Connevans equipment for deaf people

Induction loop 'T' pickup - FAQ's

How does a hearing aid 'T' pickup work?

A hearing aid 'T' pickup facility is an alternative to using the 'M' microphone sound input.

When the 'T' or Telecoil facility is selected on a hearing aid, the microphone is (usually) turned off and a small pickup coil selected instead. This small coil is able to pick up changes of magnetic signal. When the coil is in a magnetic field which is varying in response to sound the coil will convert the signal back to sound.

The induction loop wire is fed from a loop amplifier - or in the case of a neck loop the headphones socket. The sound is 'amplified' and the resulting electric current in the loop wire produces a magnetic field, which corresponds to the sound. A deaf person wearing a hearing aid can then pick up this magnetic signal with their hearing aid switched to the 'T' setting.

If you were looking at how a loudspeaker works in simplistic terms you would find a magnet frame structure with a suspended floating inner thin panel or cone. The cone includes a coil and just as with an induction loop, when connected to an amplifier, current flows and produces a magnetic field in the coil. This magnetic field varies as the current from the amplifier varies. As the current changes direction it moves the cone in and out - the cone effectively vibrates. The moving in and out of the paper cone moves air and produces the sound waves that we hear. In a loudspeaker the varying magnetic field moves a cone which generates sound whereas with an induction loop the varying magnetic field is picked up by the hearing aid Telecoil aid which produces the sound into the hearing aid
... magic eh!

In general terms the sound from the loop is the same whether you are at the front or the back of the room. Using a loop is a definite advantage in a large meeting room compared to listening using the hearing aid microphone. With a hearing aid microphone the level and quality of sound reduces the further you are away from the sound source.

Some advantages.

An advantage of using the 'T' pickup is the reduction of general background noise. In a large area loop, such as in a village hall, you would be able to listen directly to a presenter without the distraction of coughs, shuffling feet or other noises read further information here.

When listening to a telephone which has a Telecoil facility, via a hearing aid on 'T', because the microphone is turned off you are much less likely to get feedback 'whistle round', in fact you may be able to set the hearing aid volume louder than usual read further information here.

When listening to a telephone which has a Telecoil facility via a hearing aid on 'T' because the microphone is turned off you will hear much less general environmental sound than usual. This is a particular advantage in public places which have high road noise or in a railway station.

Using headphones over a hearing aid is neither comfortable nor will give good sound quality, a personal inductive listening product will give a much better sound - read further information here.

Using a wireless radio aid with a neck loop (or direct input) allows a hearing aid user to hear sound from a distance with greatly reduced background noise - read further information here.