During the 1940s - 50s, Harry Hemsley was another ventriloquist with a radio programme about his family. He incredibly voiced all his imaginary children himself. The family consisted of Johnny, Elsie, Winnie, and the infant baby Horace. Each had a very distinctive voice. Following a conversation with his imaginary children, the baby would come out with some gibberish. Dad would then ask "What did Horace say, Winnie? She would translate - and we would all burst into laughter. We must have been mad.
In a later short series on TV, Harry hid his mouth behind a book he was reading. Of course no children were ever seen. Just him - from the eyes up.