1
March 2011
© 2011 3M. All Rights Reserved
By: Elliott H. Berger &
Laurie L. Wells
Elliott H. Berger, M.S., is a Division
Scientist for 3M’s Occupational
Health & Environmental Safety.
Laurie L. Wells, Au.D., is Manager
of Audiology for Associates in
Acoustics, Inc.
Tinnitus and Hearing Protection:
Fiction and Fact
I pulled the trigger. My ears have never been the same since. All I could hear
was ringing, constant, infuriating ringing, all the time, ringing, ringing, ringing.
No matter what I did, where I went, who I was with, ringing. That one brief
instance changed me forever…..
One brief instance, one unprotected gun shot, airbag deployment, or firecracker
explosion can cause hearing loss, tinnitus, or both, which for some will become a
permanent and devastating life-changing experience.
Sure, I have ringing in my ears all the time. It seems like I’ve had it all my life. I
hardly notice it. It does seem to get louder after I have been around a lot of
background noise. Once in awhile it keeps me awake at night, but I don’t really
think about it much.
A much more common story - adapting to life with tinnitus while challenging for some
is merely a nuisance for others. Each person’s tinnitus and circumstances are
unique, but what is true for all those with tinnitus is that having good hearing
protection options can make life in our noisy world more comfortable. And for those
who don’t have tinnitus, proper use of hearing protection may be the answer to
remaining “tinnitus free” for life.
Misinformation and misconceptions about tinnitus and hearing protection are plentiful,
so an overview of fiction and fact is a good place to start our discussion. While not an
exhaustive list, Table 1 summarizes some common issues that are further explained
below. First, a definition: tinnitus is a generic word for the perception of sound that is
not associated with actual physical acoustic energy. It seems to come from inside the
head and lasts for at least a few minutes at a time. It is commonly described as
March 2011
© 2011 3M. All Rights Reserved
ringing, chirping, roaring, buzzing, whooshing, hissing, frying bacon, peeping or
something similar.
No one understands my tinnitus…
Actually, tinnitus is more common than you might think. Estimates suggest that from 6
– 17% of the population, or perhaps as many as 50 million Americans, have tinnitus.
A much smaller percentage (about 3 - 7% of the general population) is bothered by
tinnitus enough to seek medical attention. An even smaller percentage of people
consider their tinnitus so debilitating that it keeps them from leading a “normal” life.
Chances are good that if you start asking your family members and friends, you will
discover someone who has tinnitus and who can relate to your experience. People
who have hearing loss, particularly noise-induced hearing loss, and the elderly
population, are more likely to have tinnitus. A notable national organization dedicated
to helping those with tinnitus is the American Tinnitus Association (ATA). Visit
www.ata.org
for current resources and to locate a local support network.
Disease or symptom?
Tinnitus is an indicator of abnormal function, but it is not a disease in and of itself. In
this way it is similar to headache, elevated blood pressure, or dizziness, each of
which signals something is wrong with the body, but none is a disease. Although
tinnitus has been studied extensively, the cause and mechanics of tinnitus are not
well understood. Because the ear detects sound and the brain processes it, it is
generally accepted that both the hearing mechanism and the brain are involved with
the origination of tinnitus. Some believe tinnitus is extra activity of the auditory
neurons – in the nerve pathways of hearing. Tinnitus is often associated with certain
medications, but interestingly having tinnitus is not more common among people who
consume caffeine, nicotine, or alcohol. Things like the condition of one’s health, noise
exposure, and the degree of hearing loss are all correlated with the presence and the
severity of tinnitus.
