Can't deny that I do. I wont shout and scream or anything, but I will usually get snarky with some characters, especially enemies who proclaim I'm about to die. So yeah.
The only time I'm liable to swear is if I get snuck up on. In ME3 multiplayer for example, I turn around and there's a banshee behind me, I will simply go 'oh fuck!' before high tailing it the fuck out of there.
Probably a god job I don't have a mic then...