- here is your Xmas story! Are body-wired headphones ahead of the e-
Scott jacket? Merry Xmas!
Invention: Body-wired headphones
15:40 27 November 2006
NewScientist.com news service
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
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.