Transcript Best Practices in Hearing Conservation

Hearing
Conservation
Theresa Y. Schulz, PhD, LtCol, USAF (ret.)
Announcements
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Welcome
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Introductions
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Introductions
Jeannie Stolzman
Theresa Schulz
3
Introductions
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Safety Professional
Industrial Hygienist
Audiologist
Nurse
Risk Manager
Certified OHC (CAOHC)
Manager/Supervisor
Bureaucrat *
Student
Military / Veteran
4
Topics
Noise And Acoustics
How We Hear
Selecting Hearing Protection
Noise Reduction
Reducing Costs for Hearing Loss
Hearing Protection Fitting Tips
Motivating Workers
5
Noise +
Acoustics
Noise + Acoustics
Hazardous noise exposures occur
On the Job
Off the Job
7
Noise + Acoustics
Noise-Induced Hearing Loss
Causes no pain
Causes no visible trauma
Leaves no visible scars
Is unnoticeable in its earliest stages
Accumulates with each overexposure
Takes years to notice a change
Is Permanent + 100% Preventable
8
Noise + Acoustics
Noise-induced hearing loss is the
most common permanent and
preventable occupational injury
in the world.
World Health Organization
9
Noise + Acoustics
Worker’s Compensation
In many countries, excessive noise is
the biggest compensable
occupational hazard. Cost of
NIHL to developed countries ranges
from 0.2 to 2% of its GDP. NIHL
is on the rise globally. (Source: WHO)
10
Noise + Acoustics
United States Statistics
Most common occupational injury
in the United States. 22 million US
workers are exposed to hazardous
noise at work on a daily basis.
Approx. 8 million Americans
suffer from NIHL. (Source: NIOSH, 2009)
11
Noise + Acoustics
The decibel (dB) scale is a
logarithmic scale, not a linear scale
83 If the noise source is doubled
86
The noise level only goes up 3 dB
92
Represent enormous
increases in noise level
and risk
89
Small
increases
in decibel
level
12
Noise + Acoustics
Time Weighted Average
Permissible Exposure Limits
13
Noise + Acoustics
Time Weighted Average
Permissible Exposure Limits
14
Noise + Acoustics
Time Weighted Average
Permissible Exposure Limits
15
Noise + Acoustics
Regulations in the United States
OSHA
OSHA
MSHA
FRA
29 CFR 1910.95
29 CFR 1926.52
30 CFR Part 62
49 CFR 227/229
Industry
Construction
Mining
Railroads
Permissible
Exposure Limits
90 dB
90 dB
90 dB
90 dB
Action Level
85 dB
85 dB
80 dB
85 dB
Required
Not Required
Required
Required
Annual
Not Required
Annual
Every 3 Years
Required
New Hires/Annual
Not Required
Required
New Hires/Annual
Required
New Hires/Annual
Required @ PEL
Required @ PEL
Required @ PEL
Dual Protection @
105 dB TWA
Required @ PEL
Required
OSHA 300 Log
Not Required
Required
Required
OSHA 300 Log
Noise
Monitoring
Audiometric
Testing
Training
Hearing
Protectors
Recordkeeping
16
Noise + Acoustics
Hearing Conservation Program
Action Level – 85 dB
• Hearing Conservation Program implemented
Permissible
Exposure
Limit
– 90 dB
• Hearing protectors
made
available
Annual protectors
audiometricrequired
testing & training
• Hearing
dB TWA 17
Noise + Acoustics
Noise Measurement Devices
SOUND LEVEL
METER
PERSONAL
DOSIMETER
IN-EAR
DOSIMETER
Sound is measured
immediately in a
specific area
Sound “averaged”
throughout day for
sample employee/job
Collects personal noise
dose – the only real
measure of risk
18
NOISE+AND
Noise
Acoustics
ACOUSTICS
- Hierarchy
~ Hierarchy
of Controls
of Controls
ENGINEERING
CONTROLS
• Buy Quiet
• Vibration Pads
• Enclosures
ADMINISTRATIVE
CONTROLS
• Rotate Workers
• Barriers
