4. IT’S SOURCES
The sour ce of most out door noise wor ldwide is:
• Tr anspor t at ion Syst ems: mot or vehicle noise,
• air cr af t noise and r ail noise.
• Poor ur ban planning may give r ise t o noise
pollut ion.
• Ot her sour ces: of indoor and out door noise
pollut ion ar e car alarms, emer gency ser vice
sir ens, of f ice equipment , f act or y machiner y,
const r uct ion wor k, gr ounds keeping equipment ,
bar king dogs, appliances, power t ools, light ing
hum, audio ent er t ainment syst ems, loudspeaker s,
5. MEASUREMENT
A DECIBEL is the standard for the
measurement of noise. The zero on a decibel
scale is at the threshold of hearing. 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.
• The Noise quantum of some of the cities in
our country indicate their pitch in decibel
in the nosiest areas of corresponding cities,
e.g. Delhi- 80 db, Kolkata - 87,Bombay-85,
Chennai-89 db etc.
6. Human Health
Effects Noise health effects are both health and
behavioral in nature. The unwanted sound
is called noise. This unwanted sound can
damage physiological and psychological
health. Noise pollution can cause:
• Annoyance and aggression: behavioural
changes
• Hypertension: health problems
• High stress levels: health problems
• Tinnitus: forgetfulness,serve depression
and panic attacks
7. HUMAN HEALTH
EFFECTS(contd.)
• Chronic exposure: hearing loss
• Sleep disturbances and other harmful
effects.
• Cardiovascular effects
• Statistical rise in blood pressure
• Vasoconstriction leading to the increased
blood pressure
• Increased incidence of coronary artery
disease.
8. Environmental Ef f ects
Noise can have a detrimental effect on
animals:
• By causing stress.
• Increasing risk of death by changing
the delicate balance in predator/prey
detection and avoidance.
• By interfering with their use of sounds
in communication especially in
relation to reproduction and in
navigation.
• Acoustic overexposure can lead to
temporary or permanent loss of
hearing.
• May cause endangered species to
become extinct. One of the best known
cases of damage caused by noise
pollution is the death of certain
species of beached whales, brought on
by the loud sound of military sonar.
9. Mitigation
the sound tube in Melbourne,
australia, is designed to reduce
roadway noise without detracting
froM the area's aesthetics.
10. Noise Control
Technology to mitigate or remove noise can be applied as follows:
• There are a variety of strategies for mitigating roadway noise
including:
• Use of noise barriers, limitation of vehicle speeds
• Alteration of roadway surface texture
• Limitation of heavy vehicles
• Use of traffic controls that smooth vehicle flow to reduce braking and
acceleration
• Tire design.
• Costs of building-in mitigation can be modest, provided these solutions
are sought in the planning stage of a roadway project.
12. LASTWORDS
There is need to creating general awareness towards
the hazardous effects of noise pollution. Particularly,
in our country the people generally lack consciousness
of the ill effects which noise pollution creates ad how
the society including they themselves stand to
beneficiary preventing generation and emission of
noise pollution. The target area should be educational
institutions and more particularly school. The young
children of impressionable age should be motivated to
desist from playing with firecrackers, use of high
sound producing equipments and instruments on