Hearing Loop Systems

A new range of compact free-standing, constant current, phase-shifting hearing loop amplifiers, from SigNET.

SigNET's Outreach Plate audio input extension system comprises a range of wall, ceiling and desk mountable single gang audio input plates specifically designed to increase the audio input capability of an induction loop system. Covering the most common variants of audio connector, they work by mixing the signals from various audio input sources into one balanced line level input which can be fed into the line input of a compatible amplifier.

Mountable on 25mm back boxes, each plate features a built-in mixer, pre-amp, input level control and balanced output. The fact they can be installed at the most convenient point on an installation overcomes the need for long and potentially hazardous microphone/audio leads.

Typically, up to 10 Outreach plates (any mix) can be daisy-chained to one balanced line level input with cable lengths of up to 100m easily achievable using standard two-pair audio cable with no recognisable degradation of audio signal quality.

Each outreach plate requires four wires, two balanced line (A +, A –), one ground (0V) and one power connection (12-32 V DC regulated). Click on the thumbnails below left for typical wiring schematics.

ble c/w Schuko plug adaptors, black, 7.5A (add /SH to the UK part nos)

A microphone is perhaps the most important link in an audio chain.

As the connection between the sound source and the sound system, it must interact efficiently with both.

Choosing this link successfully requires knowledge of the sound source, the sound system (including the room acoustics), microphones and the actual application.

A number of microphones are available from SigNET for use with its induction loop systems (see our Microphone Selection Guide below).

SigNET recommends all its induction loop systems are tested using a ‘Fosmeter Pro’ Induction Loop Test Kit (FPROK1).

Designed to simplify the setup of an induction loop system to the latest version of BS EN 60118-4 (Magnetic field strength in audio-frequency induction loops for hearing aid purposes), the kit includes an FPRO Fosmeter Pro induction loop tester c/w intuitive display and simple to follow test menus, a calibrated signal generator c/w pre-loaded test tones and a set of headphones.

As well as checking the magnetic field strength of an induction loop system, it also measures background noise, frequency response, metal compensation AND allows you to listen to the loop signal.

The tester and signal generator are each powered by a 9V PP3 battery and both are supplied in protective canvas carrying cases.

SigNet can supply two types of Induction Loop Cable:

Copper foil tape is typically used for floor loops under light duty carpets. Protective tape is also required to hold the cable down and reduce the likelihood of damage. Copper foil tape should be connected to the loop amplifier using solid 0r 1A ‘choc’ block.

Note: The chemical elements of some self-leveling floor compounds can react with the pastic covering of copper foil tape. If installing the loop under such a compound, we recommend you check compatibility by testing a small piece of tape with the compound and check for adverse reactions.