In The Great Gabbo (1929) Erich Von Stroheim plays an unlikable & ruthless ventriloquist of unusual talent, a delusional star who gradually loses his way & discovers the only way he can communicate with other people is through his dummy Otto. He is slowly driven insane by his relationship to the haughty & sharp-tongued Otto & loses Mary, the only one he loves in the process. In this sequence he yodels with a shawl stuffed into his mouth, making this one of the most unusual yodels ever. This film is featured in the chapter "The Yodel That Ate Celluloid" in YODEL IN HIFI uwpress.wisc.edu/books/4594.htm