There are several statuses in the game that affect speech. I would like to propose adding 'in pain' as one of them. That way, like the other speech affecting statuses, you don't need to intentionally affect your speech, but rather the game will alter it for you. This obviously wouldn't cover every situation, but would have your back in the event that you're in a fast paced scene in which your character takes a shotgun blast, and you as a player simply...slip.