Ampetronic are the market leaders in the development of induction loop systems for the hard of hearing. With thousands of installations all across the world and Ampetronic representatives on many industry advisory boards in Europe, you can be assured you are using the best the market offers.


There are 6 basic types of loop layout for an audio induction
loop system, detailed in the following sections.

What is an Audio Induction Loop?

An audio induction loop is a way of transmitting sound through a simple wire loop to a suitable receiver. They are used most frequently to help hearing aid users listen to a sound source more clearly where there is background noise in a room.

How does an Induction Loop work?

In a very basic form, an induction loop system consists of a loop of wire around the edge of an area connected to a special amplifier. The input of the amplifier is connected to the sound source that the hard of hearing users want to hear more clearly.
The amplifier drives an audio current (not voltage) through the loop.

This current generates a magnetic field in the area enclosed by the wire that a suitably fitted hearing aid can receive.

Choosing a Loop System

Counter Loop / One-to-one Systems
For counters, recption desks, ticket counters and one-to-one communications.
- Simple loop coil, usually vertically mounted
Cancellation loop
For controlling spill in one direction only, for back to back rooms to prevent interference.
- Single loop with carefully designed 'figure of 8'
Perimeter loop
For rooms up to 20-25m wide with no metal present, or rooms 2-5m wide with metal present. Usually only possible for smaller rooms in modern buildings.
- Simple loop of wire around room / area perimeter
Low loss phased array
For areas where a perimeter loop is not possible. Any area >20-25m wide, or rooms with metal loss, provides limited spill control.
- Two loop patterns overlaid. 90 degree phase shift
Single array
Rooms where a perimeter loop is not possible, usually due to metal losses. Only suitable for fixed seating applications.
- Simple loop laid as individual consecutive segments.
Ultra-low spill phased array
For the true control of loop spill to 1.5m from loop edge, 3.5m above and below. For confidentiality and for adjacent loop systems. Excellent for metal loss.
- Two loop patterns overlaid. 90 degree phase shift



Steve Marshall
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