him/her in an environment with high background noise level.
Background noise level can thus affect the efficiency of offices, school and other places where communication is of vital importance.
External sounds can also interfere with conversation and use of telephone.
Working efficiency
It is found to be decreased drastically whenever a person is working in the noisy environment.
Experiments indicate that irregular bursts of noise are more disruptive than steady noises.
Other effect
- Sleep interference
- Increased industrial accidents
- Personal comfort interference
- Property value degradation