Tinnitus and hearing loss
Hearing loss and tinnitus often occur together, but tinnitus is not a cause of hearing
loss. However, tinnitus may be an early indicator of damage to the auditory system,
showing up before a loss of hearing is obvious. Certain ear diseases or conditions
are more likely to exhibit accompanying tinnitus than others. People who have a
history of loud noise exposure, Meniere’s disease, otosclerosis, age-related hearing
loss, sudden hearing loss or a benign growth on the hearing or balance nerve are at
high risk of also having tinnitus. It is advisable for those with tinnitus and/or hearing
loss to see a physician and audiologist to diagnose the condition and to explain
treatment and management options. For those with a sudden onset of tinnitus or
March 2011
© 2011 3M. All Rights Reserved
hearing loss, the sooner you receive medical intervention the better the chances are
for recovery.
Living with tinnitus
Most people learn to live with tinnitus without any treatment. However, for a small
percentage, tinnitus is such a chronic and unpleasant experience that seeking relief is
essential. Hearing the message from a healthcare provider, “there is nothing you can
do about it, just learn to live with it,” can be devastating. True, there is no cure today
for tinnitus, no magic pills, surgery, or diet to silence the internal, unwanted sounds,
but there is hope for treatment and/or management of the condition. Initially, an
evaluation should be conducted to identify the underlying condition causing the
tinnitus. If this condition can be medically or surgically treated, then the tinnitus may
be substantially improved or eliminated. In circumstances where there is no medical
treatment available, as in the case of tinnitus arising from permanent noise-induced
hearing loss, there are still options available to help manage the tinnitus. The two
basic approaches are: 1) lessen the awareness of the tinnitus and 2) relieve the
stress and negative emotional reactions that it triggers. Some tinnitus therapies utilize
both strategies by incorporating counseling, education and the use of competing
sound intended to distract one from constantly hearing the tinnitus. The overarching
goal is to return to the pre-tinnitus quality of life.
Unfortunately, many studies have concluded there isn’t one best treatment option. It
isn’t uncommon for people who are desperate to find help to fall prey to
advertisements and false promises. Consulting a professional organization of
audiologists or physicians with specialty training in tinnitus treatment is
recommended. See Table 2 for more information.
Tinnitus and hearing protection
Exposure to loud noise is one of the most common causes of hearing loss and
chronic tinnitus. Generally speaking, the louder the noise and the longer the time of
exposure, the greater the risk for hearing damage (noise-induced hearing loss) and its
common side effect: tinnitus. Proper use of hearing protection when you are exposed
to loud noise is essential – especially if there is some hearing loss and tinnitus
already present. You should use hearing protection whenever it is so loud you must
shout in order for the person next to you to hear you clearly (roughly 85 dBA), and
especially in the presence of high-level impulse noise such as that produced by
gunfire or explosions. Because loud sound can aggravate existing tinnitus, it may be
advisable to use hearing protection at lower noise levels, for example when you have
to talk loudly for the person at arms length from you to understand (roughly 80 dBA).
March 2011
© 2011 3M. All Rights Reserved
Which hearing protector?
Not all hearing protectors are created equal. With many options of styles, colors, and
materials, selection can be a bit overwhelming. Basic types of hearing protectors are
“roll-down” foam earplugs, push-to-fit foam earplugs, flanged or premolded earplugs,
custom-made earplugs, “banded” earplugs and earmuffs.
•
Traditional foam earplugs require some skill to insert properly since they must be
rolled into a small cylinder before they are inserted into your ears. However, they
are forgiving and, even when not inserted optimally, can provide a reasonable
noise-blocking seal. If worn correctly, traditional foam earplugs tend to be the
most comfortable and effective style of earplug, providing noise reduction that
rivals high-attenuation earmuffs.
•
Push-to-fit foam earplugs are easier to use than traditional foam since they don’t
need to be rolled before inserting them into your ears, yet they can provide similar
levels of comfort and protection.
•
Premolded earplugs are made of an elastic material that can be washed and
reused for a longer time than foam earplugs. Although they can seal well, they
tend to be somewhat less comfortable and less protective than foam earplugs.
They can’t usually be inserted as deeply as foam earplugs without discomfort,
and they require repositioning to maintain the acoustic seal in the earcanal.
