Transhumanism, body modification or "bio-hacking" is the name given to the process of augmenting the human body with the help of technology. While it may not be widespread, there is a dedicated underground community seeking ways to improve on the general design of the human body in creative ways.
The latest step forward is the advent of "invisible headphones". Rich Lee, a self described body modification fan, has implanted magnets in his ear lobes. Combined with a coil mechanism which can be worn around the neck and under clothing, the magnets serve just as regular headphones would. Sound would be transmitted using bone conduction technology, which will be found on devices such as Google Glasses. The inspiration for the move came from a video posted on Instructables.
The "invisible headphones" can be used for other purposes than just playing music. Rich Lee, who is losing his eyesight, aims to connect his bio-hack to an ultrasonic range finder and make a bat-like echolocation system. The headphones will hum in varying degrees of loudness based on the distance of the objects.