Have you heard...Loop systems

The Hearing Loop System is a special type of sound system for use by people with hearing aids. It is important to know how loop systems tie in with sound systems in general, since they are frequently used together. This article will also include guidance on how to specify your own loop system and other general aspects of loop systems.

Sound systems for use in public places are generally used to reinforce or relay sound to a hall, church or auditorium or to other parts of the building from some central point.

Sound is said to be reinforced when the audience can hear the original sound (eg from stage or rostrum) both directly and via the sound amplification system. Hence the term sound reinforcement.

A sound system may also relay sound to areas of a building where the original performer, speaker or musician, cannot be heard without the use of the sound system. This may be used, for example, in a large sports arena or to relay speech or music to different parts of a building where the sound source is out of earshot. This type of a system is known as a public address system.

Any sound system may also incorporate a hearing loop system. Ideally they will be used together, as a fully integrated system.

A simple, complete sound system will comprise five main elements: at least one microphone, one sound amplifier, one loudspeaker, one induction loop driver and one induction loop cable. 

How the Hearing Loop System works

• Sound is collected by one or more microphones.
   
• The very small electrical output from these microphones is mixed with any audio required (e.g. CD player) and fed to the Induction Loop amplifier, usually referred to as an induction loop driver.
   
• The loop amplifier drives a powerful current through the loop, which changes with the variations in the speech or music patterns. This sets up similar patterns of speech or music in the hearing aid by magnetic induction. The hearing aid must therefore be switched to 'T' when using a hearing loop.
   
• In this way, any sound picked up by the microphones or from other sound sources, whether speech or music, is heard directly and clearly in the hearing aid.

Remember that loop systems are available anywhere that displays the loop symbol:

Dont forget to turn your loop function (T) on your hearing aid on, if you don't have one ask your Audiologist why not!