I have been noticing a ringing noise coming from under the car, it is more obvious when backing out of my garage, the sound bounces off the wall, it only happens when moving the car from a dead stop for an instant not while driving. It sound like something is vibrating, like gingle bells but very faint.

 

 

Well if you dont have it fixed by next Christmas I am sure someone will let you drive backwards through the Christmas day parade

jk.
Sounds odd, have you jacked up the car and looked over everything? Maybe have a friend or yourself back up the car while the other stands outside and tries to pin point the area.