The perpetually broken device on the show 1960s show
Get Smart. Maxwell Smart would always demand that the Cone of Silence must be used for what ever purpose he needed. Quite often he felt that they must have meetings in secret and would not do anything until it was lowered or some security measure used.
The cone would be two bubbles connected with a tube of plastic; it was made so both people could hear a conversation with out anyone else listening in, of course like most things on Get Smart, it never worked.
Some of the many problems relating to it:
The cone would work perfectly except during the conversation it would move up and down so that Maxwell Smart and the Chief would have to follow it. It kept moving to the point where it would come down and break the desk in half.
The cone would be used in addition to the use of cards to show information, the cards would be come so tedious that the chief would just give up as well as Larabee, the chief's assistant, would also have a set to tell him about calls.
The portable version of the cone would get stuck so one could not get out of it at all, one would have to walk back to Control Headquarters stuck in the cone of silence or shatter the cone if one couldn't figure a way to open it.
Often the cone would have people shouting secret information so loud that the people outside the cone could hear it better then the people inside the cone of silence.
To be continued?