Induction Loops

What is an Audio Frequency Induction Loop System (AFILS)?

An AFILS is a sound reinforcement system primarily for hearing aid users.

Comprising an amplifier and a single loop of cable enclosing the required area, the loop radiates a low power signal that is picked up by the coils fitted to the vast majority of hearing aids, thus feeding the audio signal direct to the user.

What are the advantages?

Hearing loss often not only results in an inability to hear at a distance, but also impairs the ability to isolate what you want to hear from the background noises. In a typical church these would include the rustling of hymn book pages, people coughing, children crying and other general disturbances. The hearing impaired person will often find these nearby noises completely mask the person speaking through a public address system.

Who does it help?

Those with a hearing aid that has a T position can make use of the loop system. This position switches the hearing aid microphone off, and the pick-up coils on.

What about the rest who may benefit?

Induction Loop Receivers are a compact sub-walkman sized unit with walkman style headphones. People without hearing aids may find listening on the loop an improvement for them. In addition the receiver can help the sound system operator double check that the loop ststem is operational.

Where is the Loop installed?

The cable will generally run either at floor level, or at approximately two metres above seated head height. This ensures that the signal in the users hearing aid remains constant across the area covered. The cable is a thin one, similar in size to domestic telephone cable, and is installed in a discreet manner around the room.

What about Audio Security?

A loop system radiates the signal both inside and outside the loop. For most applications (churches, et cetera) the overspill is not a problem. However for sensitive situations such as court rooms, the loop cable can be laid under the floor covering in a pattern to reduce the spillover to an acceptable level. If this is felt ot be unsufficient, then an alternative such as infra-red needs to be used.

Which loop amplifier do I need?

There are a number of manufacturers of Loop systems in the UK. Ampetrronic are the market leader for low spill systems or where there is a lot of metalwork in the building structure. AVX and "Current Thinking" units are a more cost effective solution, proving to be robust and reliable. They have the advantage of taking an ambient microphone, allowing the congregational singing and general sounds to be fed into the loop, thus reducing the isolation a hearing aid user can feel when listening solely to the loop signal.

All the above manufacturers have a range of products covering a number of loop sizes, from 50 m² to in excess of 500 m². Areas over this can be covered, but need additional hardware and often a number of amplifiers working together.

How much will is cost?

The costs depend upon the existing sound system from which the loop system will be fed, and the size of the building. The building construction technique will make a difference. In addition the length of time it will take to physically install the loop cable will be a major factor. As a guide, a full installation into an reasonable sized room will cost in the region of £850-£1000. However prices start from around £150 for a system suitable for a small room. Under current regulations, exemption from VAT can be claimed for a loop system installed by a registered installer.

Disability Discrimination Act

The Disability Discrimination Act 1995 [overview] applies to all public buildings and came into force on 1 October 2004.

The current legislation requires that, in all public buildings, those who are deaf or who have a hearing imparement are not discriminated against. This means that if you have a PA system to assist those with good hearing then you will need some way of assisting those with poor hearing. This could be a signer at the front of the church or on the video screen, through installing an Infrared System or by the use of an Induction Loop system.

For most applications the provision of Induction loop facilities is the easiest and simplest way of complying with the Disability Discrimination Act as there are many different solutions available.