Digital Hearing Aids
Digital
hearing aids boast today's most advanced technology. Digital hearing aids
are programmable hearing instruments with digital circuits. These digital
circuits are more flexible than analog circuits. They can be precisely
programmed to match the patient's individual hearing loss, sometimes at
each specific frequency/pitch. Digital circuits offer improved clarity
of sound, less circuit noise, faster processing of sound, and improved
listening in noise when compared to analog circuits. Digital hearing aids
are easy to use because they adjust volume automatically.
Digital hearing aids
- introduction
Digital hearing aids have been the cause of excitement and many questions.
Basically, digital hearing aids process sound digitally. This
means that ehe sound that you hear will be clear and free from distortion.
Digital hearing aids represent the most advanced technology available
today allowing the most precise prescriptive fitting available. Where
older analog hearing aids turned everything up, digital hearing aidS focus
on bringing understanding through sophisticated control of the sound signal
inside the hearing aid. If you think about the sounds that you can hear
and sounds that you cannot hear, these sounds differ in pitch (ex. keys
on a pianoj) and they differ in volume/loudness. Digital processing can
shape your amplification (volume and clarity of signal which you hear
through the aid) across changing pitches and changing volumes.
Hearing
loss is usually not the same degree across changing frequencies/pitches.
Due to changing hearing levels at different frequencies, each
specific frequency needs a different amount of amplification. Digital
hearing aids separate the frequency response into bands and channels,
which can be manipulated independently, customizing the hearing aid response
to your specific hearing loss. They can examine the sound environment
and adapt the amplification accordingly without adding noise or distortion.
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How digital hearing aids differ from conventional
hearing aids
Conventional hearing aids increase the volume of all incoming soundS,
sometimes making loud sounds too loud and soft sounds too soft, many times
adding distortion and noise. To some extent, comparing a digital hearing
aid to a conventional hearing aid is like comparing a compact disc to
a record player.
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How digital hearing aids work
In a very rough sense, the digital hearing aid has five major components:
the microphone, the analog to digital converter, the core, the digital
to analog converter, and the receiver. Sound waves hit the hearing instrument
microphone where they are converted to an electrical signal (analog).
The signal then passes through an Analog to Digital converter (A/D converter)
where itis changed to a sequence of 1s and 0s. This sequence is sent to
the "core" where it is filtered into bands and channels, then
manipulated according to the programmed settings for the specific hearing
loss. The manipulated signal is then channeled through a Digital to Analog
converter (D/A) where the end result is an analog signal that has been
manipulated according to the hearing loss. This signal then travels to
the receiver where it is converted back to an acoustic signal that the
user then hears. In other words, the digital hearing aid has a tiny computer
chip in it that can manipulate the sound according to specific frequency
(pitch) and specific volume level to deliver a clear sound set precisely
to the user's hearing loss.
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There are several factors to think about when selecting a digital hearing
aid:
- Number of channels and bands
- Professionals' expertise
- Directional
microphone
- Multiple memories
Learn more about selecting
digital hearing aids »
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Costs of
digital hearing aids
If you have been thinking about digital hearing aids you will know that
they are expensive. The cost of one digital hearing aid can range from
$1700 to $4,750 at the retail level. one reason for the high price is
the time and money manufacturers put into their research and development.
A great deal of research is necessary before a hearing instrument is released
to the public. With miniaturization and computer chips, it is understandable
why digital hearing aids are more expensive than other types.
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