There are many ways to take an electrical audio signal and turn it into something you can hear. Moving coil speakers, plasma domes, electrostatic speakers, piezo horns, the list goes on. Last week at the Electromagnetic Field festival in the UK, we encountered another we hadn’t experienced directly before. Bite on a brass rod (sheathed in a drinking straw for hygiene), hear music.
The TOG Skull Radio demo box
This was Skull Radio, a bone conduction speaker courtesy of [Tdr], one of our friends fromTOG hackerspace in Dublin, and its simplicity hid a rather surprising performance. A small DC motor has its shaft connected to a piece of rod, and a small audio power amplifier drives the motor. Nothing is audible until you bite on the rod, and then you can hear the music. The bones of your skull are conducting it directly to your inner ear, without an airborne sound wave in sight.
Read the full story over on their website. https://hackaday.com/2016/08/17/bone-conduction-skull-radio/#comment-3139160