• Extended
Breaks
• Isolation
•2nd/3rd Shift
19
PERSONAL
PROTECTIVE
EQUIPMENT
How We Hear
How We Hear
The Auditory System
Chem/Elec
Acoustical
Hydraulic
Mechanical
21
22
How We Hear
High Frequency Sounds of Speech
TH
SH
S
CH
F
T
K
H
23
P
How We Hear
Normal Hearing is Understandable
LOUDNESS
LOUDNESS
24
How We Hear
NIHL Lacks Clarity
25
How We Hear
Audiometric Testing
• A measure HC Program effectiveness
• Measures effectiveness of HPDs
• Catches NIHL in its early stage
• Noise damage can only be determined when
audiograms are compared serially
• A single industrial audiogram cannot identify noise
damage
26
How We Hear
Annual Audiogram vs. Baseline
Worker Profile
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•
•
35 years old
Works in Tire Shop, does not use hearing protection
Early detection of noise-related hearing loss
Employee retrained in the use of hearing protectors
27
How We Hear
Accommodations for hearing impaired
employees
Use Intelligent Hearing Protection
Use hearing aids + electronic earmuffs
Use hearing aids + uniform attenuation
earmuffs
(Hearing aids alone are usually not
feasible protectors)
28
Hearing
Protection
Selection
Hearing Protection Selection
Hearing Protection Selection Factors
• Proper
Select
The
Selecting
Every
Keep
Consider
right
workers
ear
HPDs
care
hearing
job
HPDs
canal
and
thathas
with
can
protector
suitable
its
connected
requirements
maintenance
work
own
with
shape
attenuation
should
other
to their
can
in
and
PPE
HPD
feel
comfortable
for
size
environment
selection
extend
without
noise
life
compromise
environment
and
ofmay
• performance
One protector
Avoid
Ensure
Uniform
Detectable
Cap-mounted
overprotection
proper
attenuation
earplugs
fitHPDs
with
• earmuffs
notmarginal
in
variety
allows
for
Examine
process
satisfy
speech/signals
of for
and
earplug
all
noise
industries
hard
workers
clean
environments
sizes
to
all
be
multiple-use
hear
and
shapes
more
• hats
Offer
Hi-visibility
a
variety
earmuffs
of
naturally
daily
• earplugs
earplugs
Consider
Sized
for
Multiple-position
dark/high
multiple-use
or
banded
earmuffs
traffic
• earmuffs
to meetand
earplugs
Sound
areas
Clean
amplification
varying
forreplace
full-brim
worker
intermittent
earmuffs
ear
cushions
hats
needs
for
noise
workers
on
and
or
• hard
Low-pressure
Dielectric
HPDs
foam
for
preferences
electronic
with
hearing
every
earmuffs
4-6 for
• earmuffs
earplugs
electrical
Ultraslim
for
neckband
smaller
impact
impairment
months
noise.
ear canals
environments
earmuffs
with welding
shields
Comfort
Noise Reduction
Size
Communication
Job Requirements
Hygiene
Use with Other PPE
30
Hearing Protection Selection – Earplugs
PRO
• Comfortable for extended use
• Disposable earplugs available
• Cooler in hot/humid
environments
• Single-use foam plugs can
provide highest levels of
attenuation
CON
• Attenuation highly dependent
upon good fit
• Hygiene issues in dirty
31environments
Hearing Protection Selection – Banded Earplugs
PRO
• Very convenient for
intermittent noise
• Readily available around neck
when not in use
CON
• Lower attenuation than most
earplugs
• Some noise transmission
through band
32
Hearing Protection Selection - Earmuffs
PRO
• Easy to get proper fit
• Good for intermittent noise
• Radio & electronic options
CON
• Can feel hot/heavy with
extended wear
• Compatibility with other PPE?
33
Hearing Protection Selection – Flat Attenuation
PRO
• More natural sounds
• Good for hearing-impaired
workers
CON
• Lower attenuation than most
earplugs
• Costs more
34
Hearing Protection Selection
Speech will
sound more
natural with this
earplug.
