Voices, Curse of Naxxramas, and more

Jalamenos asked:

Has there been any word from Blizzard about putting npc voices in a separate volume slider than the effects volume? As it is right now I can't hear most of what the bosses are saying world of warcraft gold without being deafened by all the sounds of us killing it. Feels like this is something they should have added a while ago especially since more and more of the game is getting voice cast.