•
Custom-made earplugs are much more expensive than non-custom types and,
contrary to intuition, are usually not the most protective. Even so, for some
applications and individuals, custom-made earplugs may be a great choice for
comfort, ease of use, and adaptability.
•
Banded (also called concha seated and semi-aural) earplugs are primarily
intended for intermitted-use applications since they easily store around the neck
while not in use.
•
Earmuffs are easy to use, quick to put on and take off for short-term exposures
and provide warmth, which is welcome in cold environments. Also, earmuffs are
an ideal solution for people who object to putting something inside their ears.
You may have to experiment among different types of earplugs and earmuffs to find
what is best for you. The “right choice” is the one which blocks sound, is convenient
to carry with you, and is comfortable enough to wear consistently. It isn’t necessary
to buy the most expensive product because effective protection can be achieved with
simple, less expensive options. To ensure that you are choosing devices designed to
reduce your noise exposure, look for the Noise Reduction Rating (NRR) on the
product packaging. Products with an NRR have been developed, studied, and
objectively measured using scientifically accepted laboratory procedures. These
products are preferable to make-shift devices like cotton balls or wadded-up paper
that allows hazardous sound to penetrate into the ear. However, don’t get hung up on
the actual NRR; small differences between NRRs of 4 or 5 decibels (dB) won’t make
a significant difference in the overall performance.
March 2011
© 2011 3M. All Rights Reserved
Most important for good performance is how well you fit the product to your ear; the
better the fit, the greater the protection. A poor fit means less protection due to air
leaks, or worse, no protection if the earplugs stay in your pocket instead of your ear.
As a rough guide, you can presume that devices with NRRs of 29 dB and greater are
capable of providing the highest possible protection. Those with NRRs of 16 dB and
lower are likely to provide modest protection. The lower values of protection are often
quite sufficient (and even preferred) for common recreational exposures other than
shooting or the loudest of rock concerts.
Learning to fit your ears with hearing protectors is made easier with demonstrations.
Visit
www.e-a-r.com/hearingconservation/video_main.cfm
for short instructional videos on
fitting earplugs. An in-depth brochure called Tips and Tools for Fitting and Using
E•A•R
™
Foam Earplugs, applicable to all brands and types of roll-down foam earplugs
is available at
www.e-a-r.com/hearingconservation/booklet_main.cfm
. Other types of
hearing protectors also require correct use. See EARLog 19 for numerous
suggestions on a broad range of products
www.e-a-r.com/hearingconservation/earlog_main.cfm
.
Hearing with hearing protection
Hearing protectors block the external sound from entering the ear but don’t totally
stop all sound from getting through. Conventional hearing protectors filter out more of
the high pitches than the low pitches, which alters the sound quality. Furthermore, the
sounds inside the head seem different to you when you are wearing hearing
protectors; your voice and body sounds become fuller, boomy, hollow-sounding, and
muffled. This is called the occlusion effect. To experience this, try sealing your
earcanals with your thumbs and read this sentence aloud while listening to your voice.
Fitting the hearing protectors more deeply in the earcanals will minimize the occlusion
effect and the sound will be more natural.
March 2011
© 2011 3M. All Rights Reserved
More is better?
Not always. People use hearing protection for many different reasons and in many
environments: to protect hearing from hazardous occupational noise, while shooting
firearms, to improve their ability to concentrate on reading in an airport, or perhaps to
sleep during the day when neighborhood children are playing outside. Some of these
situations require hearing protection to reduce noise to a safe level, but others simply
use hearing protection to block out unwanted or annoying sounds. Interestingly,
people with tinnitus often rely on background noise to interfere with the sound of the
tinnitus. Limiting the background noise with hearing protection may make the tinnitus
seem more noticeable. This is likely to be more of a problem in low-noise
environments or with hearing protectors that provide more noise reduction. When
noise is loud enough to require hearing protection for safety reasons (greater than 85
dBA), the hearing protection can block hazardous noise while still allowing enough
sound to pass to still provide distraction from the tinnitus. Remember, changes to the
awareness of the tinnitus due to the use of hearing protection are temporary; using
hearing protection appropriately will prevent long-term noise-induced damage and
potential worsening of the tinnitus.