8000
4000
2000
1000
500
250
125
50
Attenuation in dB
Variation in
attenuation is
only 5 dB in
speech range
(250 - 4kHz)
63
Frequency in Hz
45
40
35
30
25
20
15
Uniform Attenuation Earplug
10
Conventional Earplug
5
0
35
Hearing Protection Selection – Non-linear HPDs
PRO
• Communication
• Situational awareness
• Impulse noise management
CON
• Training
• Cost
36
Hearing Protection Selection – Intelligent HPDs
PRO
• Amplifies
• Good for hearing-impaired
workers
• Situational awareness
CON
• Cost
37
Communication Solutions
Communication Solutions
• Protection against continuous, intermittent, and
impulse noise
• Connect w/two-way communication radios
• Digital sound processing
• Adaptive talk-through
• Situational awareness
• Active Noise Reduction
• Fit check for protection
38
Communication Solutions
Now: Integrated Bluetooth, In-Ear, ATEX
Sensear
Phonak
CavCom
Howard Leight
39
Hearing Protection Selection – Hazards of Overprotection
Choosing a protector with an NRR higher than
necessary may result in overprotection
• Verbal communication may be hindered
• Warning alarms may not be heard
• Machine noises may be too diminished
• HPDs may be removed
Insufficient Protection
Acceptable Protection
Optimal Protection
Acceptable Protection
Possible Overprotection
40
dB
dB
-85
-85
-80
-80
-75
-75
-70
-70
Worker Exposure
in the Ear With
Protectors
Hearing Protection Selection
In the United States, 76% of
noise-exposed workers need no
more than 10 dB of protection.
90% need no more than 15 dB
of protection.
41
Hearing Protection Selection
Hearing Protection Selection Factors
www.howardleight.com/selector
43
Hearing Protection Selection
Common Objections to Wearing HPDs
“I already lost some of my hearing, “Won’t I get an ear
so why should I wear them?”
infection?”
“Hearing protectors “I don’t need them!
are uncomfortable I am used to the
to wear.”
noise.”
“I can’t hear my
co-workers if I
wear them.”
“Can I hurt my eardrums if I insert an
earplug to deeply.”
“I can always
get fit with a
hearing aid.”
“My machine sounds different.”
44
Noise
Reduction
Rating
(NRR)
Noise Reduction Rating
Noise Level =
100 dB
Noise Reduction Rating =
30 dB
How much noise is
reaching the ear of
the worker ?
That is completely unknown …
(55 – 104 dB)
46
Noise Reduction Rating
Noise Reduction Rating
• A laboratory estimate
of the amount of
attenuation achievable
by 98% of users when
properly fit
• A population-based
rating ― some users
will get more
attenuation, some will
get less
The NRR is only a
population estimate,
not a predictor of
individual attenuation.
47
Noise Reduction Rating
NVLAP-Accredited Labs
Howard Leight
Acoustical Lab,
San Diego, CA
Indianapolis, IN
48
State College, PA
Noise Reduction Rating – Determining an NRR
• 10 human subjects tested in
a simulated industrial room
• Tested with ears open /
occluded at nine frequencies
• Each subject tested 3x
• NRR calculated to be
population average
A test subject in the Howard Leight Acoustical Lab,
49 San Diego, CA, accredited
by the National Voluntary Laboratory Accreditation Program (NVLAP)
Noise Reduction Rating – Determining an NRR
NRR
NRR
Number of test subjects
5
4
3
2
1
14
18 20 22 24 26 28 30 32
19
23 25 27
Attenuation
50
Noise Reduction Rating
De-Rating Methods
OSHA
NIOSH
CSA
NRR ÷ 2
Earmuffs
NRR – 25%
Class
A up to 100
Formable Earplugs
NRR – 50%
B up to 95
(feasibility of
engineering
controls)
Fit
Test
All Other Earplugs
NRR – 70%
51
C up to 90
Noise Reduction Rating –
Attenuation in dB
Real-World Attenuation
≠ NRR
192 users of a flanged reusable earplug ~ 27 NRR
50
NRR = 27 Multiple-Use Earplug
40
30
Retraining
and refitting
resulted in an
average
20
10
14 dB
improvement
for this group
0
-10
52
From Kevin Michael, PhD and Cindy Bloyer “Hearing Protector Attenuation Measurement on the End-User”
Noise Reduction Rating
Biggest Factors in Achieving NRR
2. WEAR TIME
1.FIT
30
A worker who selects an earplug
with an NRR of 30
but then removes that
HPD for just …
effectively reduced his
8-hour NRR to just …
dB
5 min
10 min
15 min
30 min
26 dB
24 dB
22 dB
18 dB
In noise exposures, small intervals of no protection quickly
void large intervals of adequate protection.
