I have to agree with others here who found Bale's Batman voice annoying. What the heck was THAT all about?
Well think about it. Wouldn't someone in that whole city recognize eventually how both The Batman and Wayne have a similar voice? Hell this possibility is compounded by advances in technological, specifically the recording kind.
Plus, I think it's supposed to be an inhuman voice, like what kind of a person orders a pizza over the phone with it?