Interesting. I've heard that there are TV sets available now with Bluetooth audio capabilities (that is, for use with Bluetooth headsets). I don't know whether you can have headsets "tuned" to individual TV sets, though (but this would be possible technically, of course). Otherwise, why not get a single massive plasma TV (only joking)?
The other way to look at the problem, I guess, would be to think about providing isolation at the stereo socket end (an isolation amplifier). Something for you to have a go at, perhaps? But as you obviously know the exact requirement, with that in mind maybe you could spend a fruitful ten minutes or so on Google!
Can't that screening be earthed, by the way?
