A device (invented by and named after Professor Cone) from 60's show GetSmart that allowed two people to converse in private.  Coincidentally its shape did vaguely resemble a cone.

http://content.answers.com/main/content/wp/en/1/14/Coneofsilence.jpg

http://www.answers.com/topic/cone-of-silence

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I don't know, it looks like a collection of hemi-spheres and cylinders to me.  I suppose the cylinders are a form of degenerate cone, but cylinder is a more specific and appropriate classification.  -- ChrisHines

I used to watch the show regularly as a kid (in syndication; I'm nowhere near that old) and as I recall there were two different versions of the CoS: one actually conical, and the other collection-of-hemispheres-and-cylinders that you saw. I presume that the change was made partway through the series; maybe the writers decided that it was funnier if the CoS were not actually conical. Or maybe it started out non-conical and they decided the irony was lost on the audience. Who knows (''not I''). -- KarlKnechtel

''check the lead sentence - Prof. Cone was the inventor''