53
Noise Reduction Rating
Dual Protection
• For extreme noise environments, dual protection is often
recommended
• To estimate the protected noise level, add about 5 dB to
the higher NRR protector
EARPLUG
+
EARMUFF
=
DUAL
PROTECTION
Example: Earplug = NRR 33
Earmuff = NRR 29
Total Maximum Protection
= 38 dB
55
Noise Reduction Rating
Noise Reduction Rating
• The EPA recently made an announcement about
a proposed change to the Noise Reduction
Rating [NRR]
• This is the first change in hearing protector
regulation in nearly 30 years
56
Noise Reduction Rating
Current NRR Label
80th %
20th %
Minimallytrained
Proficient
Users
Mock-up of New Label
57
Noise Reduction Rating
Three New Labels
LABEL
DESCRIPTION
Conventional
HPD
 Perform lab test with subjects who fit the protector
after brief training
 Estimates the range of protection achieved by
20% and 80% of users
Active Noise
Reduction
[ANR]
• Uses a Microphone-in-Real-Ear [MIRE] method to
estimate protection
• Measured with ANR turned OFF and ON to show
the additional attenuation from the ANR
Level Dependent/
Impulse Noise
Reduction
• Testing will occur over a range of impulse noise
levels. Multiple tests to determine lower and upper
ranges of impulse noise reduction
• Will include two ranges to identify attenuation for
passive and active modes
63
Noise Reduction Rating
Determining New NRR
• 20 human subjects tested in
a simulated industrial room
• Subject trained then fits their
own earplugs
• Tested with ears open /
occluded at 9 frequencies
• Each subject tested 2x
• NRR calculated to be
population average
64
New NRR (NRsa)
80% achieved > 20 dB
20% achieved > 26 dB
Number of test subjects
5
4
3
2
1
11
14
18 20 22 24 26 28 30
19
23 25 27
Attenuation
65
33
Noise Reduction Rating
How to Apply the New Label
Two-number range
displays the
estimated
protection
achievable by
minimally-trained
users [80%] versus
proficient users
[20%].
80%
66
20%
A wider range
indicates greater
variability in the fit
of that HPD.
Smaller ranges
indicate more
consistency of fit.
For example,
earmuffs will
usually have a
tighter fitting range
than earplugs, and
may have a
smaller NRR
range.
Noise Reduction Rating
What Can I Do Now?
Use VeriPRO® fit testing
• Train how to properly fit HPDs
• Select appropriate HPDs
• Document adequate protection
Use QuietDose™
• In-ear dosimetry measures and
documents the noise dose
employee is exposed to during
their work shift
74
Reducing Costs of
Hearing Loss
Reducing Costs of Hearing Loss
In-Ear Dosimetry
Fit Testing
79
Noise
Rating
Field Reduction
Verification
– Fit-Testing
Earplug Fit Testing
Provides an accurate,
real-world picture of your
employees’ hearing
protector effectiveness.
ID if your employees are:
• Getting the right protection
• Need additional training
• Need different earplug
80
As a problem solver:
• Derating Schemes
• One-on-One
Training
• HPD Selection
• NRR Change
Field Verification – Fit-Testing
Real-Ear
Attenuation at
Threshold
(R.E.A.T.)
