The Current Thinking
range of audio frequency induction loop amplifiers (AFILS)
represent the some of the latest advances in
induction loop technology and have been designed by
a team with over 20 years experience in the design
and production of loop equipment.
The range covers all sizes of installation from
portable units for customer service operators, small
fixed units for counters in banks & Post Offices to
the largest auditoria using multiple amplifiers and
phase shift controllers.
Were Do I Need Induction Loop
Facilities for the hard
of hearing are required by both the building
regulations document M and by the DDA (Disabled
Discrimination Act) in places where the public need
to hear information, or where customers are
separated from staff by a glass partition (for
further details see our guide to Induction Loops).
An Induction loop amplifier will satisfy the
requirements of both pieces of legislation with the
minimum of fuss, and without the need to hire and
How Does It Work?
An induction loop
amplifier take audio from microphones and other
audio sources, such as mixing desks and CD players
and mixes them together. The amplifier then
processes the audio using a compressor limiter to
ensure that the sound has a fixed dynamic range (so
quiet sounds are amplified and loud sounds are
attenuated to prevent amplifier overloading). The
processed sound is then passed to an output stage
which converts the audio voltage to a current. This
current then passes through a loop cable placed
around the perimeter of the area to be covered. This
current generates a magnetic field which is picked
up by a coil in the hearing aid, and converted back
to audio. Induction loops use no modulation, and are
exempt from radio licensing, they also have the
great advantage that the user maintains his or her
Induction loop amplifiers are used to provide audio
coverage direct to hearing aids fitted with a
Telecoil, all NHS and most private hearing aids are
equipped with the T position switch, including
digital Hearing Aids.
position is provided for telephone use and all
IEC118-1 compliant aids have the coil.