If the player killed the announcer during the Dunwall Tower mission, he will be replaced by a female announcer who will be heard through the rest of the game.
It's possible, but very difficult, to get through the entire game without killing a single enemy or person in general.
Voice actor Brad Dourif who plays Piero also plays Chucky the killer doll
The water lock featured in the Tower fills up in mere seconds. Real water locks can take many minutes to fill, but this fact has been bypassed due to artistic license.