  People feel emotions when listening to music. However, emotions are not
tangible objects that can be exploited in the music composition process as they
are difficult to capture and quantify in algorithms. We present a novel musical
interface, Mugeetion, designed to capture occurring instances of emotional
states from users' facial gestures and relay that data to associated musical
features. Mugeetion can translate qualitative data of emotional states into
quantitative data, which can be utilized in the sound generation process. We
also presented and tested this work in the exhibition of sound installation,
Hearing Seascape, using the audiences' facial expressions. Audiences heard
changes in the background sound based on their emotional state. The process
contributes multiple research areas, such as gesture tracking systems,
emotion-sound modeling, and the connection between sound and facial gesture.
