The 'Soundchair' Uses Your Body as a Speaker

Picture settling in to watch a TEDTalk years from now and being the speaker—not "speaker" as in the one wearing the little mic, and running the tasteful Powerpoint. But rather, you are the medium through which you hear the mic-wearer.

The source of the sound, in this scenario, is your body in your chair. It's a prime example of hearable technology, and is perhaps best illustrated by  US Patent 8,684,457 under the title "Chair and Multimedia Player Comprising Sound Transmission Apparatus Performing Human Body Communications."

Sung-Em Kim is the lead inventor on both the soundchair and the techn that makes it go, and has been working for years on the field of "human body communication," which, surprisingly, has nothing to do with waving or the  Dikembe Mutumbo finger waggle.

As the  2012 patent that comprises the soundchair explains, "human body communication is where a signal is transmitted by using a human body rather than by using a wire. In human body communication, the electric signal is transmitted through the human body without using electric wires since the human body conducts electricity."

Human body communication as a field has already attracted interest from some heavy hitters. Sony is working on  using the human body as a conductor to replace the wire on headphones. Disney Research is working on replacing the headphones themselves, by transmitting sound through a fingertip touching near the ear.

The working soundchair, as described in the patent, allows the user to hear the multimedia player through contact with the chair itself. There is no receiver up by the ears that converts the electric signal into an audible one; instead, two high-frequency signals—one a composite, and one an out-of-phase demodulation signal—that interfere with each other around the ear in a way that allows the audible signal to be heard by the sitter.

There's obviously a lot of challenges here. Compared to human bodies, headphones are a lot more standard, and it looks like the signals would have to be calibrated specifically to the user's body in order to make the signals audible around the ear specifically. There's also the matter of many of us using headphones specifically because they deaden outside noise by occupying our ear canals, which the soundchair leaves open.

And before this ends up going to market, it remains to be seen how comfortable people will be with electricity shooting through their bodies in lieu of cables. Although, if wearables like Google Glass—something that affixes to your face and has come to symbolize a class divide—is any indication, a capable marketing department should have no problem overcoming that.