Maybe it’s like how I can close off my nose by flexing some muscle up there and not have to smell anything.
Very, very advantageous.
Just seen this thread resurrected by Salvador. While I have no knowledge of his or the OP’s condition, I can identify with Tyrphanax’s special power as quoted above. None of my family or friends are able to close off their nose like this; in fact, I don’t think I’ve ever come across anyone else who can until now… My friends think I’m making it up.