The amount of noise reduction needed depends on both the purpose for using
hearing protection and the background noise level. To decide if “more is better” think
about the reason you are using hearing protection and choose a product that works
for that specific environment. Many noise exposures only require about 10 dB of
noise reduction for adequate protection from noise damage. So, unless you simply
prefer the extra quieting that maximum noise reduction will provide, you can choose a
product with lower noise reduction and not be troubled by being isolated from the
sounds around you.
An excellent choice for taking the edge off of annoying sounds while still allowing
easy communication is the ER-15 Musicians Earplugs™ (see
www.etymotic.com
).
Although more expensive, at over $100/pair, this custom molded earplug is
comfortable to wear and sounds more natural because it reduces all pitches of sound
equally and avoids the muffling effect so common with conventional products. An
alternative, much less expensive product (about $15/pair), is a “one-size-fits-most”
flanged earplug that can be purchased off the shelf – E•A•R™ Hi-Fi earplugs (also
called ER-20 earplugs). Like the custom ER-15, the Hi-Fi earplugs are intended for
adequate and not maximum protection and thus are ideal for music exposures and
many public entertainment events.
Another popular approach to controlling unwanted noise is active noise reduction
(ANR; sometimes also called noise cancellation). This method depends on
electronics to process the sound that travels through the hearing protector. The sound
March 2011
© 2011 3M. All Rights Reserved
is modified and reintroduced through a small earphone that partially cancels the
incoming sound. This technology works well for low-frequency sound below about
400 Hz, such as the loud rumbling engine noise inside aircraft or military vehicles. It
has many commercial and military applications. For consumers who want enhanced
listening experiences, ANR is most often used in earphones or earplugs that can be
coupled to listening devices. Such devices are useful for enjoying music or sound
tracks while reducing unwanted noise in an aircraft cabin or subway car. If a high
degree of noise protection is needed, less-expensive non-electronic insert earphones
(i.e., earplugs) that seal well in the earcanal can be used instead of an ANR device.
Life can be loud…
Make sure you are getting the protection you need. If immediately following a noise
exposure you experience increased or sudden onset of tinnitus, or if your hearing
seems muffled or fuzzy, the noise was too loud. Regular exposures like that will
probably lead to hearing loss and/or permanent or increased tinnitus. Since you can’t
always predict when you will be exposed to noise, keep your hearing protection
handy, just like you might carry a pair of sunglasses. Having appropriate hearing
protection options for different listening situations is also helpful. Earplugs are small,
lightweight, and easy to store in a pocket or travel bag. You can even bring an extra
pair or two for someone else who is caught unprepared. After all, the fact is replacing
earplugs is easy, but replacing hearing is still fiction.
March 2011
© 2011 3M. All Rights Reserved
Table 1 – Tinnitus: fiction and fact
FICTION FACT
No one can understand how bad my
tinnitus is.
Tinnitus is more common than you think.
Start talking to others and you are likely to
find someone close to you who has a
similar experience.
Tinnitus is a disease.
Tinnitus is a symptom.
Tinnitus causes hearing loss.
Tinnitus commonly accompanies hearing
loss, but is not the cause of hearing loss.
Nothing can be done about tinnitus. One
just has to learn to live with it.
There is no tinnitus cure, but something
can be done. Sometimes the underlying
condition causing the tinnitus can be
medically treated. Or, as is the case for
noise damage, there are a variety of
management approaches that can provide
tinnitus relief.
I already have tinnitus, so I don’t need to
protect my hearing.
Using hearing protection can prevent the
onset or aggravation of tinnitus and
hearing loss.
All hearing protection is the same.
