NOISE HAZARDS AWARENESS CURRICULUM

Produced by the
Hunter College Center for Occupational and Environmental Health
1999





NOISE HAZARDS AWARENESS CURRICULUM

TABLE OF CONTENTS

Section:
Introduction
Noise Reduction and Hearing Conservation Policies
The Impact of Noise on Health
Reducing Noise Hazards at the Worksite
Selection and Use of Hearing Protection Devices

The Role of Audiograms in Hearing Conservation



Acknowledgments

The Noise Hazards Awareness Curriculum was developed by the staff of the Hunter College
Center for Occupational and Environmental Health. Its authors include Robin Gillespie M.P.H.,
Paula Knudson, C.I.H., and Amy Manowitz, M.P.H.. The awareness curriculum was made
possible through a grant from the New York State Occupational Safety and Health Education
Program (Contract #C008406, September 1998 - July 1999).

Readers are free to copy and distribute the awareness curriculum materials for noncommercial
purposes as long as the credits listed on this page are retained.

Thanks to Susan Shephard and Robin Dewey for permission to adapt parts of their training
curricula Noise at Work, produced at the Occupational Health Surveillance Program,
Massachusetts Department of Public Health. The text on training methods was adapted from
material originally produced at the Labor Occupational Health Program, University of California
at Berkeley.

The ear image was reprinted by permission from Professor Sally Lusk, PhD, RN, FAAN, the
University of Michigan, copyright University of Michigan.

The speech banana was reprinted with permission of “Where do we go from hear?”
(www.gohear.org)

Kk KKK

For more information, write or call us:
Hunter College Center for Occupational and Environmental Health
425 East 25th Street
New York, NY 10010
Phone: (212) 481-8790
Fax: (212) 481-8795

E-mail for Amy Manowitz, Project Director:
amanowit@hunter.cuny.edu


SSeN6NNanaos0—_0—“@—0u>—=$@oomaows$SoO S050
AWARENESS CURRICULUM INTRODUCTION
e6e—soorO————————————————————————————————————————

Overview of Curriculum
This curriculum is designed to provide basic awareness information on noise control and hearing
conservation. It includes the following:

° Scripts covering five modules:
Topic Time Allocation
Noise Reduction and Hearing Conservation Policies 5 minutes
Health Effects of Noise 10 minutes
Reducing Noise Hazards 15 minutes
Selection and Use of Hearing Protection 20 minutes
The Role of Audiograms in Hearing Conservation 10 minutes
° A description of the teaching objectives for each module and a description of what
participants should be able to do following training;
. Notations in brackets where company or department-specific detail should be added;
° Suggestions for activities to help expand and reinforce the material and skills learned in

each section.

Teaching Approach and Methods

The script is designed to guide training, not simply to be read aloud. You should adapt it to your
workplace by adding in specific details and policies. Although the curriculum can be used in a
basic lecture format if time is limited, a variety of participatory learning activities are included in
the script and in the “Suggested: Additional Activities” section of each module. In some cases,
these activities will require more time than indicated in the list above, but if you can devote the
time they will also encourage participation and develop important health and safety skills

The participatory activities include brainstorming, class discussion, and different types of small

group exercises. The goal of all these activities is to get students to participate in the class and

apply what they learn to their work. Participatory teaching methods are based on the basic

principles of adult education theory:

e Adults expect to learn information that is relevant to them and has immediate application to
their lives.

¢ Adults have enormous experience from work and their private lives that should be drawn into
the classroom discussion.

¢ Learning is more interesting when concrete examples are drawn from the actual workplace.

¢ Adults learn well from each other. A good class set up keeps participants facing each other
and working together.

¢ Adults learn best when they are actively engaged, when they learn by doing.

¢ Adults want to learn. If the conditions are right, training should be effective and enjoyable.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM INTRODUCTION - I



es=@aaaeeesss——seoooooooS=$mSS

Class discussion

Class discussion is the most frequently used participatory method in this curriculum. The entire
class participates by trying to answer a question. The instructor guides the discussion, exploring
the issue with participants but normally not supplying the answer. The instructor also may add
background information and further explanation after the question has been answered.

Here are some tips for leading a successful discussion:

. Don't read the answers from the script word-for-word.
° Make the discussion relevant by drawing on examples from students’ experience.
. Include all the participants in the discussion. Address the question to the group as a

whole first so everyone has a chance to think and respond. Then wait a short time for
someone to answer (some educators recommend 4-5 seconds). If no one answers, you
might want to call on someone in order to keep the discussion going.

. Feel free to use different (or extra) questions. The more relevant you can make the topic,
the more your students will learn.
° Use the board often -- even when the curriculum doesn't specifically tell you to. Make

lists. Draw pictures and diagrams.

Brainstorming

Brainstorming is another technique used in the modules. The class is asked to generate as many
ideas as possible on a specific topic. With brainstorming, no idea is wrong or stupid; all ideas are
encouraged. The instructor records all ideas on the board for everyone to see and discuss.

Small Group Activity
A third technique recommended for this noise hazards curriculum is the small group activity. To
conduct any small group activity:

° Break the class into small groups.

. Distribute the handouts which relate to the activity.

. Explain the activity and tell people how long they will have to complete it.

. Ask each group to pick a recorder. Explain that the recorder will be responsible for taking
notes and will report later to the whole class on the group's work.

° Have each group go to a separate room, or a separate part of the main classroom, to
complete the exercise. After the scheduled time is up, bring the whole class back together.

° Ask the recorder chosen by each group to explain how that group did the activity and

solved the problems or answered the questions. Then, ask the whole class to comment.
Make sure that there is enough time to discuss why each group came up with its
conclusions. Add any information that you think is relevant.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM INTRODUCTION - 2



Scene
tok kok

Health and safety training does not have to be routine and by the book. It should be designed to
answer real questions and help people solve problems as well as to achieve compliance. In
particular, required annual training tends to be too familiar by the second or third go-around for
anyone to take it very seriously. As you use this curriculum, try to adapt it to each group you
train, and vary it somewhat year to year. Keep notes of what changes you have tried, and refer to
them before you teach again. It is a good idea to have training participants evaluate the content
and process of the workshop to help improve it. Keep a list of problems, questions, ideas and
solutions that arise over the course of the year and use them to update your training. Take
pictures of improvements to illustrate your workshops.

