No - it will not be the aerial - the sound and picture signal are all mixed up together and come into the tuner down a single wire along with millions of other signals - the tuner selects the signals you want to watch and the TV's circuitry separates sound from vision.
Your TV needs to be seen by a TV doctor.
If you have another TV connect it to the Aerial and see the result.
Good luck...
Peccavi, March 2013
