ethel ....
tried my toshiba .... you could hear a pin drop ... no joy
however
sort of a variation on mattk's suggestion
do you remember posting a photo of a "mystery" cable you found that I said looked like a phono lead?
your new telly will have a bewildering number of connectors .... and there should be a couple of phono sockets ... for home theatre or whatever
if you cut the plugs from one end of the cable
and replace with
2.5MM STEREO FEMALE JACK
http://www.maplin.co.uk/Module.aspx?ModuleNo=1 143&criteria=2.5 socket to phono&doy=26m3
(like the second picture ... but replace the stereo plug with a socket).
you could then connect earphones to the output which shouldn't cut the speakers.
I can find every combination except this one on google .... but it's the sort of thing that anyone with a soldering iron could cobble together in minutes .... (perhaps your local tv repair shop??)
it should only cost a couple of quid .... you could nip down to currys and give it a go just to be certain