Transcript NOISE AND HEARING LOSS

Noise: The Invisible Hazard
WHAT IS NOISE?
WHAT ARE THE EFFECTS OF
NOISE?
WHY MORE STRESS ON
NOISE?
Did you know...
...noise is the most common hazard?
...hearing loss from noise is slow and
painless;
you can have a disability before you notice
it?
...hazardous noise is found off the job
from things like power tools, lawn mowers
and guns?
...you can protect yourself from hazardous
noise?
Noise is often defined as
undesired or unwanted sound or
sound without agreeable musical
quality.
BUT,
this definition is subjective
because of the fact that one
man’s sound is other man’s
noise, so we can define noise
in a better way as :
Noise is “wrong sound in
wrong place at wrong time.”
Sources of noise:
They are many and varied:
Automobiles
Factories
Industries
Aircrafts
Domestic like TV , coolers ,
mixies etc .all adding to the
quantum of noise in daily life.
Effect of noise on ears:
They are of two types:-Non-auditory.
Auditory
NON-AUDITORY EFFECTS:
Interference with speech
Communication:
Annoyance:
EFFICIENCY:
FATIGUE:
PHYSIOLOGICAL EFFECTS
PHYSIOLOGICAL EFFECTS
Rise in B.P,
Rise in intra cranial pressure,
Increase in heart rate,
Breathing,
Sweating,
General symptoms like giddiness,
Nausea may also occur.
Noise interferes with sleep.
AUDITORY EFFECTS:
It appears in the 90db.region and is
greatest at 4000Hz,may be
associated with whistling and
buzzing in the ears.
The most serious pathological
auditory effect is DEAFNESS or
hearing loss.
This loss can be:
Temporary
Permanent
Repeated or continous exposure
to noise around 100 db may result
in permanent hearing loss.
Exposure to noise above 160db
may rupture tympanic membrane
that leads to permanent loss of
hearing.
Every person responds
differently to noise.
ROUTINE NOISE LEVELS IN
DECIBLES:
Whispering 20-30db.
Slow and soft music 40-50db.
Normal conversation 60-65db.
Heavy traffic
80db.
Air -plane
120db.
Jet engine
140db.
COMMERCIAL NOISE
LEVELS IN DECIBLES
Type writer
80db.
Lathe machine
85db.
Fabrication workshop 100db.
Drill machine
110db.
Blasting
110db.
ACCEPTABLE NOISE LEVELS
Residential:
Bedroom 25db.
Living room 40db
Office
35-45db.
Conferences 40-45db.
Workshop
40-60db.
Laboratory
40-50db.
Class room 30-40db.
Library
35-45db.
Hospital wards
20-35db.
A daily exposure up to 85db is
above the limit people can
tolerate without substantial
damage to their hearing.
SAFE ZONE
UP TO 85db
DANGER ZONE
90-120db.
DANGEROUS ZONE >120db.
Common sounds may be
louder than you think...
Factors affecting injury to ear
due to noise exposure:
Intensity
Frequency range
Duration of exposure
Individual susceptibility
NOISE CONTROL
Control of noise at source
Control of transmission:- this
maybe achieved by:
Building enclosures.
Covering the room wall and floor
with sound absorbing material.
Protection of exposed
persons:Employees must be regularly
rotated from noisy areas.
-Periodic audiogram checks .
-Use of ear plugs /muffs are
also essential
No noise abatement
programme can succeed
without people’s
participation.
The main aim of this information
is to motivate people against
noise pollution in their daily
living activities and lead an
improved quality of life.
THANKS