How do infrared hearing systems work?
1 The input to an infrared system can be from a microphone, a sound system or any other audio source. They each produce an electrical signal which contains the audio information.
2 This signal is fed to the modulator which prepares the audio signal for the subsequent infrared (IR) transmission.
3 This processed electrical signal is then fed to the radiator. The radiator light emitting diodes produce the (invisible) infrared light and radiate it into the room.
4 Wireless receivers are used to convert the infrared light signal back into an electrical signal and then into an audio signal again (or a personal induction loop if used by a hearing aid wearer). There is no limit to the number of receivers that can be used on a system.
Most infrared hearing systems are single channel and use a radiator with an integrated modulator.
The easiest way to regard infrared radiators is to think of them as floodlights of invisible light. Radiators are available in different sizes depending on the area of coverage and the number of channels required. In most applications multiple radiators are used to ensure an even coverage of the light so the user doesn’t experience blind spots. With the exception of the smallest model, radiators are available in either a black or white finish.