Induction loop systems for hearing aid users

Audio Frequency Induction Loop Systems

Induction Loop System for the Hard of Hearing

Audio Frequency Induction Loop Systems (AFILS) are installed in places where hearing aid users will benefit from direct sound input to their personal hearing aid. The user switches their hearing aid to the “T”-position (Telecoil) – this reduces background noise and increases clarity of speech information and the enjoyment of live sound. The direct sound may come from dedicated microphones and/or the microphones used for a sound reinforcement (loudspeaker) system.

Microphones for Audio Loop Systems

Hearing aids have microphone(s) built-in to them. The loop induction system is simply a way of transmitting sound directly to the hearing aid. This is only of benefit to a hearing aid user, when the microphone(s) connected to the loop system are better placed to to the source and therefore pick up less unwanted (ambient) sound than the microphone(s) built into the hearing aid. Ideally, microphones should normally be less than 1 metre from the talker in quiet locations, and as close as 300mm in some noisier environments. In theatre (stage) applications, this can be up to several metres, but only when the actors project their voices and the background noise level is low. If more than three microphones are used for speech, then an automatic microphone mixer is desirable, as recommended in Standards for best practice.

Examples where a loop system is used

  • A bank counter. The speech from the bank counter clerk comes through a ‘window’, but the hearing aid microphone is in the open plan area, where there is other noise. A microphone near the bank clerk is much better located to pick up ‘wanted’ sound, and with less general noise from the bank area. This also avoids the clerk having to raise their voice, which would otherwise mean other people may hear the conversation. (see also, Speech Privacy Systems).
  • A church. The hearing aid user could be anywhere in the congregation, but a microphone(s) at the pulpit, lectern, or a tie-clip mic on the minister, is much better placed than the internal mic which is on the hearing aid where the user is sitting. More ‘wanted sound’, less ‘unwanted’ sound from background noises in the church, and less reverberant sound.

A hearing aid loop fed by a microphone that is much better placed than the hearing aid’s internal microphone, will be of significant benefit to the hearing aider user.

Value Added Tax (VAT)

Supply of induction loop equipment may qualify for VAT relief when purchased by registered disabled persons, or for the exclusive benefit of hearing aid users by a registered charity or equivalent church organisation. Please note that relief does not extend to a public address system. Contact us for details or see VAT Notice 701/7 at www.hmrc.gov.uk.

If you need…

  • To Know How to Choose an Induction Loop System for places with public access or in the workplace to comply with the requirements of the The Equality Act 2010 (Disability) Regulations 2010
  • A Design or specification for an installation of an Audio Frequency Induction Loop System – we own calibrated test equipment and proprietary CAD prediction software
  • A Loop System Design, perimeter, counter or “low spill”
  • Testing & calibration of an existing installation for compliance with British/EU Standards and ongoing maintenance
  • Alternative solutions, Infra-Red or Radio transmission
  • Make an Enquiry…..

Equipment

We supply loop amplifiers from Ampetronic, Univox and AVX. You may also consider using a wireless transmission system with personal neck loops where the installation of a perimeter loop or complex (low spill)  loops are impractical – these can use infra-red or FM radio (Sennheiser Infraport and Listen Technologies infra red and FM).

We are happy to advise on the most suitable technology for your application.