Humming noise from my surround sound Bravia 1080...

Question

I have a loud humm that happens when I turn on my tv - it is constant and increases if I turn up the volume.  Is it somehow related to the Wii?  It seemed to start this when we hooked that up into the system.

Also is it perhaps some setting on the remote?  It seems to me that it was intermittent for a while .