sound distorted on my tv
 

I have sky+ and my sound is permanently distorted, it is not the tv as I have tried a different tv and the same happens.
I have a cable thru to my bedroom and the sound is distorted their too.
If i put the sound on my sitting room tv to the right speaker it works ok, but not in the bedroom though. very confusing I know.
It has to be the sky+ box.
any ideas on why this is happening and how to fix it.