Today on December 17th 1936 Edgar Bergen introduced his dummy Charlie McCarthy to radio. It was on the variety show The Rudy Vallee show. For a good writeup on the show and Edgar Bergen go here http://www.oldradioshows.org/2013/12/charlie-mccarthy-premiers-on-royal-gelatin-hour/
The article does ask the question why would you have a ventriloquist on a radio show - how would you know if his lips were moving?
Before WBOC-TV started up in this area, about 1952, the "Charlie McCarthy" Shows on radio were one of my brother and I favorite show, along with "Our Miss Brookes," "Jack Bennie," "Amos N Andy," and "The Lone Ranger."