What is a hearing/induction loop?
Only quality controlled loops are fit for the future. The international standard for Audio-Frequency Induction Loop Systems is IEC 60118-4.
A hearing loop system helps hard of hearing people who use a hearing aid, loop listener, and cochlear implants to hear sounds more clearly by reducing or cutting out background noise.
The hearing loop is a special type of sound system for use by people with hearing aids. The loop system provides a magnetic, wireless signal that is picked up by the hearing aid when it is set to the T (Telecoil) setting.
The loop system consists of a microphone to pick up the spoken word; an amplifier that processes the signal which is then sent through the final piece; the loop cable. The loop cable is a wire placed around the perimeter of a specific area i.e., a meeting room, a church, a service counter, etc. to act as an antenna that radiates the magnetic signal to the hearing aid.
At home, for example, you could use a loop to pick up sound from your television, hi-fi, or radio. A loop can also be set up with a microphone to help hearing aid users hear conversations in noisy places. In the theatre, a loop can help you hear the show more clearly. A loop cannot be used to give stereo sound. If this is important, you should consider using an infrared system.
Coverage and supply of sources
An important requirement for rooms other than cinemas is that the loop system should cover not only the area for the audience but also the podium or any other area used by speakers/performers. The usability of the loop system strongly depends on the source that feeds the system. There should be a sufficient number of microphones to catch the sound. Not only the main speakers/lecturers but also from speakers on the floor asking questions etc.
Desktop and counter loops
A desk loop is a small induction loop placed on or under the desk or at counter windows, covering a small area. Desktop/counter loops are important for communication in ticket offices, at information desks, in hotels, banks, the post office, pharmacies, and chemists, as well as other retailers, and make it possible for hard of hearing people to receive information privately and without misunderstandings.
This is of particular importance concerning ticket offices and information desks at public transport terminals, where the acoustic environment is often very bad and affected by high levels of background noise and echo.
How do induction loop systems work?
An induction or hearing loop is a cable that circles the listening area. An electric current is fed to the loop by a loop amplifier. The amplifier gets its signal from a microphone placed in front of the person speaking or by means of a direct connection from another sound source, such as a sound system. The resulting electric current in the loop produces a magnetic field, which corresponds to the sound. You can then pick up this magnetic field if you are sitting within the area of the loop and your hearing aid – or loop listening aid – is switched to T. You will need to adjust your own hearing aid for volume.
In addition to loops covering a room/church/assembly hall etc., loops can be used on counters and as a neck-loop. The latter is often used as a personal assistive device, which can be combined with other transmitting technologies like FM and Bluetooth.
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