81
Field Verification – Fit-Testing
Loudness Balance
(Real-Ear Attenuation Above
Threshold)
82
Field Verification – Fit-Testing
Microphone
in Real-Ear
(M.I.R.E.)
83
Field Verification – Fit-Testing
In-Ear Dosimetry
84
Field Verification – Fit-Testing
Audiometric,
1,2
IntregaFit,*
MultiFit
REAT,
freq
1
One
FitCheck*
HPDWellFit
1
QuickFit
1
EARfit*
VeriPRO*
SafetyMeter*
REAT, One
freq
MIRE
Loudness
Balance
Sound booth
Quiet Room
Anywhere
Anywhere
PAR
PAR
Derived PAR
PAR
Any earplug
Any earplug
Modified or
custom
earplugs
Any earplug
COHC
2
Training
included
COHC
Training
provided
Training
included
* Commercially85available
Field Verification – Fit-Testing
"I know how to
better fit my
earplugs now."
"I found a more
comfortable fit. It
was very
beneficial."
"Feel like am
protected now!"
"Learned A LOT
about best
earplugs for me"
"I had no idea I was
not using my
earplugs correctly."
"I was amazed
with the results
after being shown
the proper way to
use earplugs.
89
"Recently had
threshold shift"
"Found better
earplugs"
"Very glad I did
the fitting test.
Now I know the
correct way to fit
my ear plugs.”
In-ear dosimetry measures/records
worker’s actual noise dose, with and
without protection
Provides real-time monitoring and
alerts when worker
approaches/exceeds safe limits
Only metric with direct potential to
measure and prevent further
progression of occupational hearing
loss
90
Reducing Costs of Hearing Loss
91
Research
> Alcoa
Works
Reducing Costs
ofIntalco
Hearing
Loss
Mean Hearing Threshold (2k, 3k, 4kHz): 2000 – 2007 (N = 46)
Mean hearing threshold (2,3, and 4 kHz)
Employees using
continuous
in-ear
starting in 2005
Employees
using continuous ESP
starting indosimetry
2005
2000 - 2007 (N=46)
50
ESP Introduced
Mean HTL 3,4,6kHz
45
trend line
40
35
30
25
20
15
10
5
0
2000
2001
2002
2003
2004
Year of 92
test
2005
2006
2007
Reducing Costs of Hearing Loss
Preventive Action after NIHL
In practice, an OSHA-recordable STS is not a preventive action ….
It is documentation of a hearing loss after the fact.
How soon will an employee suffering NIHL be re-fit / re-trained ?
“Best case scenario” per Hearing Conservation Amendment
In-ear dosimetry “worst case” scenario …
1 Day
0
2
• Retest
• Audiometric test
4
6
8
10
Months
93
12
14
• Notification
16
Reducing Costs of Hearing Loss
OSHA Alliance: Best Practice Bulletin
www.hearingconservation.org
Additional Information
www.hearforever.org
94
Reducing Costs of Hearing Loss
PROS
- Estimate
CONS
Measure
- Cost
- NRR obsolete
- Time Investment
- Fulfills OSHA compliance
- Not standardized
- Eliminates need for de-ratings
- Medico-legal cases
- Delineates non-occupational
- Eliminates double protection
- Provides employee feedback
95
Reducing Costs of Hearing Loss
Off-job + On-job
96
=
STS
Hearing
Protectors +
Fitting Tips
Fitting Tips
0 dB
0 dB
33 dB
EAR #1
EAR #2
EAR #3
How much protection?
98
Fitting Tips
Good Fit vs Bad Fit
90
Attenuation in dB
80
70
Max Good Fit
NRR = 33dB
Max Poor Fit
NRR = 0dB
60
50
40
30
20
10
0
-10
99
8000
6300
4000
3150
2000
1000
500
250
125
Frequency in Hz
Fitting Tips
Roll-Down Foam Earplugs
1. Roll
entire earplug
into a crease-free
cylinder
2. Pull Back
pinna by reaching over head
with free hand, gently pull top
of ear up and out
3. Insert
100
earplug
well into
ear canal
and hold
until it fully
expands
Fitting Tips
101
Fitting Tips
Multiple-Use Earplugs
1. Reach
While holding the stem,
reach hand overhead
and gently pull top of ear
up and back.
