There are two types of wireless technologies that are used with headphones, Infrared (IR) and Radio Frequency (RF):
- Infrared (IR)
This technology requires a line of sight with the signal transmitter. IR headphones were supplied wiith some models. Additional headphones can be used at the same time provided that they are designed to receive IR signals.
- Radio Frequency (RF)
This technology converts a line level audio signal to a radio frequency and broadcasts the signal to the headphones. Line of sight is not required with these headphone styles. Additional headphones can be used at the same time provided that they are designed to receive the same RF signals.