[microsound] Body-wired headphones

[Kim Cascone <kim@xxxxxxxxxxxxxxxxx>]

Body-wired headphones

Sony's Tokyo research lab has found a way to connect headphones to  
portable music and video players without the need for fiddly wiring.  
They simply feed an audio signal straight through the listener's body.

Existing wireless headphones use Bluetooth radio, but this means  
pairing two devices beforehand and is prone to interference from  
other equipment. Another approach – infra-red – relies on line-of- 
sight, which is rarely practical.

The new system uses the listener's body as a capacitor that carries a  
tiny electrostatic charge. A music or video player sends a  
fluctuating signal to a conductive cloth pad – such as a wrist band –  
and this slightly charges the wearer's body. A pair of conductive ear  
pads in the headphones pick-up the signal and rapidly convert it back  
into sound.

Just a few millionths of an amp flow through the wearer's body, so  
there should be no nasty tingling effect. To convert the small charge  
into good quality audio, Sony uses a high frequency signal, which is  
digitally switched to carry data at 48 kilobytes per second. This is  
enough to deliver good quality, body-rocking stereo, the company says.

Read the full body-wired headphones patent application.

http://tinyurl.com/y88h33