Cone of Silence - Espionage device on the spy spoof GET SMART/NBC/CBS/1965-70. The Cone of Silence was used rarely by the Chief of CONTROL (Ed Platt), while bumbling secret agent Maxwell Smart (Don Adams) always insisted on private conferences. Debuting on episode No. 10 "Mr. Big," the Cone consisted of a large Plexiglass dome that dropped over two persons in need of communication.

The subsequent echo and shouting necessitated to communicate, nullified the effectiveness of the silly gadget. It's never really worked since it was purchased from a discount warehouse. Professor Cone invented the Cone of Silence.

The Closet of Silence and the Secret Word File were used as a backup to the Cone of Silence. The Secret Word file was a file of papers with words on them that were pulled out and flashed in front of the person with whom someone wanted to communicate. This procedure was done inside the Cone of Silence.

Years later on the short-lived revival GET SMART/FOX/1995 the Cone of Silence broke down (It was turned into a fish tank) and was replaced by the Booth of Silence that bounced sound waves up to a satellite which then returned a descrambled signal to the other person in the booth.

The ABC movie Get Smart Again! (1988) introduced "The Hall of Hush," a room insulated with noise mufflers that converted the spoken word into printed words that floated in the air

TRIVIA NOTE: On the sci-fi series CAPTAIN VIDEO AND HIS VIDEO RANGERS/DUM/SYN/1949-56, the evil Dr. Pauli (Hal Conklin) had a device called the Barrier of Silence, a sound dampening field used so that he couldn't be heard.