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Musician Speaks Out on Hearing Aids!
My name is Rick Ledbetter. I am a bassist, composer and music
producer. I have a computer based music composition and digital
audio production studio, and, I have been in music six I was
six. I have a formal music education an learned audio production
from some of the best in LA. (If you are wondering, I work
with headphones and use another persons ears when I need
it) My loss is an inherited late onset, and is stable. I am
in 53, and my father passed away with only about ten percent
of his hearing left. About twelve years ago, my hearing started
to degrade over a span of three years; it has stopped deteriorating,
and is more or less stable. I first purchased a set of analog
hearing aids, but they were useless, and they wound up in
a drawer. I later went to analog aids with a K-Amp, which
were much better, but not very good for music.
About two years ago, I upgraded to digital CICs on the advice
that they would be superior to my analog aids for sound reproduction.
My long-suffering audiologist (and I hope he is reading this
and knows how much I appreciate him for putting up with me)
tried his best, but simply did not have an acoustical environment
to set up the aids for hi fi music reproduction. The initial
fitting sessions were hit and miss, and frustrating for both
of us. Since I am familiar with music production, computers,
and have a lot of sound generators, he was kind enough to
let me borrow the interface on the weekends and let me learn
how to adjust the aids myself. After about a year of trying
to get the aids adjusted right, I finally switched off all
compressors, NR, limiters, etc, set the output limiter to
hard limit (in my brand of aids, even though the limiter is
set to 0db, it is still on, no matter which type of limiting-
multiband, broadband or hard limit, is chosen) and set the
EQ for the best music fidelity the aids could reproduce. Since
these aids are two channel, I have the second channel set
up for speech in difficult situations, with a minimum of upper
end compression. Channel one is my music channel, and I use
it almost all of the time.
While I was learning to adjust my aids, I accumulated a bunch
of observations, experiences and ideas, and I am passing them
on in the hopes that someone will profit from my situation.
Digital aids do not have a "sound" any more than a home stereo
has a "sound". OK, a home stereo is dependant upon the speakers,
but that is less of an issue here. The "sound" is dependant
on the EQ (tone controls) and various compressors, noise reducers,
speech enhancers, and limiters in the aids. The reason aids
sound different is because of the settings made when they
are shipped. Think a car stereo with the bass turned all the
way down- you have to adjust it to your liking.
Most aids manufacturers make their aids with limiters permanently
on, and others use different types of compressors, but, by
and large, the digital sound amplification process is the
same from company to company. Aids are created, and the dispensers
are trained, from the standpoint of speech recognition. This
was an acceptable model with the older analog aids, but this
model does not apply to digital aids, which are high fidelity
sound reproduction devices, and should be fitted as such.
The aids makers often do not provide enough information for
a dispenser to adjust the aids beyond a series of templates
based upon the wearers hearing loss and optimum speech recognition,
and I know of dispensers that are displeased with the makers
for not telling them everything they need to know about fitting
the aids. I believe that the makers could be doing a lot more
to rectify this, but Audiological association could be doing
more to bring its members up to speed and making sure they
have the equipment and knowledge to fit digital aids. I believe
the makers should provide more training and certification
for dispensers... And I do not mean taking a multiple choice
test to see if they know the product literature and can parrot
the figures, but making sure that the dispenser knows what
all of the controls are, what they do and how they interact.
And most importantly, what the aids sound like. The dispenser
needs a real worl acoustic environment to set the aids,
with good speakers to reproduce sound, a strong enough amplifier
to recreate real world decibel levels, and an acoustically
adjusted room in which to fit the aids. Face it, you can not
get an idea of what your aids will sound like when you are
sitting in a hard walled office, listening to a 3 inch computer
speaker play back a tinny recording of a music clip. I have
had a number of HOH people contact me in total frustration
because their dispenser is not achieving the right adjustment
and is attempting to characterize the patient as "difficult"-
hardly a constructive approach. I believe this attitude, and
any other statement or action that damages the patients confidence,
and reflects on the dispensers incompetency, and any dispenser
who treats the aid wearer with disrespect and condescension
should be barred from selling aids.
