I just got a new Panasonic plasma. If I run the cable TV right into the back of the TV---sound is fine. If I run cable TV thru my Tivo or Digital cable box and then into the TV - I am getting a humming noise in the background of the audio. Very annoying and frustrating...have tried regular and S video cables...
problem is solved. the issue was a wall mounted electric outlet splitter. once i took that off and hooked everything up to a power strip the hume went away