Above all, remember that if the trainer is bored, the trainees will be too. Keep the workshop
content and activities interesting for you, and you are more likely to provide effective training.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM INTRODUCTION - 3




NOISE REDUCTION AND HEARING CONSERVATION POLICIES

SN

~S

Vv

Teaching Objectives
* to review company policies

Learning Objectives

Participants will be able to:

* name the key person responsible for the hearing conservation program

¢ describe the role of management, individual workers [and those with specified
responsibilities if appropriate] in running a successful hearing conservation program

¢ _ state three actions or behaviors he or she is responsible for

SAY

The goal of this company’s hearing conservation program is to protect all workers from
hearing loss and to limit noise to safe levels. Management is committed to providing staff
time, funding, and technical support to make this program a success. Employees from all
areas are encouraged and expected to participate in this process. Participation means
wearing hearing protection where recommended or required, pointing out new or
unidentified sources of noise, providing suggestions for improvements, attending training
and receiving audiograms as scheduled. Some people have additional responsibilities:

SHOW OVERHEAD - List of phone numbers and work locations of people with
hearing conservation program responsibilities

SAY:

- _ [Name and title] is responsible for coordinating all hearing conservation program
activities.

+ These are the names of who to contact with questions, complaints or suggestions
about: noise identification and control; audiograms and hearing loss; hearing

protection; and training. [If possible, provide names from each shift and department.]

SHOW OVERHEAD - List of company policies

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM POLICIES - 1


v SAY:
In our facility, we have specific hearing conservation and noise reduction policies that
cover the following areas:

* How we find out what areas are too noisy: An initial noise survey, including
sound level measurements, has been [will be] carried out throughout the facility. It
will be repeated in noisy areas every [describe your schedule here], and wherever
work conditions change or noise complaints occur.

* What we do to reduce noise exposures: Noise will be controlled at the source
wherever possible by improving equipment selection and repair, by process
improvements and eliminating or enclosing sources of noise.

[Describe any specific policies not covered in other sections, for example, if you
have a policy that sets noise specifications for new equipment purchases and new
process development or a plan for replacing noisy equipment and improving noisy
processes]

° What we do for workers in noisy areas: As you will hear later in the session,
testing, training and hearing protection are provided and required when noise cannot
be eliminated or reduced to a safe level.

¢ How workers’ hearing will be tested: Audiograms are provided to all workers
exposed above 85 dBA. [State which other workers, if any, are offered testing.] This
process will be described later.

¢ How hearing protection devices are selected, used, maintained and replaced:
This will also be discussed during this training program. The most important policy
item is that hearing protection is required to be worn by everyone exposed at or
above 85 dBA and in all noise hazard areas. Hearing protection is available to other
workers who request it for work [and home] noise exposures.

¢ What can be done for workers who have trouble hearing: Workers who
experience hearing loss for any reason — whether or not they are exposed to noise at
work — should contact [provide name and phone number here] with any problems or
concerns. If needed, this person can help you, or refer you to someone who can help
you, with:
-- further hearing evaluation
-- work accommodations
-- temporary or permanent job reassignment
-- workers’ compensation information
-- hearing protection device selection and use

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM POLICIES - 2


> SSS

Si SAY
You can read the complete policy for our hearing conservation program that is in [state
where written policy is found]. If you think anything is incorrect, missing or not being
carried out as planned, please contact [name of appropriate person] with your ideas.

= ADDITIONAL SUGGESTED ACTIVITIES
+ Ask if anyone has had problems or concerns about any of the areas described.
+ _ Ifyou are training a safety committee or any group likely to want to contribute to
program development and implementation, consider breaking into smaller groups at
this point to discuss what the policies in each area should cover, what problems they

have encountered or expect to encounter, or ideas for implementing an effective
program.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM POLICIES - 3




Company Policies

Our written policies cover:
How we find out what areas are too noisy
What we do to reduce noise exposures
What we do for workers in noisy areas
How workers’ hearing will be tested

How hearing protection devices are selected,
used, maintained and replaced

What can be done for workers who experience
hearing loss

Policy # 1



Contacts

Overall HCP

Noise identification
and control

Audiograms and
hearing loss

Hearing protection

Training

Policy #

2



a

THE IMPACT OF NOISE ON HEALTH

See ee

® Teaching Objectives
* To review how noise causes hearing loss
* To describe other effects of noise in the workplace

® Learning Objectives
Participants will be able to:
* — explain how noise affects hearing
* state three ways noise affects workplace health and safety, other than hearing loss
* — describe three other contributors to hearing loss (e.g. aging, specific diseases, off-the-
job exposures)

~~

ASK
What is the problem with noise at work? What does it do that is so bad?

B

LIST participants’ answers (without criticism), then indicate which you will be covering
in this section.

Expected answers:

¢ makes people lose their hearing
¢ makes it hard to communicate

¢ _ is irritating

N

SAY
Noise is a problem at work mostly because it can cause hearing loss. Noise is the most

common cause of hearing loss, and occupational noise is responsible for the majority of
noise-induced hearing loss.

v

SHOW OVERHEAD - Terms

N

SAY

Let’s define a few terms before we get started. Technically, noise is a sound wave

produced by vibration. Noise is described in terms of:

* amplitude -- the amount of sound, which the ear perceives as loudness. Loudness is
measured in decibels. Decibels are calculated on a special scale called a log scale;
loudness doubles every three decibels. So 93 decibels is actually twice as loud as 90
decibels.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEALTH EFFECTS - 1



DN ee eee. ee

Vv

<

¢ frequency and wavelength -- how high or low the sound is, also described as pitch.
e duration -- how long the sound lasts

SHOW OVERHEAD - Noise chart
e For reference, here is a diagram of the levels of noise experienced in various
situations.

-- A quiet room normally has background noise around 40 dB.

-- Conversation or an air conditioner raises the level to 60 dB.

-- Acar ata 50 feet is louder than conversation.

-- Notice that a diesel truck at the same distance is loud enough to cause damage if
you’re continually exposed. Trucks have been shown to cause hearing loss in
drivers who leave the window open -- worse in the left ear than the right.

-- Machine exposures routinely produce unsafe levels that are not safe: Milling is
85dB, a newspaper press or a lawnmower is 95 dB, pneumatic equipment gets up
to 115 dB.

-- Movies and music frequently generate 110 dB. Even a personal stereo headset
set above 5 can reach this level, causing damage after regular use for less than
fifteen minutes per day.

SHOW OVERHEAD - Anatomy of the ear

SAY

¢ So how does noise lead to hearing loss? This is a picture of the ear. Sound waves
travel through the ear canal -- vibrating the ear drum which passes the vibration
through the middle ear along to the cochlea -- the snail-shaped part of the inner ear.
The tiny hair cells lining the cochlea bend in response to vibration. This transmits a
signal to the brain.

