Noise may not seem as harmful as the pollution of air or water but it is also a severe problem that affects human health and can contribute to a general deterioration of environmental daily. NOISE:
The word “Noise” derived from the Latin word “Nausea” meaning seasickness, or any sensation of disgust, annoyance or discomfort. The most common definition of noise is “Unwanted Sound”. A sound might be unwanted because it is; •
Unpleasant or annoying
Intrusive or distracting
Noise is defined as “unwanted sound”. Sound, which pleases the listeners, is music and that which causes pain and annoyance is noise. OR
“Noise pollution refers to sounds in the environment that are caused by humans and that threaten the health or welfare of human or animal inhabitants”. Noise pollution is the type of environmental voices that disrupts the activity or balance of human or animal life. The word noise may be from the Latin word nauseas, which means disgust or discomfort. The source of most outdoor noise worldwide is mainly construction and transportation systems, including motor vehicle noise, aircraft noise, and rail noise. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area. High noise levels can contribute to cardiovascular effects in humans, a rise in blood pressure, and an increase in stress and vasoconstriction, and an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by affecting their ability of prey detection, interfere with reproduction and navigation, and contribute to permanent hearing loss.
Loudness/noise intensity is measured in decibels (db)
Loudness of a sound is dependent upon proximity to source of sound •
No damage will be done to the ear if the sound level is below 80 db •
Steady exposure to sounds higher than 80 db can have negative long term effects on hearing. •
The lowest sound pressure that can be heard, 20 db is whisper, 40 db the noise in a quiet office. 60 db is normal conversation, 80 db is the level at which sound becomes physically painful.
NOISE LEVEL OF COMMON SOUND:
The decibel scale (db) is logarithmic each 10 db result in doubling of loudness intensity. Threshold of hearing
Motorcycle (30 feet
Food blender (3 feet)
Quiet whisper (3 feet)
Diesel truck (30 feet)
Personal music system
Car stereo system
Loud singing (3 feet)
Amplified Rock and Roll
Automobile (25 feet)
Jet plane (100 feet)
NOISE STUDIES CONDUCTED IN DIFFERENT CITIES OF PAKISTAN:
Random tests in different cities showed that the noise level in most of the areas was as high as 70-90 db (A) which is much higher than the acceptable limit.
SOURCES OF NOISE POLLUTION:
The sources of noise are more in urban and industrial areas than in rural areas. The source of noise pollution may be stationary or mobile.
Use of loudspeaker on various occasions like festivals, elections, worships in temples, mosques and during advertisement, use of bulldozers, drivels, household equipment like vacuum cleaner, TV, radio, kitchen appliances like grinder, mixer etc common vegetable and fish markets. They do not cause too much problem but their effect cannot be neglected.
Noise can also be caused by...
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