'The Dark Knight': Bale's Voice Too Much

Why does Christian Bale's Batman talk like the offspring of Clint Eastwood and a grizzly bear?

As Bruce Wayne, his voice is as smooth as his finely pressed suits. But once he puts the cape on, the transformation of his vocal chords is just as dramatic as his costume change.

Particularly when his rage boils over, Bale's Batman growls in an almost beastly fashion, reflecting how close he teeters between do-gooder and vengeance-crazed crusader.

Though much of the voice effect is Bale's own doing, under the guidance of director Christopher Nolan and supervising sound editor Richard King, the frequency of his Batman voice was modulated to exaggerate the effect.