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As printed in Hearing Health, volume 19:2,
summer 2003
By Margie Littell Ulrich, CCC-A
When people purchase behind-the-ear (BTE) hearing
aids, they often give little thought to the marvel of
technology called an earmold that places amplified sound
in their ears. Others who choose an in-the-ear (ITE)
instrument may not realize the contribution of its shell,
thinking that all it does is house those circuits and
microphones, etc., that their hearing care professionals
talk about. In reality, though, selecting the correct
earpiece is more complicated than it first appears and
more important since it affects the sound quality of
the hearing aid.
Hearing aid dispensers do not have an easy decision
in choosing the most appropriate earmold or earpiece.
There are a variety of materials and dozens of different
styles or designs plus the range of colors and motifs
grows daily.
Of course, being stylish is not the primary concern.
First of all, earmolds should never hurt the ear. Unfortunately,
there is a very fine line between the earpiece being
tight enough to prevent sound leaking out of the ear
canal, causing the hearing aid to whistle or screech,
and being too tight, causing ear pain. With some people,
repeated ear impressions are required to get a proper
fit.
Even the materials used to make an impression can
make a difference in the final fit of the earmold since
it has to be sent from the dispenser’s office
to a lab by private carrier or the postal service. Some
are very stiff and can take the abuse of the trip but
can also distend or change the shape of the ear canal
during the impression procedure if the dispenser is
not extremely careful.
Beyond comfort, other factors to consider include
the texture of the ear itself. A very soft ear adds
difficulty to the insertion of an earmold, making the
choice of a more rigid material advisable. An ear canal
that has more cartilage and is “stiffer”
can use an earmold made of very soft materials.
A second set of factors to consider, usually together,
is the power and type of hearing aid and the severity
and kind of hearing loss. A high power hearing aid has
a tendency towards feedback more than a mild gain instrument.
An aid designed for a precipitous high frequency hearing
loss, where the individual has low frequency hearing
within the normal range and a severe loss in the high
frequency speech range, may also tend more to feedback.
As the hearing loss increases and the power of the
hearing aid intensifies, the earmolds have to fit tighter
and plug the ear more. Depending on the slope of the
hearing loss, they can be canal size or half-shell size.
An earmold that fills the entire visible area of the
ear is called a full shell and is often used with profound
or very severe hearing losses.
Hearing healthcare professionals also consider individual
characteristics of their client when they order the
material for an earmold. Lucite, a rigid acrylic is
the one most commonly used and is available in all styles
and various colors. A soft material is sometimes attached
to the Lucite in the canal area to help prevent feedback.
Other choices are: a translucent, flexible plastic that
conforms to the shape of the ear and becomes softer
at body temperature; polyethylene, a smooth, waxy, non-allergenic
material that is fairly rigid and only available in
white; a soft yet durable vinyl; silicone that shares
the softness and durability of vinyl but is also non-allergenic.
People who have allergies, especially to penicillin,
have a tendency to react to certain earmold materials.
They may tell the dispenser that their ear “itches”
or “swells” or “turns red” after
they wear their earmold. It is important for your hearing
healthcare professional to be aware if you have any
known allergies so the use of a non-allergenic product
can be considered.
Aside from the important role they play in managing
hearing loss, today’s custom earmolds appear in
myriad situations to enhance or reduce sound levels.
They provide outstanding noise protection in recreational
and occupational environments. Some noise protection
earmolds containing an acoustical chamber block toxic
noise yet allow speech to be understood. These are popular
with, among others, pro football teams and musicians
and are a boon to industry workers. People who want
to keep water out of their ears can have floatable swimmer’s
plugs made of a super soft water-proof silicone and
that change color or glow in the dark!
Considering the important role of the custom earpiece
in sound conduction and/or noise protection, I offer
the following advice to the consumer in search of hearing
help:
- Ask good questions of your hearing healthcare professional
about the pros and cons of the various styles and
materials in relation to your loss and/or needs and
the reasons for making a particular choice.
- In the process of making an ear impression and/or
earpiece, be patient. Don’t be satisfied until
you and your professional have achieved a fit that
is both comfortable and maintains a seal in your ear
canal. Only then is your hearing aid or personal listening
device truly custom-made.
Margie Littell Ulrich, M.A., CCC-A, is a clinical
audiologist at the Mid-East Tennessee Regional Speech
and Hearing Center in Dayton and a frequent contributor
to Hearing Health and area newspapers and publications.
Related articles:
Earmold Evolution
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