¢ Hearing loss is like taking a shortcut across a lawn. Your feet bend the grass down,
and it takes a while for the blades to spring up after you pass. The more you walk, or
the more heavily, the longer it takes for the grass to recover. And what happens if you
walk over the same shortcut repeatedly, for days or weeks or years? The grass is worn
away.

¢ — Just like grass, it takes time for the hair cells to bend back and be able to respond to
vibrations again after they have responded to noise. Loud noise forces the hair cells to
bend so much they may require quite a lot of time to recover their upright position.
The louder the noise or the longer the exposure, the longer the recovery time. The
resulting short term hearing loss, called a temporary threshold shift, can last for hours.

oOo ?50$Saa oo
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEALTH EFFECTS - 2


0°00

* — Ifexposure is severe enough, you may not recover completely before the next work
shift begins. People differ in their ability to recover; it is affected by genetics,
chemical exposures (including medications), age, and other noise exposures.
Permanent hearing loss occurs when the hairs are so damaged they cannot recover,
like the grass that has been trampled over too many times.

¢ Unfortunately, the sounds we rely upon for understanding speech occur in the
frequency range most affected by noise. The ear is particularly sensitive to noise, and
noise damage, around 4000Hz where consonants like T and S fall. When you cannot
hear consonants, even if people “speak up” and increase their overall volume, you
cannot understand parts of the words. This is why hearing loss is hard to correct with
hearing aids.

~~

ASK
How much noise is too much?

/ SAY
* OSHA restricts noise exposure to 90 dB(A), averaged over an eight hour workday.
Other experts believe that 85 dB is loud enough to cause permanent damage after
long-term exposure during an eight-hour work day. Some very sensitive people may
lose hearing if regularly exposed to less than 85 dB(A).

* OSHA requires employers to cut the exposure time in half with every five decibels of
increased noise. However, noise intensity actually doubles with every three decibels,
so National Institute for Occupational Safety and Health recommends that exposure
time be halved with every three decibels. Even one second of noise exposure around
140 dB can cause permanent damage.

~~

ASK
Some would argue that we’ll all lose our hearing eventually, so why bother about noise?

¥ SAY
¢ While many people lose some hearing as they age, noise greatly increases the risk of
hearing loss at all ages. Approximately one-third of the 20 million cases of hearing
impairment in the American population are attributed to noise. And according to
NIOSH, occupational noise exposure is the most common cause of noise-induced
hearing loss.

¢ Ofcourse, occupational noise is not the only cause of hearing loss.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEALTH EFFECTS - 3


ey ASK
What off-the-job noise exposures also contribute to hearing loss?

Expected answers:

* target shooting and sometimes hunting

* — listening to loud music — concerts, stereos or through earphones
* using power tools

* using powered lawnmowers

* — seeing movies in movie theaters

* frequent travel in airplanes

N

SAY

* — If you spend a significant amount of time doing any of these noisy off-the-job
activities, hearing protection should be used. Also, equipment maintenance and
regular audiograms are recommended, just as for work exposures.

~~

ASK
What else can lead to hearing loss besides noise?

SHOW OVERHEAD - Other causes of hearing loss

~

SAY

A few chemicals found in the industrial environment can damage hearing. Workers
exposed to both chemicals and noise may be at higher risk. Some medicinal drugs can
cause hearing loss. Infections and brain tumors can affect hearing by damaging the inner
ear, the acoustic nerve, or the brain. Injuries to the head or ear may also cause hearing loss.

~~

ASK
Do you think noise affects your health in any other way?

Y

SHOW OVERHEAD - Other health effects

—~

SAY
* Noise as low as 75 dB may also contribute to health problems.

-- The body can respond to excessive noise with increased muscle tension,
breathing rates and heart beat, and constriction of the blood vessels. The response
is similar to a startle or stress response.

-- Noise exposure may lead to longer-lasting changes in a worker’s blood pressure,
blood cholesterol, stomach lining or immune function.

-- The long-term effect of noise on health has not been completely determined.

—————
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEALTH EFFECTS - 4



eG6CNeeo0ee eee

¢ Finally, noise is also a problem because:
-- it can create serious safety hazards by masking alarms and other warning sounds;
-- it can discourage communication between workers because shouting is hard to do
and hard to listen to; and
-- noise makes it harder for people with hearing loss to get information from the
sounds frequencies that they can hear.

¥ SAY

* Many people do not take potential hearing loss seriously. It is true that hearing loss
doesn’t kill you but hearing loss can be very traumatic. It interferes with family life,
social exchanges, the enjoyment of music and other important activities. It can
contribute to depression and emotional conflicts.

* The bottom line is that repeated or prolonged exposure to noise can permanently
damage hearing and cause other harmful effects. The best way to prevent all the
hazards caused by noise is to reduce noise in the work environment. The best way to
protect your hearing from any remaining noise is to wear well-fitted and well-
maintained hearing protection that suits your exposure level and work activities.
Noise reduction and hearing protection will be discussed in the next sections of this
training.

ts ADDITIONAL SUGGESTED ACTIVITIES
¢ Play a tape that simulates hearing loss.
¢ — Invite a person with work-related hearing loss to speak to the group about how their
hearing loss has affected their life at work and at home.

ea.
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEALTH EFFECTS - 5





Noise terms

Amplitude:
loudness, measured in decibels

Frequency:
how high or low the pitch is

Duration:
how long the sound lasts

jealth effects #


Sound intensities

FIGURE 1, Typical A-weighted noise levels in decibels (dBA)*

dBA

120

1104 ROCK-N-ROLL BAND

TEXTILE LOOM
100
NEWSPAPER PRESS POWER LAWN MOWER (at operator's ear)
90
DIESEL TRUCK 40 mph (at 50 ft.) MILLING MACHINE {at 4 ft.)
GARBAGE DISPOSAL (at 3ft.)

PNEUMATIC CHIPPER (at 5 ft.)

PASSENGER CAR 50 mph (at 50 ft.) VACUUM CLEANER

CONVERSATION (at 3 ft.) WINDOW AIR-CONDITIONING UNIT (at 25 ft.)

QUIET ROOM

“The decibel is a logarithmic measure of sound intensity; the “A-weighted scale" is used to weight the
various frequency components of the noise to approximate the response of the human ear.

