2. Why Do My Hearing Aids Have To Blow My Head Off?
Dr. Abonso: I don't
see anything missing.
That was a figure of speech. Can you tell me why my hearing aids are often so
loud that I have to turn them down to keep my ears from hurting?
Dr. Abonso: Yes
I can. Your hearing aids are much too powerful: powerful enough to reduce your
I.Q. 10 points in several minutes. You have been wearing these aids for several
Suspicious Consumer: Was that an
Dr. Abonso: No,
just an attempt at humor so you won't fall asleep.
Suspicious Consumer: Why was I
fitted with such powerful aids?
Dr. Abonso: Probably
because your dispenser wanted to make certain you had plenty of gain for
soft sounds and plenty of power for loud sounds. Without plenty of power,
your hearing aids will distort loud sounds.
Suspicious Consumer: But I can't use all
that gain. I have to turn the volume way down to stand these hearing aids and
I still can't hear in noise.
Dr. Abonso: Ah,
yes, they fail the DHTTDGTLWI test.
Suspicious Consumer: The what?
Dr. Abonso: The
Doesn't-Have-To-Turn-Down-Gain-To-Live-With-It test. You have to turn down the
volume controls to live with your hearing aids, which means you miss some of
the quieter speech sounds, which means you can't hear speech well in noise.
Suspicious Consumer: You got that
right! And if I turn the volume controls up, the loudness hurts.
Dr. Abonso: Your
dispenser really should have checked to be sure that the maximum output of your
hearing aids didn't exceed your discomfort level.
Suspicious Consumer: Can I buy
hearing aids that pass your funny Ditto--whatever test?
Dr. Abonso: Yes
you can. Since 1990, many hearing aids have used a tiny high-fidelity amplifier
that can be adjusted so that it only amplifies quiet sounds. Loud sounds are
allowed to pass through without amplification, just as if the hearing aid wasn't
Suspicious Consumer: What about
these programmable hearing aids I read about; do they do that?
Dr. Abonso: A couple
of them do.
Suspicious Consumer: Are you being
coy? Which ones do? And why don't all hearing aids amplify only quiet sounds?
Dr. Abonso: I'll
tell you which ones, but I don't want you to think my only purpose in life is
to promote a particular brand of hearing aid. The high-fidelity amplifier I
mentioned is called the K-AMP circuit. Some 32 hearing aid companies now make
hearing aids using that circuit. The (more expensive) programmable aid that
usually does the best job is the RESOUND aid. That was a wheelbarrow full of
electronic equipment at Edgar Villchur's research lab back in the 1970's. It
is now wearable due to $20,000,000 of development at AT&T Bell Labs and
Suspicious Consumer: You forgot
my last question. Let me rephrase it: Why don't my hearing aids amplify only
Dr. Abonso: Some
hearing aid dispensers are more familiar with the old head-banger designs and
keep ordering them.
Suspicious Consumer: Why don't
the manufacturers simply stop selling those old aids?
Dr. Abonso: Because we
live in the U.S.A., where customers tell manufacturers what to do, not vice
Suspicious Consumer: You do get
off the track. How would I know which hearing aid is best?
Dr. Abonso: Ultimately
you must decide that yourself. Be sure to go to a hearing
professional who will give you information you can trust.
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