Little is known about Ralph, other than that he's got a killer mullet, he's from Michigan and he can throat whistle with the best of 'em.  In the clip below from WXYZ's Kelly & Company Show in 1984, he explains his unique "talent".  He tells Kelly (presumably, it's Kelly) that he simply puts his tongue on the roof of his mouth and "just cranks on it".  Right.  

Kelly then asks 2 or 3 follow-up questions, which appears to be 2 to 3 questions too many, before handing things off to Ralph for his big performance.