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES / PUBLIC HEALTH SERVICE

Health effects# 2




Other causes of
hearing loss

¢ Chemicals

« Diseases

¢ Injuries



Other effects

dilation of

; Ve the pupil

secretion of
thyroid
hormone

secretion
ot adrenalin

secretion of
adrenalin

cortex
hormone

: movements of
the stomach
and intestines

muscle reaction

constriction of the
blood vessels

Health effects# 5





REDUCING NOISE HAZARDS AT THE WORKSITE

G

Teaching Objectives:
¢ Review types of engineering and administrative controls

iy

Learning Objectives:

¢ describe at least one engineering control method to reduce noise at the source

¢ describe at least one engineering control method to reduce noise along the pathway
¢ describe at least one engineering control method to reduce noise at the receiver

¢ explain at least one administrative control to reduce noise

* state the company plans for reducing noise

? ASK
Do you think you’re exposed to hazardous levels of noise here at work?

Expected answers:

¢ It must be hazardous because I have to wear hearing protection
¢ It’s probably over 85 dBA

¢ In some areas it’s really loud

¢ Not at work, but at home

=~

SAY
. We do have some areas in our facility where the noise levels are considered
hazardous. You might have seen [name people involved in taking noise
measurements] taking noise measurements. To make it easier for you to see where
the problem areas are, we have used the information collected to develop a noise
hazard map of the entire facility. [Review the noise hazard map.]

¢ Keep in mind, even if a workplace is not noisy enough to present a risk for hearing

loss, there may be enough noise to cause safety or communication problems.
We’ve also marked these areas on the map.

= SHOW OVERHEAD - Noise measurements for the group of participants
v SAY

e As you can see, the level of noise in your [department or work area] is [state levels
of noise measured, area and personal noise measurements].

EEE
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 1



SS oOoOoOoansanaawa#anaomawaqxsnmpayanmanapapampapapSwsS

° According to OSHA, when workers’ daily noise exposures are at or above 90 dBA,
employers have to take action to try to reduce noise levels by using engineering or
administrative controls. But many experts, such as NIOSH, recommend controls be
implemented when workers are exposed to levels at or above 85 dBA - which is
significantly lower than OSHA’s requirement. At our facility, we are following the
NIOSH guidelines.

> SHOW OVERHEAD - Engineering and administrative noise control definitions

? ASK
What are noise controls?

v SAY
NIOSH defines engineering controls as “any modification or replacement of equipment,
or related physical change at the noise source or along the transmission path that reduces
the noise level at the employee’s ear.” Administrative controls are defined as any
change in work assignment, production schedules or policy decisions that reduce
workers’ noise exposures.

= SHOW OVERHEAD - Source/path/receiver

v SAY
Simply put, we can reduce workers’ noise exposures by making engineering or
administrative changes at the noise source, along the pathway, or at the worker.

What we’ll do now is discuss these approaches to noise control in more detail. Then
we’ll talk about the types of controls we are working on [or have already put into place]
in our facility.

v SAY
The best method of controlling a noise problem is to minimize the noise at the source.

> SHOW OVERHEAD - List of noise controls at the source

v SAY
° When attempting to control noise at the source, you can look at ways to replace or
modify equipment, processes or materials and at ways to reduce vibration. You can
also set up a maintenance program that regularly checks equipment. to repair or
replace worn, loose or unbalanced parts of machine. Enforcing a “buy quiet”
equipment purchase policy for any new equipment or when modifying existing
equipment also helps reduce noise at the source.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 2



Vv

SN

Vv

SS

Vv

SS

~

Vv

. Let’s go over some specific examples. A process can be made less noisy by
replacing hydraulic presses for mechanical pressses.

SHOW OVERHEAD - Example of quieter process (substituting pliers for hammer)
[Ideally, use an example from your facility.]

SAY
A simple example of a quieter process, shown in this overhead slide, is to use a pair of
pliers to bend a strip of metal rather than using a hammer.

Replacing steel tires with rubber tires is an example of using a quieter material to reduce
noise.

SHOW OVERHEAD - Example of vibration isolation (Ideally, use an example from
your facility. ]

SAY

Reducing vibration can also reduce excessive noise at the source. A vibration isolator is
an elastic material which supports the vibrating machine and isolates it from the
surrounding structure. This example shows how either the machine or the working area
can be vibration isolated with the use of heavy springs.

SHOW OVERHEAD - Vibration isolation materials [Ideally, use an example from
your facility.]

SAY
Vibration isolators are made of various materials and come in various shapes. Vibration
isolation materials can be applied to the linings of tumbling barrels, chutes and hoppers.

ASK
How do you think noise can be reduced along the pathway?

Expected answers:
¢ don't let the sound get from the machine to the worker

¢ put up some partitions

SHOW OVERHEAD .- List of control of noise along the pathway

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 3


N

v

SN

v

~

~

Vv

N

Vv

SAY

There are several ways to reduce noise along the path. They include:
¢ Increasing the distance between the source and the receiver

¢ Enclosing the noise source

¢ Interrupting the path or reduce reverberation

SHOW OVERHEAD - Example of enclosing the noise source [or show your own]

SAY
An enclosure around a machine might look like this. The enclosure will reduce the
amount of noise that can radiate from the source.

SHOW OVERHEAD - Example of shields and absorbing baffles [or show your own]

SAY

This overhead slide shows how a partial enclosure can be used to reduce noise. In this
example, high frequency noise is traveling directly form the high-speed riveting machine
to the worker’s ears. The solution was to partially enclose the riveting machine. The
hood is coated on the inside with sound-absorbing material. The upper portion of the
opening is covered with safety glass. As sound starts towards the ears, the glass reflects it
against the sound-absorbing walls, which reduces the sound level at the operator.

ASK
Do you have any ideas how to reduce noise at the worker?

SHOW OVERHEAD - List of noise controls at the worker

SAY

Controlling noise at the worker can be done by:

¢ enclosing the worker

¢ changing the work schedule or operations to reduce workers’ noise exposure such as
conducting a noisy operation over a period of a week, rather than one day

¢ transferring workers from noisy jobs to quieter jobs, but not at the expense of exposing
more workers to hazardous noise levels

* providing quiet areas where workers can gain relief from workplace noise

SHOW OVERHEAD - Example of enclosing the worker

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 4



EEE, _

v SAY
You can reduce the workers’ noise exposure by building an enclosure around the worker,
such as a control booth. Although the noise levels from the machine have not changed,
soundproof booths will prevent the noise from reaching the worker. All outlets must be
sealed to prevent noise from entering the enclosure.

