If your hearing aid has a "T" position, AND you have an audio amp of some sort connected to the telly (such as a surround sound system), you can pretty easily make an induction coil ("loop") out of mains flex, to go on the floor under the sofa, so you can beam the sound straight into your hearing aid.
I set this up for a friend and she's delighted with it, as husband and wife can both now listen to the telly at a mutually comfortable level and nobody need know the system is there. It's invisible under the sofa, with just one speaker-style cable going to it (routed round to the back so it's not obvious).
There are commercial versions of these, but I believe they're expensive. You need a small audio transformer (known as an "100V line transformer" in the trade), and a small plastic box to put it in (with a chocolate-block connector too, for the wiring-up) but they're all easily obtained, either from eBay, RS Components or Farnell/CPC (or Maplins if you have a bottomless wallet).
I can't honestly remember how I made J.'s one now, but I'm sure she'll let me look at it if you want the details. Doing it really tidily, with a plug-in cable (so it was easy to move about for hoovering), was something eye-stretching like about £35-40 in bits, tops. A really cheap amp will do the job, too* - it doesn't need to be posh, as there isn't much power used.
HTH,
E.
*It has to work properly though - something cast-off is fine, as long as it's not faulty.
