Think of infrared emitters as a beam of invisible light.  Emitters are available in different sizes, depending on the area of coverage and number of channels required.  In most applications, multiple emitters are used to ensure even coverage of the light, so users do not experience blind spots.

1.  Input to an infrared system can come from a microphone, sound system or another audio source.  The presenter speaks to the participants using an existing microphone and the audio input produces an electrical signal which contains the audio information.

2.  The electrical signal is then fed to the infrared modulator, which prepares the signal for infrared transmission.  The processed signal is then fed to the emitter, which produces the invisible infrared light and radiates it into the room.

3. Infrared receivers convert the infrared light back to audio. Participants requiring hearing assistance each use an infrared receiver to listen to the presenter.