% ASK
What is the least effective way of reducing noise exposure?

v SAY
Hearing protection devices should be used only as a last resort. As you'll soon learn,
proper selection, use and care of HPDs is not simple. It also takes a lot of work on your
part to make sure you’re wearing your HPDs properly and consistently. It’s much easier
if we make sure that there isn’t a noise problem to begin with.

Keep in mind, our policy here is to first choose engineering and administrative controls
that will reduce or eliminate noise -- such as buying quieter machines or changing
processes -- rather than those that simply reduce the workers’ time spent in noisy areas.

> SHOW OVERHEAD -_ Engineering and administrative controls implemented
or planned

v SAY
As you saw on the hazard map we showed you earlier, the level of noise you are exposed
to in [describe the work area or department] is [state levels of noise measured, area and
personal noise measurements].

That is why we have planned and implemented [or are in the process of planning and
implementing] engineering and administrative controls in your area. Listed on the
overhead are some of the engineering and administrative controls we have used [or plan
to use].

v ASK

Now that we know a little more about engineering controls, does anyone have any
suggestions for controlling noise in our facility?

& LIST (on a blank overhead slide or on a flipchart) what participants say.
v SAY

We will bring your ideas to the attention of [ name of person in charge of this area] and
will get back to you as soon as possible. [if possible, specify the state date].

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 5



= SUGGESTED ACTIVITIES

¢ Break participants into small groups and have them make a noise hazard map based on
their own experience. The noise hazards could be related to potential for hearing loss,
safety concerns, or stress. Participants then compare their noise map to the company
noise map and discuss any discrepancies.

+ Ask participants for suggestions on noisy areas to target and about ways to solve
problems that still exist.

¢ Participants create hazard maps of their off-the-job exposures and discuss possible
controls.

¢ Participants practice applying noise control methods and using sound level meters.
Participants are given noise generating devices (alarm clocks, buzzers or bells) along
with materials to control noise (boxes, foam, bubble wrap). Participants are asked to
take noise measurements of the devices before and after implementing engineering
controls.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM REDUCING NOISE - 6



Noise Survey
Results

[area #1 = xxx]
[area #2 = xxx]
[area #3 = xxx]

TWA for [job classification A = xx]
TWA for [job classification A = xx]
TWA for [job classification A = xx]

Noise Control 1



Noise Controls

¢ Engineering Controls - any
equipment modification, replacement
or physical change at the noise source
or along the path that reduces the
noise level at the worker’s ear

Administrative Controls - any
change in work assignment, production
schedules or policy decisions that
reduce noise exposure

Noise Control 2



Controlling Noise

¢ Source

¢ Path

« Receiver

Noise Control 3



Noise Controls:
Source

¢ Replace or modify
¢ equipment
* process
¢ materials

¢ Reduce vibration

¢ Schedule regular maintenance
and repair

¢ Establish “buy quiet” policy

Noise Control 4



Noise Controls:
Source

Aflat strip of metal
can be bent noisily
with a hammer

Noise Control 5



Noise Controls:
Source

room A room B

no vibration
isolation

noise from
building
floor
vibration

room A room B

machine
vibration
isolated

the area of
disturbance
vibration
isolated

Noise Control

6



Noise Controls:

foam material

rubber-plastic

horizontal
wire coils

mineral wool cellular << dense
material, rubber-plastic
rubber-plastic

softer springs <—e—-» stiffer springs

spiral spring, short thick leaf spring plate spring
long thin wire wire

Noise Control

7



Noise Controls:
Path

¢ Increase distance between
source and receiver

¢ Enclosure of noise source

¢ Interrupt the path/reduce
reverberation

Noise Control 8



Noise Controls:
Path

sound-absorbing
enclosure

sound absorbant
~ with perforated

| : cover layer
|

|

|

high-pressure line
(passage through
wall sealed with
a rubber collar)

Enclosure of a hydraulic motors release both sound
system requires muffled ven- and heat, as do the pump
tilation openings. Electric and the oil tank.

Noise Control



Noise Controls:

riveting hammer

safety glass

RAW LATHE

hood with sound-
absorbing material
on the inside

Noise Control 10



Noise Control:
Worker

Enclose worker
Change the work schedule
Change operations

Transfer workers
¢ do not expose more workers

Provide quiet areas for breaks
and meals

Noise Control 11


Noise Control:

ei

mineral wool
plasterboard \

vibration
isolated

Noise Control 12



Our Plans for
Reducing Noise

¢ What we have implemented

8 OOO]
° [Xxx]
° [Xxx]
* [xxx]

* What we are planning

© [xxx]
° [xxx]
* [xxx]
* [xxx]

Noise Control 13




SELECTION AND USE OF HEARING PROTECTION DEVICES

Teaching Objectives

¢ — explain the benefit of wearing hearing protection devices

* review the company method for selecting hearing protection devices

* discuss the proper use and care of hearing protection devices and common problems
associated with their use

Learning Objectives

Participants will be able to:

e describe the purpose of hearing protectors

¢ _ list the choice of hearing protection devices (HPDs) available to them

* describe the advantages and disadvantages of each type of HPD

* — explain the method used in selecting their department’s choices of HPDs
« demonstrate the proper use and care of their hearing protectors

ASK:
When do think you should wear hearing protection?

LIST (on a blank overhead slide or on a flipchart) what participants say.

Expected answers:
¢ when I run a noisy machine
¢ at work

¢ — incertain areas of work where noise is a problem

SAY

« Any time noise levels are at or above 85 dBA, you are at risk for hearing loss. The
more time you are exposed to high noise levels, the greater your chance of developing
permanent hearing loss. Simply put, whenever you have to shout to be heard you are
most likely being exposed to 85 dBA. Because the effects of noise accumulate, you
need to reduce your exposure to high levels of noise both on and off the job.

¢ — Ideally, the best way to keep you from being exposed to noise is through the use of
engineering controls. For example, we’ve been able to reduce the noise [add where
and which type of engineering control was used]. Because engineering and
administrative controls have not reduced the levels below 85 dBA in your area, you
need to wear hearing protection devices. Remember, to be adequately protected, you
must wear your HPDs properly and consistently.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEARING PROTECTION - |


S—0RoR0R0eo0o#0@$@M09@$@S${qas—=—pmOmwsqmeavwqysposoasg— 8080800 eee

Based on the noise levels we’ve measured throughout the facility, you’ll need to wear
hearing protection [state where or when hearing protection is required to be worn and
if wearing HPDs is a condition of employment]. [ name ] is in charge of this part of
the hearing protection component of our hearing conservation program.

2? ASK
What do you think keeps people from wearing hearing protection devices?

