Headphones with little speakers on the outside but none on the inside. The outside speakers would only reproduce the high/mid-high frequencies so that it seems like you're blowing your eardrums out.
This could be useful in conversation avoidance or sneaky eavesdropping.-- Fishead, Sep 12 2000 Trigger Happy TV http://www.triggerhappytv.com/frames.htmUses the headphones to confuse and provoke passers-by [Tlogmer, Oct 04 2004, last modified Oct 21 2004] Add an antenna, so you don't have to carry around a portable player to plug it into.-- absterge, Sep 12 2000 saw this in MAD magazine once-- nano_mars, Mar 16 2001 They could be noise-cancelling, too --- either cancelling their own noise (for better eavesdropping) or cancelling exterior noise (for better pretending-not-to-be-able-to-hear-people).-- wiml, Mar 19 2001 Baked, on the british series "Trigger-Happy TV". The speakers are pretty big, though.-- Tlogmer, Jan 23 2003 When I posted this idea it got fishboned and [m-f-d]'d for redundancy.-- snarfyguy, Jan 23 2003 random, halfbakery