The human face is full with muscles and able to express at least 200 different emotions which can be interpreted by almost every people. Electric diodes are often take to stimulate the muscles to get them active, example for growing in case of an injury.
Look and listen to the video below what Daito Manabe from Japan did with with some of those electric diodes. He made his face working as an equalizer by analyzing frequencies of music.
Inspired by: FearBlog.
Freaky *lol*