Bale was going for the same idea that Kevin Conroy did with Batman: TAS, that Bruce Wayne and Batman would have different voice pitches. Obviously on one hand to aid in the disguise and PR ruse regarding Mr. Wayne, but also it pushes the thematic idea that they are two seperate characters. (Is Batman what Wayne really is and "Bruce Wayne" is his disguise?)





See? Subtle brilliantly-performed differences in the pitch, obviously the same voice actor but it gives a distinct character differential, and without being distracting or becoming a subject of intense public mockery. That's why he gets my vote for the greatest Batman actor.

I suppose Bale and Nolan wanted to make their Batman have a growl, like to build into the idea that he's intimidating people. But I don't know, a dude in a bat costume kicking your ass and dangling you off a rooftop would be enough to share me into cooperating, IMO. Honestly the only conceptual misstep Nolan has taken, if you don't count the useless prop that is Rachel Dawes, though to be fair she had a thematic importance in THE DARK KNIGHT. But she is a dull drag in BEGINS.