Nic Wallenberg’s Human Speaker collar turns one’s mouth into a speaker. Our throats produce sound by one’s vocal chords reacting to air from the lungs, and the resulting sounds then being amplified by the mouth. Wallenberg’s device bypasses the vocal chords and transmits vibrations directly into the upper throat. Wearers can play with the music they emit by moving their lips and mouth. Each collar can produce up to two music notes at a time, so the more people using the collars together the more complex the compositions can become.