In the Spanish (EU) version of the game the Orc Shaman mostly speaks in english and some quotes are in spanish. And a lot of more units have the same problem, though in varying degrees.
Refer to this post: Blizzard Forums
I think it may be a problem with many other wc3 versions. At least russian shaman has English quotes as well.
Do you run russian version of the game? Could you check Furion’s voice as well. As I’m aware it’s broken too.