I think I assume that people's voices will be low. I grew up around a lot of low-voiced, deep-voiced people. It's possibly what I'm used to. (For years I assumed Peter David's voice was fairly low, then I finally saw him in a video clip discussing The Dark Tower. Oh.)
And supposedly Abraham Lincoln had a high, reedy voice. I still have trouble reconciling that, though (save the invention of a time machine) I'll never know exactly how he sounded.
History may be told with the wrong tone! It's often told with the wrong accent, too, but that's a whole other movie-related talk (like this morning's other entry)...