Article
Apr 2009
Cerumen Management for Hearing Aids
Nothing damages an ITE, ITC, or CIC style
haring aid faster than ear wax accumulating in the sound port. Every time
the device is inserted into the ear the canal tip acts like a plow,
scooping cerumen right into the sound outlet where it can cause all sorts
of problems, such as weak or distorted sound, intermittence, or complete
instrument failure requiring receiver replacement.
Ear wax is a natural healthy occurrence of
the human body, so the only methods for eliminating wax from the hearing
aid are either a proactive approach – trying to keep the wax out, or a
reactive approach - trying to remove the wax once it is in.
In this article, we’ll look at a few
proactive approaches, as well as pros and cons of using each. I’ll even
give you my pick as to which device I prefer, and why.
Wax spring:
The wax spring is a small metal device that fits inside the sound outlet
port tubing (receiver tubing). Calling this device a spring doesn’t really
do it justice as it isn’t a spring at all. But it looks like a spring in
the sense that it is one piece of metal wound in a circular spring
fashion. If you take a good look at it under a microscope (or if you’re
near sighted vision is very good) the shape will resemble a bee’s nest.
The purpose of this device is to keep ear
wax from entering the sound port by blocking and collecting it inside the
receiver tubing before it reaches the sound port where it can cause
damage. The spring design allows sound out while the device blocks and
collects wax. The spring can be installed in seconds using tweezers and
pushing the spring into the receiver port. It is very effective and will
keep almost all debris from entering the receiver, but it can get clogged
rather quickly and need replacement. Replacement can be performed by
pulling the used spring out and inserting a new one.
Pros and Cons:
The Wax Spring is small and can be used in short canals or CICs when there
isn’t enough space for other options. It can be installed in seconds in
the office, so if a patient comes in with a wax problem they can leave
with a solution. The downside is the device will absolutely need
replacement at some point. It is intended to trap and collect wax and
debris and there is no method of maintaining the device (other than maybe
a vacuum pump – more on that in a future article) – replacement is the
only option, and that should be performed in the office.
Flip-Top Wax Guard
The Flip-Top Wax Guard (also refereed to as a Toilet Seat Wax Guard) is a
device that uses a small door to cover the sound outlet port at the canal
tip to keep the wax out. The door has a hinge on one end so it can open
and expose the sound outlet for cleaning. A space around the circumference
of the door allows sound from the receiver to be delivered unaffected.
This type of wax guard is typically installed from the manufacturer,
however someone with good repair and modification skills can install in
the office.
Typically, any cerumen will collect on the
outside of the door, blocking it from entering the sound outlet port, or
receiver. To clean, the user would simply open the door and brush away the
wax.
Pros and Cons:
The nice thing about the Flip-Top Wax Guard? – It is a permanent
component. It doesn’t need replacement and it will work the same way in
several years as it does when it is new. And it is easy to use. I also
like the idea of keeping the wax completely external to the hearing aid.
The downside is the user's commitment to cleaning their hearing aid every
day. If any cerumen has a chance to accumulate, it can push around the
opening of the wax guard and migrate into the receiver
C-Guard
The C-Guard is a special wax
protection device which uses an acoustically transparent membrane and a
special receiver with a barometric relief vent The idea is for the cerumen
to collect on the membrane and then be wiped off daily by the user. The
membrane is made to be replaced occasionally by the user. This is a system
installed by the manufacturer.
Pros and Cons:
The C-Guard is easy to maintain by just wiping daily – definitely a plus.
The user replaceable membrane though could be a pro or con depending on
who is doing the replacing. Some users can handle a chore like this with
ease, while others may experience problems. Plus keeping track of small
parts and a special tool for installing them could also be a headache. The
special receiver and relief vent are a bit of a drag for me. I always
think about future repairs and modifications and anytime you have special
parts involved your options are limited.
So, my favorite wax guard protection is
(drum roll please…..): The Flip-Top Wax Guard. I like the fact that there
are no replacement parts, and if used daily will keep everything out of
the sound outlet port. It is a proven system that has been around for a
long time.
However I do need to give an honorable
mention to the Wax Spring because there are times when the Flip-Top Wax
Guard cannot be used, such as with most CIC devices. Sometimes there isn’t
enough room in the canal to accommodate it. Therefore, the Wax Spring is
at times a logical option – given the fact it will eventually need
replacing.
Next time, we’ll look at reactive
approaches to cerumen in hearing aids, and how those methods can interact
with wax protection systems.
About the Author
Chris Perkins is the owner of Lightning Enterprises, and facilitates
the Lightning Enterprises newsletter. He has worked in the hearing aid
industry since 1991 in hearing aid manufacturing and product development,
as well as equipment and process consulting.
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