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A lot of the wireless headphones that I've seen don't actually plug into a headphone jack. The transmitter section plugs into either a set of analog RCA jacks or a digital audio jack, either of which is generally located on the back of the receiver or HTIB main unit. The problem with a lot of the HTIB systems is that they have pretty limited connectivity. Unfortunately, your Sony HT-SS2300 (based on their website) doesn't have any outputs except for the HDMI output. However, your TV has both analog and digital outputs, so you could run the headphones off of the TV pretty easily. A potential downside is that the TV would need to be on to do it (even if you were just listening to music).
Adam
EDIT: Even if the headphones use a headphone jack, you can get a very inexpensive adapter cable to convert that to plug into the RCA analog audio jacks. Let me find one for you. Just a second.