LIST (on a blank overhead slide or on a flipchart) what participants say, then add ideas that
participants do not volunteer.

Expected answers:

you can’t hear people speaking

I can’t hear my machine

HAPDs are really uncomfortable

I'm used to the noise, I don’t need to wear protection
they're difficult to use

it’s too much of a hassle to go get them

/ jSAY
As you can see, selecting, using and caring for hearing protectors is not so simple. In this
training, we will tell you how our facility’s hearing protection program has addressed the issues
that you have just raised. Let’s start by talking about hearing protection devices in more detail.

¥ SAY

Hearing protectors come in a variety of styles and models. Let’s go over the main types
of hearing protectors that are available. [Demonstrate each type you talk about.]

The three main types of hearing protectors you can choose from are:
-- earplugs

-- ear canal caps (semi-inserts)

-- earmuffs

[OPTIONAL: There are also more specialized HPDs available, such as custom molded
ear plugs, electronic-based HPDs and noise cancellation HPDs. Electronic HPDs
consist of earmuffs with electronics built in to take either outside sounds or radio
communication and electronically limit the level on the inside of the muff cup to a safe
value. Noise cancellation HPDs use sound sensors, amplifiers and speakers to generate
“anti-noise” or cancellation wave patterns to reduce the noise inside the earcup.]

All hearing protection devices reduce the amount of noise reaching the ear. For each
type of device, there are a lot of options. HPDs differ in design, the size, shape and
material used, and how much they can reduce noise. HPDs also vary in terms of how
much they reduce noise at specific frequencies.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEARING PROTECTION - 2


SS

2 SHOW OVERHEAD - Advantages and disadvantages of different types of HPDs

v* | SAY.

To review the general characteristics, advantages and disadvantage of the various HPDs
available, let’s review the next overhead slide.

Earplugs

more protection
at 125 Hz than
muffs

varied NRRs

Semi-aural varied NRRs

caps

more protection at
500 - 8000 Hz
than earplugs
varied NRRs

¥Y SAY

inexpensive

readily available

come in a variety of styles
some can be cleaned and
reused

can be custom molded

(is more expensive)
linear attenuation models
are available

can be easy to insert
various styles

clean fingers are not
required

many repeat usages
good for people going in
and out of noisy areas

can be dedicated to work
area

last much longer

easy to see on workers
can be fitted on hard hat
can be radio-equipped
linear attenuation models
are available

require clean fingers
proper insertion takes time
and training

not always properly
inserted

additional cost
typically lower NRRs

higher cost

cannot be used with
glasses (breaks the seal)
not usually comfortable in
hot, humid environments

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM

In general, earplugs reduce noise more than earmuffs at the lowest frequencies (125 hertz),
whereas in the 500-8000 Hz range, ear muffs reduce noise more. HPDs that reduce noise
equally in all the frequency bands are called “linear,” “musician’s earplugs,” or “flat
attenuation” devices. Earmuffs and earplugs models that provide linear reduction are
available. Linear HPDs are useful for workers with preexisting hearing loss. Remember,
workers with hearing loss have problems hearing the speech frequencies. Communication
is more difficult when wearing non-linear HPDs, because these HPDs reduce sound levels
in the speech frequencies to below what workers with hearing loss can hear.

HEARING PROTECTION - 3


2 SHOW OVERHEAD - Noise survey results for group participants

¥ SAY
¢ To determine what type of hearing protection device to use in the various areas of the
facility, the noise survey results were reviewed.

NOTE TO TRAINER: If this section of the training is done immediately following the
Reducing Noise Hazards section, do not repeat the review of the noise survey results.

If this section of the training is done after significant time has elapsed since participants
have been through the Reducing Noise Hazards section, say “The results of the noise
survey for this [department, job classification] are [review results].”

e¢ Based on this information, we made sure the initial choices of HPDs had Noise
Reduction Ratings (NRR) protective enough for your work environment. The NRR is
the amount of protection the manufacturer says their hearing protectors can provide.

> SHOW OVERHEAD - calculation using laboratory-based NRR vs. real-world NRR

NOTE TO TRAINER: The following is an example of how to calculate the real-world
NRR using an E-A-R ultrafit earplug.

¥ SAY
¢ For example, [the E-A-R ultrafit] has an NRR of 21 dB. This means that if you wear
this type of HPD in a work area where the noise levels were measured at 98 dBA, your
exposure would be reduced to 77 dBA. This sounds great, but this is the ideal situation.
In the real world, HPD reduction (also called attenuation) is a lot less.

* To make sure that our HPD choices would really protect you enough, we used the
OSHA method for estimating real world attenuation. In this method, 7 is subtracted
from the NRR, the remainder is then divided by 2 to get the real-world attenuation.
Using the example of the E-A-R ultrafit, the real-world attenuation would be 7dB
(21 -7/ 2), not 21 dB. In other words, if you are exposed to 98 dBA and wear this
hearing protector, your actual exposure will be 91 dBA not 77 dBA. Therefore, the
actual exposure is above both the OSHA permissible exposure limit and the exposure
limit recommended by NIOSH.

NOTE TO TRAINER: You may want to use the NIOSH recommended method for

estimating real-world attenuation. This is summarized in Chapter 6 of the NJOSH Criteria
for a Recommended Standard: Occupational Noise Exposure, 1998.

OOO. Oooo———
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEARING PROTECTION - 4


=...

¥ SAY
¢ To narrow down the choices we:

-- reviewed the various areas in our facility to make sure problems would not come up
with the use of any particular type of HPD (for example, communication, heat,
humidity or dust in the environment]

-- based the final selection on comfort, convenience, ease of fit
--- we met with several co-workers and asked for their feedback on what HPDs

they found were comfortable, easy to fit & convenient to use
¢ The specific types and models we offer are:

-- three earplugs [specify which]

-- two earmuffs [specify which]

-- one semi-aural [specify which]

* [state any department or job specific recommendations or restrictions]

> SHOW OVERHEAD - Fit, use and care of HPDs

¥ SAY
« When it comes to the fit, use and care of HPDs

-- your initial HPD fitting and training will be done by [specify name of a trained
person]

-- your HPD fit will be rechecked by the audiometric technician at the time of each
annual audiogram

-- remember to fit and adjust your HPDs before and during the work shift.

-- review the manufacturer’s instruction for use and care of your HPDs [specify]

-- for replacement HPDs you’ll need to see [specify]

¥ SAY
* As we found out in the health effects section of this training, you need to wear hearing
protection any time you are exposed to high levels of noise -- including exposures at
home.

