The ones we've got (from Tchibo) you have the head phones and then a piece that you plug into the relevant output (tv, radio, etc). My partner has two as he used to have his tv too loud and I listen to other things in another room. It's excellent one is recharging while he wears the other.
they work like this,
with the headphones comes an infa red transmitter
witch plugs into the headphone socket of the source
you wish to listen to..
ray.