Hang on. By chance last night I watched a movie where I think they may have used the technique. Face Off, with Nicolas Cage and John Travolta. Anyway, for those who haven't seen it, two people switch faces and voices, but there are parts when they haven't yet traded voice, but have each others face. In these parts, when one of the actors speaks, they have the other's voice, and it works really well. It's definately not the actors themselves mimicing the voice. Watch the movie if you haven't seen it and you'll understand what I'm talking about. It's actually a good movie, too, apart from being a little farfetched.
When I set out from the boy's attic window, my head was so full of competing plans and complex strategems that I didn't look where I was going and flew straight into a chimney.
Something symbolic in that. It's what fake freedom does for you.