... determine speech by analysing the movement of a user’s lips as they speak into a camera. These lip movements are known as visemes and are the visual equival

... determine speech by analysing the movement of a user’s lips as they speak into a camera. These lip movements are known as visemes and are the visual equivalent of a phoneme or unit of sound in spoken language. Bumped into this while researching something else. Amazing. Also slightly creepy, in the same way it's possible to eavesdrop on conversations in a room by laser detection of vibrations in window glass. https://en.wikipedia.org/wiki/Laser_microphone https://en.wikipedia.org/wiki/Laser_microphone ... which evolved from tech originally by Leon Theremin. Cool.