Audio Systems: no a/v output, x box 360, game chair

Question
  I just bought a x-rocker game chair but in order for it to work it needs a audio out and my tv has none.  Is there something that I can buy that will link my x-box 360 and my TV so I can enjoy the chair?

Answer
If the TV does not have an audio out, then the only way this can work is to get the audio feed from the Xbox first then pass it along to the TV.  Does the chair have a "pass thru"?  In otherwords can you connect the Xbox to the chair then run the audio from the chair to the TV?
Dan