Download Noise_(Larry)

HEARING
CONSERVATION
Hearing Loss

Can you imagine not being
able to:
– Hear music?
– Listen to the sounds of
nature?
– Socialize with your family?

Can you imagine being
afflicted with uncomfortable
ringing or abnormal sounds
that interfere with sleep?
The Impact Of Noise
Interferes with
communication
 Causes fatigue
 Distracting or irritating
 Reduces morale
or efficiency

Anatomy Of The Ear
The Outer Ear
The Middle Ear
The Inner Ear
Sounds
Several animals can
hear sounds of much
higher frequency,
which is why humans
do not hear special
whistles that may be
heard by dogs.
 Sounds vary not only
in frequency, but also
in intensity.

Decibel
 The
measure of
sound pressure
 The decibel is a
relative measure
 5 dBA exchange
rate
Permissible Noise
Exposure
16
8
6
4
85
90
92
95
3
97
2 1.5
100
102
1
105
.5
110
.25
115
Whisper
90 dB
30
Talking
90 dB
60
Traffic
90 dB
80
Haul
Truck
85
90 dB
Loader
90 dB
86
Lawn
Mower
91
90 dB
Impact
Wrench
103
90 dB
Dozer
90 dB
105
Screens
90 dB
109
Chain
Saw
110
90 dB
Rock
Concert
120
90 dB
Metal
Banging
125
90 dB
Jet
Airplane
90 dB
140
Threshold of pain
12-Gauge
Shotgun 90 dB
165
Hearing Exposure
NIOSH estimates that
30 million workers are
exposed to
hazardous noise
levels
 At present exposure
limits, one in four
workers will develop
permanent hearing
loss

Hearing Exposure
Two Categories
of hearing
Loss:


Temporary
Permanent
Hearing Loss Causes







Wax build up
Measles / Otosclerosis
Aging
Head injury
Drugs / Medicine
Chemicals
Heredity
Signs of Hearing Loss




Fail to catch
words
Ears ringing
Shouting
without
realizing
Trouble
understanding
high
frequency
sounds in
speech
Demonstration of
Hearing Loss
Sound tracks of a male voice,
with no background noise
– Normal
– Loss of 25 dB
– Loss of 40 dB
– Loss of 60 dB
– Normal
Noise Standard
 Action Level 85 dB - Must inform
employees & enroll them in a hearing conservation
program
 Permissible Exposure Level 90 dB Must enroll employee in a hearing conservation
program, use all controls to reduce exposure, must
wear hearing protection
 Dual Protection Level
wear both plugs and earmuffs
105 dB - Must
Eliminating Noise
 Engineering
Controls
– Eliminate or reduce the noise
at the source
– Interrupting the noise path
– Reducing reverberation
 Administrative
Controls
– Change in work schedule
– Quiet areas for breaks
– Job rotation
Hearing Conservation
Program
 Monitoring
system
 Hearing protection
 Audiometric testing
 Training
 Recordkeeping
Audiograms
Audiometric
testing offered
 Qualified medical
provider
 Baseline tests
 Annual testing

Standard Threshold Shift
Hearing changed
by 10 db average
 Employee
notification
within 21 days
 Revised hearing
protection
required
 Further medical
evaluation

Monitoring
Dosimeter
Sound
Level
Meter
Noise Reduction
Rating (NRR)
 Listed
on the package
 How many decibels are blocked
 OSHA subtracts the NRR by 50%
 NIOSH subtracts the NRR by 25%
for earmuffs, 50% for formable
plugs, and 70% for all other plugs
Hearing Protection
Reusable and
Headband Plugs
–
–
–
–
–
25 to 35 dB NRR
Preformed to fit ear
Flexible rubber
Inspect and clean
Replace when hard
or damaged
Hearing Protection
Disposable Plugs
–
–
–
–
25 to 35 dB NRR
Expandable foam
One size fits all
Insert with clean
hands
– If damaged or dirty
throw them away
Inserting Plugs
Hearing Protection
Earmuffs
– 22 to 29 dB NRR
– Foam filled cushions
– Hard to get good
seal
– Works well with
plugs
– Replace when stiff or
worn
Plugs vs. Earmuffs
Advantages
Ear Plugs Good NRR.
Ear Muffs
Disadvantages
Hard to wear.
Get dirty.
Easy to wear. Fair NRR.
Fits everyone. Expensive.
Easily broken.
Conclusion
 Prolonged
noise
exposure causes
permanent hearing
loss
 Hearing loss is
preventable, so
wear your hearing
protection!
It’s Really Pretty
Simple…..

Wear this now...
 Or
wear this later!