Digital hearing aids are capable of processing sound much
like your music CD players do. That is, the sound is digitally processed to
produce a high quality sound that you hear. The advantage of this
kind of hearing aid is they are set at each individual frequency
(250, 500, 1000,
2000, etc.). This makes for
exacting gain in each frequency.
Programmable aids are those which can have different
"programs" for different listening environments. You can have a program for
quiet environment, noisy, music listening, almost whatever you desire. Many of
these aids have advanced circuitry which allows for amplifying quiet sounds to
where the user hears, and to keep loud sounds from becoming uncomfortable.
Background noise is also reduced with this type of circuit. Speech sounds can
be distinguished from environmental sounds better.
Multichannel aids are those which have the frequencies divided into two or
more channels. These aids also feature the above mentioned circuitry. The advantage of
these is you can more adequately fit a hearing loss which varies greatly from frequency to
frequency, and for people with reverse slope losses. Those who hear high frequency sounds
better than the low. This gives the audiologist more flexibility in setting the aid
correctly to the loss. Some are programmable.
Analog hearing aids are just plain old hearing aids. These will amplify
everything, and I mean everything. Some may have a gain control to keep the sounds from
becoming to loud, but that's about it. These aids usually have no amplification in the 250
or 500 frequencies, due to the upward spread of masking caused by background noise. I
found these type of aids to be noisy, and it was hard to discriminate speech sounds. Some
are better than others, but use your own judgment here. Some kids will need these type of
aids as they can provide more amplification than the fancy ones. Some of our kids need
that. They need as much sound as we can give them.
Nearly all aids made are bootable (direct audio input for attaching FM's
and other listening devices). Always make sure you have aids that have this. Bootable
means the hearing aid has a place on it where you can "boot" an FM system to it.
(Direct Audio Input). There are "boots" or clips that snap into place on the
hearing aid, these are connected to a cord which connects to the receiver of the FM unit.
The child wears the FM unit on his/her body, by means of a harness, fanny pack, or belt
clip. By booting straight to the hearing aid the FM signal is clearer than if it were
being picked up by the T (telecoil) switch or neck loops, which are worn around the child's
neck. There is less interference from other sources by having hearing aids that are
bootable.
