His concept is for a headset that works off bone conduction technology. That means that rather than blasting out sound from a couple of speakers, the headset resonates the user's skull, which is picked up by the cochlea and interpreted as sound. It also keeps your ears free, so not only will you be able to hear external sounds (like traffic, for example), but you also won't be doing any damage to your hearing by having your earphones up too loud.
The Aura would use Bluetooth technology to transmit sound into your skull, and includes four speakers so you can really crank up that vibration. It's also powered by infrared solar power, so charging it should be cheap if it ever comes makes it to market.