More Details Needed

More details would certainly be helpful.

You could plug in the headphones to the source device if available (e.g. cable box, BD/DVD player).

If it's just basic cable (analog service), options are few. If you have an old VCR that has RCA audio out, you could try that. The downside is you would need to use this as the tuner for your TV.

For over-the-air service, you might be looking at a little more expensive or complicated solution.