Walter Tetley June 2 1915 September 4 1975 was an American voice actor specializing in child impersonation during radios classic era with regular roles on The Great Gildersleeve and The Phil HarrisAlice Faye Show as well as continuing as a voiceover artist in animated cartoons commercials and spokenword record albums He is perhaps best known as the voice of Sherman in the Jay WardBill Scott Mr Peabody TV cartoons Walter Tetleys perennially adolescent voice was the result of a medical condition which arrested his development preventing his voice from breaking into maturity as well as preventing his further physical growth In 1971 Tetley was seriously injured in a motorcycle accident and used a wheelchair for the rest of his life He died in 1975 at age 60 having never fully recovered from his injuries biography excerpted from Wikipedia