| Hearing
instrument technology has come a long way in the last few years,
thanks to the computer microchip and digital circuitry. Here are
some of the latest innovations.
Digital Technology
Why does music from a CD sound more crisp, clear, and distortion-free
than music from a record or tape? The answer, at least in part,
is the difference between analog and digital sound processing.
Digital hearing instruments have one or more microchip processors
inside them that convert analog sound waves into the zeros and ones
of computer language. Sound in this format can be processed more
quickly and more efficiently than analog sound waves; in fact, incoming
sounds are sampled at a rate of a million or more times per second.
The digital instrument’s circuitry analyzes these sound levels
and frequencies, manipulating them to provide a more efficient match
to an individual’s hearing profile.
For example, a person with hearing loss may have trouble hearing
soft sounds, but when some sounds are amplified even a small amount,
they become uncomfortably loud. Hearing instruments with digital
compression circuitry are able to stratify incoming sounds, detect
those that need amplification from those that don’t, and process
the sound accordingly.
Programmable Technology
Digitally programmable hearing instruments, which are different
from fully digital instruments in that they’re not equipped
to process all incoming sound digitally, offer the very useful benefit
of being able to sculpt sound to fit a particular individual’s
unique hearing profile, and can be reprogrammed if there are changes
in hearing loss. Your hearing professional can program the instrument
with multiple channels, enabling you to preset and store several
different programs, each sculpted to a particular set of sound environments.
You can then select the appropriate program using a button or remote
control unit: normal conversation, concert hall, office, or telephone,
are some examples.
Feedback Reduction Technology
Feedback has long been a problem for hearing instrument wearers.
Now we know a lot more about feedback, and have developed ways to
deal with it. Feedback happens when amplified sound waves escape
back out through the ear canal and are then re-amplified by the
hearing instrument—resulting in the high-pitched squeals that
set your teeth on edge. Smaller, in-the-canal styles of hearing
aids place components closer to the eardrum, preventing sound waves
from escaping, thereby reducing, and often eliminating, feedback.
Some new instruments are also able to detect these sounds before
they become audible and cancel them out, greatly reducing this frustrating
problem.
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