Download NOISE and YOUR JOB

NOISE
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Noise - what is it?
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Unwanted sound
• sound is vibrations in air
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Sound Pressure Level
• decibels (dB) - sound
loudness
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Frequency
• hertz (Hz) - vibrations
per second
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Good human ears
hear sounds between
20 to 20,000 Hz.
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Types of Noise
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Continuous
• same noise level over long periods
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Intermittent
• periods of quiet interrupted by noise
• most noise exposures are intermittent
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Impact or impulsive
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• nail gun
Most jobs have combinations of all noise
types
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Is noise a big problem?
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28 Million Americans affected
• NIOSH says 2.5 million workers/year are affected
• Over 500,000 construction workers are overexposed.
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50% of construction workers may have some
job-related hearing loss
33% of hearing loss is from NIHL
A 25 year old construction worker has the
hearing of a 50 year old without noise exposure
Once hearing is gone, it is lost forever
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Source: Construction Safety Association of
Construction Workers
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What does that mean
to our workers
How do we protect
them
Hierarchy of controls
Common exposures
– jackhammer
– power tools
– heavy machinery
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You
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What does that mean to you?
Loss of hearing through aging
(presbycusis)
Born with ~ 40,000 cilia
in ear canal
Common Exposures
– iPods, headphones
– loud music/concerts
– hunting
– other
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Decibels
Noise levels are measured in decibels (dBA)
• A small increase in decibels equates to a large
increase in noise (logarithmic)
• An increase of just 3 dB doubles the amount of
sound 88 dB can do twice as much harm to your
ears as 85 dB. An increase of 10 dB means it is
10 times louder
• Typical levels:
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65- normal conversation
75- busy street corner
85- background noise on a construction site
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How Do We Hear?
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Outer ear collects
sound and vibrates
eardrum
Eardrum vibrates
bones in middle ear
Bones transmit
vibrations to cochlea
(inner ear)
Cochlea hair cells are
connected to auditory
nerve that runs to the
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brain
Effects of Noise
•
Temporary Threshold Shift (TTS)
• temporary hearing loss
• early sign of a hearing problem
• recovery within hours after exposure
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Effects of Noise
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Permanent Threshold Shift
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permanent hearing loss
destroys hair cells
no treatment or cure
gradual
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Effects of Noise
•
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Tinnitus - ringing in the ears
Non-auditory problems
• Constant state of “alert”
• Disturbed sleeping patterns
• Increased blood pressure
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Presbycusis
• hearing loss from aging
• may be compounded by excess noise
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Effects of Hearing Loss
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Hearing loss makes it harder to
communicate on the job, with friends
and family, especially in noisy places
like jobsites and restaurants
Hearing loss can make it difficult to
hear warning signs like back up alarms
or traffic on a street
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Other Health Effects
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Make you feel tired/fatigued
Heighten nervousness
Raise in blood pressure
Increase risks of heart problems
May also effect sense of balance
These effects are permanent
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What can you do?
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Turn down the volume
– When listening to music on earphones at
a medium volume, the noise generated
reaches up to 100dBA
– Loud enough to cause permanent
damage after just 15 minutes/day
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Use hearing protection
Walk away
3 Foot Rule
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OSHA Requirements
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Construction 90 dBa
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General Industry 85 dB
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Hearing Conservation Program (1926.52)
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OSHA Table D-2 Permissible
Noise Exposures
Duration per day, hours
Sound Level dBA
(slow response)
8
90
6
92
4
95
3
97
2
100
1.5
102
1
105
.5
110
.25 or less
115
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Task-Based Method
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ANSI A10.46-Hearing Loss Prevention in
Construction and Demolition Workers
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When equipment or tasks expose workers to
sound levels exceeding 85 dBA, engineering
or administrative controls should be
implemented
Where controls are infeasible or fail to
reduce sound levels below 85 dBA, HPD’s
shall be provided and used by employees
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Effective Hearing
Conservation Program
1.
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3.
4.
5.
6.
7.
Monitoring of employees’ noise
exposures,
Engineering, work practice, and
administrative controls,
PPE
Employee training and education
Baseline and annual audiometry,
Procedures for preventing further
occupational hearing loss
Recording Keeping
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Hearing Protectors
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Ear Plugs
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Semi-Inserts
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Ear Muffs
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Attenuation
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Ear Plugs
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Formable
Pre-molded
Custom-molded
Pros
• cooler in hot weather,
cheaper
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Cons
• attenuation varies with fit
• easier to lose
• hygiene problems
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Ear Plugs
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To fit correctly, ear
plugs must be inserted
snugly into the ear
canal.
Make sure the foam
plugs are rolled up
tight and is crease
free. Use the Roll
model for practicing.
Pull back gently on the
ear with your opposite
had to straighten out
the canal while
inserting the plug.
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Proper Fit
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Ear plug is snug in
the ear canal
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Incorrect Fit
•
Ear plug is not in
snug and protection
level is much lower
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Semi-Inserts
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Ear plug connected by
headband
Insert into the canal or
cap over it
Intended to be worn
for short duration
Pros
• easier to take on and off
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Cons
• uncomfortable for
extended use
• smaller attenuation
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Ear Muffs
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Plastic cups attached by
headband
Pros
• easier to fit to most
people, more consistent
attenuation than plugs,
can be fitted hardhats
Cons
• heavier/hotter than
plugs,
• headband pressure can
make long wear
uncomfortable
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