The induction loop system enables an audio frequency signal such as speech or music to be transmitted to a listener by means of a magnetic field. The field may be picked up by a variety of means such as standard type hearing aids, or dedicated loop receivers. Direct transmission helps to improve intelligibility for hearing aid users by reducing reverberation and background noise.

The principle of operation is that a current flowing in a wire creates a magnetic field around that wire. This field is then received by a small coil in the listening device and amplified. The pickup coil in a hearing aid is normally selected by a switch marked M for microphone, and T for coil.

The loop comprises of one or more turns of insulated wire laid around the listening area fixed at a suitable height. Optimum coverage is obtained when the loop is offset slightly from the listening plane, and good results are often obtained by fitting the wire around the listening area at skirting height. Best results are usually obtained with a single turn loop and an appropriately powered amplifier. Multi-turn loops do increase the field strength, but the frequency response is reduced. The cabling route, though essential to provide coverage within the listening area, can be fixed at high or low level without diminishing the quality too greatly. Indeed in many applications a copper tape is fitted to the floor, under the carpet, and provides an exceptionally discrete installation.

Whilst a room may be deemed suitable for an inductive loop, we would strongly recommend a site survey first. Mains wiring, fluorescent lighting, steel structures and other building problems may decrease the performance of the system.

KEL SOUND AND VISION:

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E: sales@kelsoundandvision.com