2. Insert
Insert earplug so all
flanges are well inside the
ear canal.
3. Fit
If properly fitted,
only the stem of
the earplugs
should be visible
to someone
looking at you
from the front.
102
Fitting Tips
Visual + Acoustical Checks
1. Visual Check
2. Acoustical Check
The earplug should sit well
inside the ear canal and not
stick out.
Cup hands over ears and
release. Earplugs should
block enough noise so that
covering your ears with hands
should not result in a
significant noise difference.
103
Fitting Tips
“How well can users predict their
attenuation after a short fit-testing
training session?"
104
Fitting
3 of 4 Tips
workers ID’d good fit vs poor fit
Ability to Predict Noise Reduction
100
Accuracy of estimate
(75% were within one category of actual PAR)
47%
90
80
70
60
28%
50
14%
40
30
20
10
0
Same Category
One off
Two off
105
Three off
Four off
Fitting Tips
Earmuff Instructions
1. Place earcups over
each outer ear
2. Adjust the headband
by sliding the
headband up or down
at the attachment
buttons
106
3. The ear cushions
should seal firmly
against the head
Fitting Tips
Fitting Instruction Posters
107
Fitting Tips
FAQ: Earmuffs + Safety Eyewear
In our facility, several noisy
areas require safety
eyewear as well as
earmuffs.
Can earmuffs be worn over
safety eyewear without
affecting attenuation?
Attenuation is
impacted significantly
by thick-framed
eyewear.
Affect on Attenuation
Thin Frame (1-2 mm)
0 dB
Medium Frame (3-4 mm) 2 dB
Thick
5 dB
108Frame (5-6 mm)
Fitting Tips
FAQ: Dual Protection
At our facility, we are
exposed to extreme noise
levels and wear both
earplugs and earmuffs.
How much reduction in
noise level can we expect
from dual protection?
To estimate protected
noise level, add 5
dB to the higher
NRR protector.
Max® earplug
33 dB
Viking™ earmuff
29 dB
Maximum
Protection 38 dB
109
Training +
Motivation
Training + Motivation
Personalize Hearing Loss
Show, Don’t Tell
• Provide copy of annual
audiogram to worker
• Use personal examples to
demonstrate consequences
of hearing loss
• Ask questions:
• What is your favorite sound?
• What sound would you miss
the most if you couldn’t hear?
• What sounds connect you to
people and your environment?
116
Training + Motivation
Demonstrate Future Risk
Training Materials
• www.hearforever.org
• www.hearingconservation.org
• http://adl.grc.nasa.gov
• www.cdc.gov/niosh/topics/noise
• www.dangerousdecibels.org
www.hearforever.org/
ORNL2011
117
Training + Motivation
118
Training + Motivation
Send Clear Message On + Off Job
HC Part of Everyday Life
• Include recreational hearing
conservation in annual
training
• Provide extra HPDs for
home use
• Promote Hearing
Conservation at
company/family events
119
Training + Motivation
Remove Barriers to HPD Use
Make HPDs Available
• Highlight “where to find
HPDs” in annual training
• Make sure HPDs are wellstocked and accessible
• Include group of workers in
selection process for
increased acceptance
• Offer wide variety to match
comfort, job requirements
120
Training + Motivation - HCP Requirements
Training + Motivation
•Health effects of
noise
•Purpose of hearing
protection
•Advantages/
disadvantages of
various types of
HPD’s
•Selection, fit, use
and care of HPD
•Purpose and
procedures of
audiometric testing
121
122
www.youtube.com/hlhearforever
123
Hearing Loss Due To
Noise Exposure Is …
Painless
Permanent
Progressive
… and very Preventable!
124
Make Hearing
Conservation Part of
Your Everyday Life
125
Download today’s
presentation at
www.hearforever.org/
ORNL2011
126