¢ Ifyou need to use hearing protection off-the-job see [name person]. He/she will help
you with the appropriate type of HPD.

2? ASK
Are there any questions, comments or suggestions?

ts ADDITIONAL SUGGESTED ACTIVITIES
¢ Break into teams of two. Have workers demonstrate to each other how to put on
hearing protectors and check for fit.
¢ Break into small groups. Have each group discuss what keeps workers from wearing
HPDs and identify solutions. Then have the small groups report their solutions to the
entire group.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM HEARING PROTECTION - 5




Types of HPDs

- Earplugs

- Semi-aural (Ear Canal Caps)

- Earmuffs



Earplugs

¢ require clean
fingers

* more protection inexpensive
at 125 Hz than

muffs

e readily available

* proper insertion
takes time and
training

* come in a variety
of styles

e linear

e varied NRRs

* some can be
cleaned and
reused

can be custom
molded (more
expensive)



Semi-aural Caps

¢ varied NRRs * can be easy to ¢ not always
insert properly inserted

various styles ¢ additional cost

clean fingers are |* typically lower
not required NRRs

many repeat
usages

good for people
going in and out
of noisy areas



Earmuffs

* more protection
at 500 - 8000 Hz
than earplugs

¢ NRRs vary
widely

oe ee

can be dedicate
to area

last much longer

easy to see on
workers

can be fitted on
hard hat

can be radio-
equipped

e higher cost

¢ cannot be used
with glasses
(breaks the seal)

¢ not usually
comfortable in
hot, humid
environments

HPDs

4



Noise Survey
Results

[area #1 = xxx]
[area #2 = xxx]
[area #3 = xxx]

| - TWA for [job classification A = xx]
| - TWA for [job classification A = xx]
| - TWA for [job classification A = xx]



Laboratory vs.
Real-World NRR

TWA 98 dBA
measured using

a dosimeter

NRR of E-A-R | 21 dB
Ultra fit

Formula

= worker’s TWA - NRR

Laboratory 98 dBA - 21
estimated
worker’s TWA
wearing E-A-R
Ultra fit

98 dBA

measured using
a dosimeter

NRR of E-A-R | 21 dB
Ultra fit

Formula
= worker’s TWA - (NRR-7)/2

98 dBA- (21-7/2)

Real-world
estimated

worker’s TWA
wearing E-A-R
Ultra fit

98 dBA - (14/2)
98 dBA - 7

= 91 dBA

HPDs 6


Fit, Use & Care Of
HPDs

Initial fitting & training is done by
[name]

Fit is rechecked at annual audiogram

Fit & adjust your HPDs before &
during work shift

Review manufacturer’s instructions

See [name] for replacements & off-the-
job needs

HPDs 7





THE ROLE OF AUDIOGRAMS IN HEARING CONSERVATION

S Teaching Objectives:

. To explain the role of audiometric testing in preventing hearing loss
. To describe audiometric testing procedures
. To discuss the interpretation and implications of test results

S Learning Objectives:
Participants will be able to:

. state the purpose of hearing (audiometric) testing
. explain when audiograms will be give
: describe hearing test procedures
° describe what hearing loss looks like on an audiogram (normal, noise-induced, aging)
° describe follow up activities that should take place when hearing loss occurs
5 ASK
Why do you think audiometric testing is important?
# LIST participants’ answers (without criticism), then indicate which you will be covering in
this section.
Expected answers:
¢ so we'll know if we can hear okay
¢ checking our hearing every year can tell us if we're loosing our hearing
¢ OSHA says we have to get it
v SAY
¢ Hearing tests are the only way to tell for sure that a hearing conservation program is
working. Because occupational hearing loss occurs gradually, we often do not notice a
change in hearing ability until a relatively large loss has occurred. Comparing annual
hearing tests tells us early on if any workers are developing mild hearing losses. We can
then do something to prevent further losses. For example, we can evaluate and improve
engineering controls, refit hearing protectors, find out if off-the-job activities are the
cause of the hearing loss, or retrain workers, so that no one suffers additional hearing
loss.
7 ASK

When are audiograms given?

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM AUDIOGRAMS - 1



Se
> SHOW OVERHEAD - When audiometric testing is done

v SAY
* All workers will be given baseline audiograms as part of their pre-employment medical
examination. We give hearing tests to all employees for two reasons: One reason is that
it is a good idea for everyone to monitor their hearing. The second reason is to compare
the audiograms of the workers who work in noisy areas to those that work in quieter
areas. If our hearing conservation program is effective, then the audiograms should be
the same -- no hearing loss in either group.

* Annual audiograms will be given to workers who are exposed to 85 dBA or more for an
8-hour shift, for as long as they work in the noisy environment. This group of workers
will be individually fitted with hearing protection devices by [name of person responsible
for fitting HPDs]. If workers are assigned to areas where noise levels are less than 85
dBA, they will be given follow-up audiograms every 2-3 years.

¢ Ifan annual audiogram shows hearing loss compared to the baseline, a retest is done
immediately. If the results are the same then the confirmation audiogram is scheduled
within 30 days.

* Exit audiograms will be given to workers when they leave a noisy job or leave the
company.

[OPTIONAL: Workers assigned to areas where the noise levels are 100 dBA or more will get
their hearing tested twice a year just to make sure their hearing protection is adequate.
Research has shown that the most susceptible 10% of a population exposed to daily average
noise levels of 100 dBA with inadequate hearing protection could develop significant hearing
loss well before the end of one year.]

? ASK
What is the actual hearing test procedure?

NOTE TO TRAINER: If participants have already had a baseline audiogram at the time of
training, change the language of this section to the past tense. For example, say “As you
remember, the audiometeric technician first took your noise exposure history, etc.]

7.» SAY.
¢ The testing procedure is the same any time an audiogram is given. At the time of the
testing, an audiometric technician will:
-- get your noise exposure history information
-- check your HPD for its fit and condition
-- instruct you on how to take the test
-- explain your results to you

ooooaqleleleeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM AUDIOGRAMS - 2



—eRqRleoooooooooeeweweee_

¢ The technician will seat you in an audiometric test booth and fit you with a set of
earphones. Your hearing is tested with an audiometer which sends audio signals in different
frequencies through the earphones. Your hearing will be tested in seven different
frequencies: 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hertz.

> SHOW OVERHEAD - Sample audiogram
* You'll respond when you can first hear the sound generated by the audiometer. The softest
sound you can hear at a specific frequency is called the hearing threshold for that
frequency. The hearing threshold for each frequency that is tested is plotted on an
audiogram that looks like this.