There are many different types of hearing
protection, and the “best” one may be
different for each person.
The higher the number on the hearing
protection package, the better.
The degree of sound reduction varies,
depending on many things, including how
well the hearing protector fits the ear. The
number on the package is not the only
thing to consider when choosing the best
protector for you.
Using hearing protection will make my
tinnitus worse.
Tinnitus may temporarily be more
apparent while wearing hearing
protection, especially with hearing
protectors that provide higher noise
reduction and/or in lower ambient noise.
But hearing protectors may help prevent
the noise from permanently making the
tinnitus worse with time.
More noise reduction is always better.
The hearing protection choice depends on
the purpose for using it and the
background noise level.
March 2011
© 2011 3M. All Rights Reserved
Table 2 - Tinnitus and hearing protection resources
American Academy of
Audiology
www.howsyourhearing.org
American Speech-
Language-Hearing
Association
www.asha.org/public/hearing/Tinnitus-Management
American Tinnitus
Association
www.ata.org
American Academy of
Otolaryngology-Head and
Neck Surgery
www.entnet.org/HealthInformation/tinnitus.cfm
3M hearing conservation
and hearing protection
fitting information
www.e-a-r.com/hearingconservation
Etymotic Research, Inc.
(high fidelity earplugs)
www.etymotic.com/ephp/er20.aspx
National Institutes of
Health
www.nidcd.nih.gov/health/hearing/tinnitus
National Hearing
Conservation Association
www.hearingconservation.org
Oregon Hearing &
Science University
Tinnitus Clinic
www.ohsu.edu/xd/health/services/ent/services/tinnitus-
clinic/index.cfm
References
Dobie, R. A. (2004). “Overview: Suffering from Tinnitus.” in Tinnitus: Theory and
Management, editor James B. Snow, BC Decker Inc., Hamilton, London 1-8..
Hoffman, H. J. and Reed, G.W. (2004). “Epidemiology of Tinnitus, in Tinnitus: Theory
and Management, editor James B. Snow, BC Decker Inc., Hamilton, London, 16 – 41.
Jastreboff, P. J. and Jastreboff, M. M (2003). “Tinnitus and Hyperacusis,” in
Ballenger’s Otorhinolaryngology Head and Neck Surgery 16
th
Edition, editor James B.
Snow, BC Decker Inc., Hamilton, London 456 – 475.
March 2011
© 2011 3M. All Rights Reserved
About the Authors:
Elliott H. Berger, M.S., is a Division Scientist for 3M’s Occupational Health &
Environmental Safety Division. For over 30 years he has studied noise and hearing
conservation with an emphasis on hearing protection. Elliott chairs the ANSI working
group on hearing protectors, has been lead editor for two highly-regarded texts in
noise and hearing conservation, served on a National Academy of Science committee
evaluating hearing loss in the military, and has presented his research in numerous
text book chapters and over 60 published articles.
Laurie L. Wells, Au.D., is Manager of Audiology for Associates in Acoustics, Inc., a
professional consulting firm specializing in hearing loss prevention through
occupational audiology, noise measurement and noise control efforts. Laurie
oversees audiometric monitoring programs for companies and corporations across
the United States and is an active presenter and teacher on hearing loss prevention
topics. She currently represents the American Academy of Audiology on the Council
for Accreditation in Occupational Hearing Conservation and is past president of the
National Hearing Conservation Association.
Visit
http://www.3M.com/Hearing
to register for training, download files, or other
materials.
Become a fan at
http://www.Facebook.com/3MHearingProtection
3M Occupational Health & Environmental Safety Division
3M offers comprehensive product solutions providing respiratory protection, hearing
protection, fall protection, visibility and protective clothing, eyewear, head and face
protection, welding helmets, and other adjacent products and solutions such as
tactical safety equipment, detection and monitoring, compliance management and
spill management. Visit
www.3M.com/OccSafety
Dostları ilə paylaş: |