I saw in the 1.1.2 changelog that "Ravens now make proper sounds. Quothing is involved." I've started a new character today and ravens on floor 1 were correctly making the new sounds (which are great by the way), but any ravens past floor 1 still make the old pre-1.1.2 sounds (same sfx as Wight I think?)
Intended, but open to question: I kept the Wight sounds for the other ravens because they're magically evil.