How do I do that preparation [for film]? Just an immersion....

How do I do that preparation [for film]? Just an immersion. I have a musician's, I guess, ear for the sound of the voice but it's also important to me, in the case of [playing] someone who is controversial, to get the outlines of the character right because how they present themselves to the world has a great deal to do with how people feel about them.