I might have to go check out DoW2 again! I honestly don't remember the sound from there.
For me it's like a low throb, not dis-similar to ONE OR TWO dubstep beats... not the whole bloody kaboodle, mind, that'd be horrible.
So kind of a "waaooow-wuuuooaaab"...
Lances for me are a much more high-pitched scream, like it's killing a thousand cats in its path. Sort of like Star Wars blasters, but longer and louder. "FWEEEEEEE!!"
(added)...this is a fun conversation, I've decided. Have an exalt for a good question.