3. The employer shall train each employee who is
exposed to noise at or above an 8-hour time
weighted average of 85 decibels in accordance
with the requirements
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4. The training program will be repeated annually
for each employee included in the hearing
conservation program and shall be updated to
be consistent with changes in protective
equipment and work processes
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5. Employer will inform each employee of the
following:
• The effects of noise on hearing;
• The purpose of hearing protectors , the
advantages, disadvantages, and attenuation of
various types, and instructions on selection
• The purpose of audiometric testing and an
explanation of the test procedures.
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6. Hearing losses may result to
• Interference with communication (Must
shout to overcome noise)
• Annoyance
• Altered performance
• Elevated blood pressure
• Sleep disturbances
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7. It is important for the Safety Professional to be
aware of workers off- the-job noise exposures
& causes of their induced hearing loss
• Effects the worker’s overall hearing
• Affects worker’s understanding
• Determines causes of hearing loss
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8. Examples of off-the Job noise that
may cause Hearing Loss
• Loud noise
• Hobbies such as :
• Motorcycles
• Snowmobiles
• Private Airplanes
• Woodworking
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9. To reduce noise exposure:
3 key points:
1. Less Time
2. Further Distance
3. Use Shielding
• Barrier
• HPDs
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10. Four classes of hearing
protection
1. Enclosures (entire head)
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12. 3. Supernatural protectors (canal caps) sometimes
called “banded” hearing protection
• Worn over the head , behind the neck or under
the chin.
• Allows convenience when going in and out of
noisy areas.
• Fitting and using canal caps is similar to fitting
and using other earplugs
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13. 4. Circumaural protectors
(ear muffs)
Passive noise
Reducing earmuff
That compresses harmful
Impulse and continuous noises
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14. With hearing protective devices
• You must offer a Variety of types
• Individuals have preference for certain types
• Depends upon the environments they work and
the activities they do
• Sometimes depends on the shape and size of their
ear canals
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15. For HPDs to be effective, they must first be worn
• Remember the 4 Cs of HPDs:
1. Clean - hands and protectors
2. Consistent- for levels above 85 dBA
3. Correct- insertion
4. Comfortable- so that the worker is not
constantly pulling them out
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16. Ear plugs
ADVANTAGES DISADVANTAGES
• Small > Can introduce dirt
and debris into the ear
• Portable > Can become damp
from sweat and can
• Soft and easy to wear introduce infections/
fungal growth
•Other PPE does not interfere
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17. Premolded Plugs
ADVANTAGES DISADVANTAGES
• Premolded plugs are Sometimes difficult to fit into
relatively easy to insert some ears
and are reusable
• Washable Some people have different
sized canals and must have
• Has stem so that fingers never two sets individually for
touch the flange part that is inserted each ear.
into the ear.
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18. Foam plugs
Checking the fit
• The sound of their voice will seem louder in the
sealed ear.
• If they do not get this sensation, then the ear
canal is not adequately seal.
• Sealing both canals at the same time will cause
the voice to be perceived equally in both ears, or
in the center of the head.
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19. Inspect and Constantly check for:
• Cracked or hardened muff,
• Or a headband that has inadequate tension
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20. Checking the Fit
Perform the “tug test”.
• Gently pull in and out the stem of the
earplug.
• The wearer should feel pressure changes in
the ear canal to confirm have a good fit.
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22. 1. Seal leaks- low frequency sound may pass
through
2. Material leaks- the HPD material
may allow some sound to pass through (not all is
attenuated)
3. Vibration of the HPD- vibration of the noise is
transmitted through the HPD like a piston
4. Bone conduction- vibration of the noise’s
energy is transmitted through the skull
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23. How to Gauge the adequacy of HPDs
• Noise Reduction Ratings
• Regulated by the EPA
• Must be printed on each box and/or package
• Ratings obtained in controlled laboratory
settings
• Controversy on the NRR adequacy
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24. (1910.95 B)
Methods for estimating the adequacy of hearing
protector attenuation
(iii) When using a sound level meter set to the A-
weighting network:
(A) Obtain the employee’s A-weighted TWA.
(B) Subtract 7dB from the NRR, and subtract the
remainder from the A- weighted TWA to obtain
the estimated A- weighted TWA under the ear
protector.
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25. Look at 400% dose
• Dose of 400 % 400%=100 TWA
• Muff NRR is 22 22-7 =15
100-15= 85
Calculate attenuations
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26. % dose of 1.25
1.25 x 100 =125%
D= daily dose if percentage(%)
C = the amount if time an employee was
n
exposed to noise at a specific level.
T = the amount of time the employee can be
n
permitted to be exposed to that level.
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28. Audiometric Testing
Audiometric testing available to all whose
exposure equal or exceed an 8- hour time-
weighted average of 85 decibels.
•At no cost
•Notified that they should avoid high noise
levels both on and off the job at a minimum
of 14 hours.
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29. Mobile test van will obtain audiometric hearing
results within one year of exposure to a time
weighted average of 85dB.
Audiometric measuring will be six months of
employee’s first exposure at above
action level.
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30. Mobile test vans will meet audiometric testing
obligation and obtain a valid baseline audiogram
within one year of an employee exposure at or
above the action level .
Annual audiograms to baseline audiograms
determines whether the audiogram is valid and
whether the employee has lost hearing ability or
experienced a standard threshold shift.
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31. STANDARD THRESHOLD SHIFT
(STS)
• An STS is an average shift in either ear of
10dB or more at
• 2,000 hertz
• 3,000 hertz
• 4,000 hertz
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