Hearing Aids
A hearing aid is a small device that amplifies sound to
a level that can be heard by people who have hearing damage. There are
many different designs, the most common designs fit around or in the
ear, but there are some that clip to a belt or are worn in a pocket.
Aids have even been integrated into glasses, which was popular in the
1970’s when thick rimmed glasses were in style, but since they
were connected, both had to be used together.
Hearing aids all have similar features, such as the ability to control
the volume of the signal and in some it is even possible to control
the direction of the signal that should be amplified. This is useful
in environments where there is a lot of background noise, the signal
can be focused so that sounds in front of a person are amplified more,
while sounds coming from the side or back are cut. Other features include
noise reduction filters on better digital models that silence background
noises so volume adjustments are not required when going from indoors
to out.
Hearing aids can also be hooked up to other assisted listening devices
through the use of a telecoil. This allows for phones and other devices
to transmit directly to the hearing aid, instead of taking an already
synthesized sound and re-synthesizing it and then amplifying it again
which results in a big loss of signal clarity. A telecoil works by detecting
electromagnetic signals then converting them to electrical signals that
are sent and decoded by the aid. Anything that generates a magnetic
field, such as computers, cell phones and electrical cables, can affect
the efficiency of the coil