Hess was best known as the German voice of the burly Italian actor Bud Spencer in many Westerns, action films, and comedies. He dubbed John Rhys-Davies as both Gimli and Treebeard in The Lord of the Rings films and took over from Klaus Höhne as the voice of Dumbledore in the Harry Potter movies. He also dubbed Raul Julia in The Addams Family, Lon Chaney, Jr. as The Wolfman, Michael McShane as Friar Tuck in Robin Hood: Prine of Thieves, Jon Polito in The Man Who Wasn't There, and James Earl Jones in What the Deaf Man Heard.