Our Ella is going on 11 months and she has never yodeled. Actually, one time when she was unhappy in her crate I caught her making a yodel from outside our front door. We have tried to encourage her by yodeling ourselves and by playing her videos on youtube. We only get the occasional low grrrr when we come home. So we are accepting the fact that she is not a yodeler. But we are really appreciating our mostly silent barkless dog. So peaceful.