Headphones connected to some sort of music player which puts a minute voltage across the two earpieces and only plays music when the measured resistance across the earpieces is close to the pre-calibrated resistance of your head. So, when you take your headphones off, the music is paused.-- hippo, Jun 17 2005 Interestingly related patent http://www.patently...-heart-sensors.htmlThis patent talks about the identification of the user of an electronic device by looking at characteristics of their heartbeat, including through picking this up through conductors in headphones or earbuds. [hippo, Jun 28 2010] AKG K271 http://www.akg.com/...2,_language,EN.htmlHeadphones that turn off when you take them off. No, they don't pause the music. [Cedar Park, Jun 30 2010] This fails to take in to account the larger headed gentleman. Also, I often prefer to listen to music using one headphone, so that I can pay semi-attention to the world around me. How would that work?-- hidden truths, Jun 17 2005 //This fails to take in to account the larger headed gentleman.//Did you miss the bit where it says 'pre-calibrated'?-- angel, Jun 17 2005 Yes [angel]. Yes I did.-- hidden truths, Jun 17 2005 You could put two contacts on each 'phone and measure the resistance of the ear/side of head (depending on size of headphones). You'd need less power and wouldn't end up shoving it through your brain... unless that's the point?-- st3f, Jun 17 2005 [st3f] that might be a better idea actually-- hippo, Jun 17 2005 Schmoove [+].-- DocBrown, Jun 17 2005 hippo: all part of the same general idea. Halfbrainstorming.-- st3f, Jun 17 2005 Apart from the charm of micro-ECT, I don't understand how this improves on a simple pressure sensitive switch.-- mouseposture, Jun 28 2010 Wouldn't a pressure sensor be simpler?-- Alx_xlA, Jun 29 2010 Capacitance might work better.-- csea, Jun 30 2010 A simple microswitch does the trick for the AKG K271 heaphones. They turn off when you take them off your head. [link]-- Cedar Park, Jun 30 2010 random, halfbakery