The person with a hearing loss is already trying to deal
with a sense of isolation and inadequacy without having the
person they depend on to fit the aids contributing to it.
The statistics showing that a lot of aids wind up in a drawer
does not always reflect upon the wearer- it also shows the
inability of the dispenser to properly fit the aid. Dispensers
are accustomed to working with older, uniformed aid wearers,
and they are not always prepared to answer specific technical
questions about the aids. In my experiences of listening to
the complaints of many other aid wearers, there are dispensers
who tend to get defensive (I am lucky- mine did not) when questions
are asked that are beyond their training. This generates an
atmosphere of distrust when the aids wearer realizes that
the dispenser does not know the answers or the solutions.
It is odd that a degree in audiology does not mean adequate
training in the fitting of hearing aids. The curriculum treats
aid fittings as a course elective of minimal hours. Therefore,
the aids dispenser must get training from the hearing aid
maker, and a process of self-education. Many dispensers feel
that the aids makers are not teaching them enough about the
digital aids and how to fit them, beyond the use of templates.
If you go to the web sites for aids, and you will find a lot
of vague superlatives and good web site design, but no data.
And no prices either, but that is for another day. And if you
go to the support sites for the HOH, and you will have to
search long and hard for information about how to choose an
audiologist, what questions to ask, and practical information
about digital aids and their fitting.
The following is my two cents worth, comparing digital aids
to quality sound amplification: The most important feature
of hearing aids is the number of EQ bands (tone controls),
and the ability to reproduce both low and high end frequencies,
and I mean from as low as 125Hz to as much as 10Khz. The low
end can be helped by a bigger vent, but at the cost of risking
feedback; most aids ignore bass loss, and make no attempt
to amplify it until around 250hz. To give you an idea, the
sound of a drum kitÕs bass drum, also called a kick drum,
happens from 80 Hz to 120Hz., and an electric bass has a frequency
range that begins at 32 Hz. An upright bass has a low frequency
at 42Hz, but the body will create a thump an octave under
that. Got the idea? If you have an aid with a small vent,
needed to reduce feedback potential, you will block out the
low frequency sounds, so, somehow, the low end needs to be
reproduced. I would choose an aid with at least ten bands
and the widest frequency for those bands as the first requirement,
and discount a lot of speech enhancers and noise reduction
in favor of a quality multi band compressor, and output limiter,
sparingly used. The problem with using compressor- expanders,
limiters, etc., is that they reduce volume differences- kind
of like what happens on the radio- all sounds are pretty much
at the same volume. And this is not natural. Who wants to
hear a songbird at the same volume as a passing Harley-Davidson?
Granted that a hearing loss is marked by a narrowed range
of difference between loud and soft, and a greater sense of
perception in volume differences, but still, the aids should
have a sense of difference in volumes. This, along with sight,
is how we judge spatial placement and orientation.
Probably the hardest part of adjusting aids is translating
sound into terminology: What is "tubby", "harsh", "shrill",
etc. This is where the aids wearer has to pay attention to
what the aids are reproducing, and be able to tell the audiologist.
I found that the initial setting is close, and, once all of
the limiters, enhancers, etc. are off, reducing 1KHz, 1.5Khz,
and 3Khz, one notch each, then increasing 250Hz and 500Hz
one notch will more or less get the aids to sounding "real".
Here is a rough approximation of terminology of sound and
frequency: Thuddy is 250Hz, Boomy is 500Hz, Muddy is 750Hz,
Clacky is 1Khz, Harsh is 1.5Khz, Shrill is 3Khz, Piercing
is 4Khz, Zingy is 6Khz. Please keep in mind that this wonÕt
always be the same from wearer to wearer, but it is a start.
