Nic Wallenberg has created something called The Human Speaker. It’s a special collar attached to two wires at the front that makes your throat produce a sound without you doing anything more than opening your mouth. The collar transmits vibrations directly to the upper throat (bypassing the vocal cords altogether) and generates a surreal note that can be modulated by the wearer into different sounds, much as one would do when talking or singing. The system is only able to generate two notes at a time, so several people have to wear a different collar in order to produce a more complex arrangement. Or they can be composited together as they have in the video below.
It’s a strange effect, and The Human Speaker doesn’t seem to have any commercial applications or ambitions at the moment. It’s still worth taking a look, if only for the novelty of it.