After watching Episode III there was something about General Grievous that I was curious about. In the scene where we first see the General, on the Trade Federation Ship, he has these 2 metal flaps on each side of his head. I know they must have a purpose because we see them moving when he first enters. But what their purpose is, I don't know. I'm thinking they're some kind of sensors for hearing, but I can't be certain. They may also be used to help him breath. If anyone has any opinions or info on this please share it.