And note that the EQ bands are interactive: if 3Khz is too
shrill, but bringing it down loses too much treble, then bring
down 4Khz and see if this helps. If you find that you canÕt
hear consonants well, then reducing the lower frequencies
will unmask them. The beginning point is always balancing
the aids: a tedious process of making sure the eras are hearing
frequencies well in both sides at the same time. I do this
with the help of a sine wave generator in my studio, listening
to one tone at a time, until they are balanced. I have found
that I will misbalance treble and bass, but once the ears
are hearing in left- right balance, it is a lot easier to
raise or lower each frequency on both sides until the overall
EQ curve is pleasing.
The aids makers have put so many "bells and whistles" in
the aids that they have lost focus of what the aid is supposed
to do- provide "normal" sound reproduction. Any music producer
will tell you that you start with a good tone setting (EQ),
to enhance the sound, and then carefully bring in the compressors
and limiters, but only as devices to do what the EQ cannot
do. They know that it is impossible to achieve the best sound
while trying to adjust EQ, limiters and compressors all at
the same time, because of the way they interact with each
other. But the aids makers expect a dispenser to fit an aid
with a generic template, which includes having all sorts of
noise reduction, limiters, and compressors going at the same
time In my personal experience of adjusting my aids, I have
found that most of the noise reduction and compressor- expanders,
et al., are of limited usefulness. I think they are more distracting
than they are useful. I was bothered by their constant self
adjustments- sounds disappearing, others getting louder, some
appearing out of no where. I found that most of the offensive
noise was generated by over boosting the speech frequencies.
If those are over boosted, then limited, then enhanced, then
all you are doing is slapping one band-aid on another. You
must begin with a good sound.
And while I am on a tear- I believe that a CIC is the best
choice, because it uses the outer ear to help the aid give
the wearer a better sense of "real". Some seem to think the
choice of a CIC is cosmetic, but, the deeper the aids microphone
is in the ear canal, the better the sense of sound placement
and what is "natural" will be. You are used to hearing with
your outer ear shell, so why not make things easier and use
it? I think that aids makers should figure out how to get
the mike and speaker as far down in the canal as possible,
even if the works have to be placed behind the ear. Setting
the aids must be done in increments, to allow the brain time
to adjust. This means making adjustments and seeing how they
work in the real world, and the process is tedious can take
weeks. Since the bulk of audiologists do not have a listening
environment to set the aids, then the wearer must go through
a long process of hit and miss. It would be much better for
an aids maker to produce a loaner hand held adjuster, which
the aids wearer could take home. From the aids wearers point
of view, this means an adjustment can be made when desired,
without the trouble of booking an appointment, and from the
dispensers point of view, this reduces to number of follow
up adjustments dramatically. And I think that finding the
right setting can take as much as three months, and the wearer
and dispenser should allow at least three days in between
readjustments, and set the aid wearer on a regular visit schedule,
more often at first, for fitting the aids. There is no reason
that a wearer cannot learn to adjust their own aids, and likewise,
I think that the interfaces should be made available for home
adjustment for those who are willing to learn how. But we
must educate ourselves about sound and our loss, so that we
can relate to the dispenser what we need to hear in our aids.
They can only guess, and if we canÕt describe what we need
to change, they will have no way of finding it.
And finally, it is up to the aids wearer to educate him
or herself about Digital hearing aids, their individual hearing
loss, and what good sound is and how to achieve it. It will
be frustrating and a test of your patience, but you must be
patient- this will take time. It is not as daunting as it may
seem, but it is necessary for you to be able to work with
your audiologist / dispenser to achieve the best possible
setting for your aids. And one big caveat here: what sounds
good to one person does not sound good to another- whether
we are talking about car stereo, hearing aids or even a concert
hall. One I found the setting that I liked on my aids, I spent
some more time tweaking the EQ for my personal preferences
and needs. For instance, I like a bit more bass, so I had
the 250Hz up a bit. For those that take it upon themselves
to get their digital aids adjusted correctly, I hope that
you are able to reach this point where you can fine tune your
aids to your lifestyle- with digital aids, it is possible.
Please excuse the redundancy in my musings- I am not much
of a writer, but I hope I got some points across and managed
to answer a few questions. If I can be of help, please feel
free to email me. smalldog@triad.rr.comRick Ledbetter ©2002
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