Vn. 07-22-99
Mark Ross, Professor Emeritus of Audiology, University
of Connecticut, Storrs, has published and lectured
extensively, in this country and abroad, mainly on topics
dealing with the habilitation and rehabilitation of
children and adults with hearing loss.
Dr. Ross has written, in the IFHOH (International
Federation of HOH) June 1999, an article entitled "Some Reflections on Digital Hearing Aids".
He notes that 16 manufacturers are presently or will
soon be introducing digital hearing aids to the market
place. These aids have a myriad of new features. (Ward's
comment, this market place rush to get into the
fast moving profitable digital sales, means consumers
must be careful and to stay with respected brand
names.)
While noting the remarkable technological advances
this represents, Ross further states, still the
question remains: Has it been demonstrated that this
technological capacity has produced improved speech
perception scores above and beyond that possible with
advanced analog (older style) hearing aids?
He also noted the paucity of
clinical studies attesting to and supporting the
objective superiority of digital hearing aids.
And further quoting David Fabry, audiological
researcher at Mayo Clinic, who discusses, facts,
myths, and leaps of faith, associated with digital
hearing aids. That facts regarding improved
speech perception are equivocal, and exposing some of the�myths (e.g. no need for a volume control,
aids will last longer, cost not an important factor.) He
concludes with his leap of faith -- that digital aids will eventually and unambiguously
improve the speech perception capabilities of more people
in more listening situations than is now possible.
Dr. Ross concurred.
My (Ward's) opinion of what is being said by Dr. Ross
is that one must, at this time, use extra care in acting
on the belief that a digital hearing aid, at a cost of
several thousands of dollars, will resolve hearing loss
problems any better than a quality, well fitted, lower
cost analog aid.
Dr. Ross further bears out a study by Ruth Bentler and
her associates of the University of Iowa. Here, people
were tested in what could be called a placebo test with
the use of hearing aids. In one situation, the people
tried two hearing aids, each for a month. The first aid
was labeled digital. In a second test,
similar digital aids were marked analog.
Meaning, the participants in the test thought the aids
were not digital but analog.
The people were asked to compare their hearing results
of the two aids. With a few exceptions, the subjects
overwhelmingly preferred the aid marked digital. The only actual difference being
their belief that one of the aids represented the cutting
edge of modern hearing aid technology. In tests, the
speech perception scores did not translate into improved
comprehension of speech. These studies show we can be
swayed by our expectations and by clever marketing
appeals.
Ross also adds, I don't mean to rain on anyone's
parade, but we do need evidence regarding performance of
digital hearing aids that is not potentially contaminated
by hopes, expectations or self interest on the part of
either the consumer, the dispenser or the
manufacturer.
Dr. Ross concludes; re digitals, that dispensers are
still in a learning curve, that people trying
these aids should be prepared and not hesitate to return
often for tune-ups.
My (Ward's comment)
Dr. Ross is a gentleman, much more so than myself. I feel
that many dispensers, in spite of their well intentions,
either may not be computer oriented or simply haven't
done their homework enough to assure that your (computer
assisted) initial adjustment will provide the full
benefits of that digital or even analog (often called
digitally programmable which does not process the sound
digitally) computer adjusted aid.
That only by the consumer's participation and
continuing to go back for fine tuning when needed, can
the desired results be maximized. One's ears (over time)
must be the judge, not the person who sold the hearing
aid.