¢ The graph is similar to a piano keyboard with low to high frequencies (or pitches) going
from left to right. The intensities (or loudness) of the sounds are arranged from the top of
the graph (soft sounds) to the bottom (loud sounds). The intensities are expressed in terms
of sound pressure levels, called decibels (dB) or decibels hearing threshold level (dB HL).
Responses are recorded using a "O's for the right ear and "X”s for the left ear.

* Before you’re given the baseline audiogram, you should not be exposed to noise levels at or
above 85 dBA for 12 hours. Wearing your hearing protectors does not substitute for the
quiet period. The reason we want you to have 12 hours of quiet is to make sure you’re
being tested at your best. These conditions hold true for the confirmation and exit
audiograms, but are different for the annual hearing test.

¢ The annual hearing test is given while you’ve already been at work because comparing
results with your baseline audiogram will show any early signs of hearing loss due to
excessive exposure. In the early stages of work-related hearing loss, noise exposures cause
temporary shifts in hearing. These shifts can become permanent, if repeated on a regular
basis. By testing toward the end of the workday, rather than before the work starts, these
temporary shifts can be noted and we can take steps to prevent them from progressing any
further.

> SHOW OVERHEAD - Normal audiogram

? ASK
What does a normal audiogram look like?

v SAY
If you have normal hearing, your responses to the audiometer at the test frequencies will fall
between 0 dB and 25 dB. [Use pointer to show where the line is falling between 0 and 25 db]

> SHOW OVERHEAD - Noise induced hearing loss audiogram

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM AUDIOGRAMS - 3



¥ SAY
* Ifyou have a hearing loss it might show up like this on the audiogram.

* _ This type of hearing loss is called noised-induced hearing loss. This type of impairment
frequently shows a notch in the audiogram at 4,000 Hz with better hearing at 8,000 Hz as
shown. As described earlier, dB on an audiogram refers to loudness levels. The more the
volume on the audiometer has to be turned up for the worker to hear, the higher the
decibel level reading on the audiogram. For the notch at 4000 Hz the volume has to be
turned up to 40 dB for the worker to hear sounds at this frequency.

* When reading an audiogram, keep in mind that a value of zero dB is a reference level.
Zero represents the softest sound that an average young adult (with good hearing) can
hear at that test frequency. In fact some people with exceptionally good hearing will have
audiograms showing responses below zero dB. In this audiogram, the worker has good
hearing particularly in the test frequencies of 125, 250 and 2000 Hz.

= SHOW OVERHEAD - Age-related hearing loss audiogram

SAY
* The effects of aging can also be seen on an audiogram. Typically, losses are seen at the
higher frequencies between 6000 and 8000 Hz.

? ASK
What happens if a hearing loss is seen on your audiogram?

v SAY
¢ The technician compares your annual audiogram to your baseline looking for a

Significant Threshold Shift. A Significant Threshold Shift is a 15 dB change in any of
the test frequencies (500 to 8,000 Hz) in either ear. If the technician sees the shift, a
retest will be given. If the retest gives the same results, then you’ll be scheduled for a
confirmation audiogram to be taken within 30 days. Because the OSHA standard
requires it, we will also test your hearing at 2000, 3000 and 4000 to see whether you have
a standard threshold shift. This is defined by OSHA as an average of 10 dB increase in
hearing threshold at these three frequencies, in either ear.

¢ The confirmation audiogram, like the baseline, should be conducted after a minimum of
12 hours of quiet, without the use of hearing protectors. If the confirmation audiogram
indicates a persistent or permanent threshold shift, you'll be notified in writing and
referred to [name person who will be the professional reviewer] for a review of your
audiogram to find out the cause of your hearing loss. If the cause is not noise, then you’ll
be referred your own physician for evaluation and treatment.

HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM AUDIOGRAMS - 4


~~

~

ASK
What do you think should be done if someone’s audiogram shows hearing loss?

Expected answers:

¢ — give them better hearing protection

¢ train them better

¢ find out if they're doing something noisy off-the-job

¥ SAY

These are all good ideas. Let’s review what we will do at our facility if someone has hearing

loss. We will:

-- check the fit of the hearing protection devices (HPD). It may be necessary to change the
type of HPD for better protection.

-- find out if you’re being exposed to noise off-the-job

-- give you more training so you can understand why and how to protect your hearing

-- check noise levels in your work area. Maybe it’s noisier than the initial measurements
indicated

-- move you to a less noisy job, if necessary

ASK

* Does anyone have a question?

* Have you had any problems with any part of the hearing test process?

* Do you have any recommendations for improvements in this part of the hearing
conservation program?

ADDITIONAL SUGGESTED ACTIVITIES

¢ Audiogram game. Divide participants into 5 teams. Each team receives one of 5
different audiograms, each matched with one of two different baseline audiograms. The
trainer draws a ticket with the name of a type of hearing loss. The team to identify that it
has the audiogram that shows the selected type of hearing loss and why it is an example
of the type wins. Then the next type ticket is drawn until all types have been reviewed.
Everybody’s a winner. (As prizes, you can give out miniature candy bars or safety-
related trinkets.)

¢ Guest lecturer. Invite an audiometric technician or audiologist give a talk about case
studies.

¢ Play a tape of hearing and show what the person’s audiogram would look like.

T_T
HUNTER COLLEGE COEH NOISE HAZARDS CURRICULUM AUDIOGRAMS - 5





Audiometric
Testing.

Pre-employment baseline
Annual
Follow-up

Exit

Audiometric 1



E
6
te
5)
=
5
5
= |

(4H gp) [eAe7 ployseiy, Buea}

Audiometric



Audiogram of
Normal Hearing

Hearing Thresholds of a Person with
Hearing in the Normal Range
S

De FER Re oF te Pee AS

| | ttl
eS Ss ee oe
requency (Hertz

Hearing Threshold Level (dB HL)
3

Audiometric

3


Audiogram of
Noise-Induced
_Hearing Loss

Hearing Thresholds of a Person with
Noise-induced Hearing Loss

§
so

=
=x
mo
KS)
=
os
>
®
=a
3
c=
n
E
a
c
c
o
a
=x

Frequency (Hertz)

Audiometric 4



Audiogram of
Age-Related
Hearing Loss

Hearing Thresholds of a Person with
Hearing Loss due to Aging
S € §

6
v v § s v

$009

bd
o

Hearing Threshold Level (dB HL)
a8 86s

sees

Frequency (Hertz)

Audiometric 5