Infrared hearing system have many advantages over induction loop systems-
-Infrared light cannot penetrate walls or ceilings so overspill does not occur, unlike perimeter induction loop systems. This allows systems to be used in adjacent rooms and in rooms where confidential meeting take place e.g. Court rooms, boardrooms, interview rooms, etc
-There is no loop wire to run around the perimeter so it is easier to install in rooms with multi-levels e.g. Theatres, or wide areas e.g. Exhibition halls.
-As infrared light carries the signal there are no losses due to the amount of steel in the construction of the room which can affect the signal and frequency response of induction loop systems. Systems can also be used (with stethoset receivers) in environments with high background magnetic interference.
-Portable infrared hearing systems are quicker to set up than portable induction loop systems as there is no wire antenna to install around the perimeter of the room. There are also reduced Health and Safety issues associated with trailing wires.
-Multichannel systems are available.
For multichannel infrared systems an external modulator is installed which feeds the radiators. Typical examples where twin channel infrared systems are used are-
-In a cinema, a twin channel infrared system would be used to feed the film soundtrack for hearing impaired people on one channel, and an audio description to assist visually impaired people on the other channel. Signs and an announcement before each film inform customers that the system is available. Receivers are then issued to the customers who request to use the system.
-In a council chamber or conference room where bilingual meetings take place and a hearing support system is required (to comply with the Disability Discrimination Act). In this case one channel of the system would be fed by an interpreter’s microphone, and the another channel fed from the floor language via microphones (or a sound system).
-Twin channel receivers are used by the delegates to listen to either the translated or the floor language.
-Twin channel systems can also be used for stereo sound applications.
If more than 2 channels are needed then a narrow band infrared system can be installed allowing up to 32 channels. These are used for simultaneous interpretation at international meetings.