ProSound is an instrument that explains “Proxemics” theory by altering lights and audio to the audience. It is composed of a 3D priented enclosure, infrared proximity sensors, a LED, and Arduino. Its size is  4 inch (height)*3.5 inch (width) and it looks like a semitransparent bottle with three “eyes”. Proxemics introduces four types of interaction spaces: intimate space, personal space, social space and public space. In ProSound, we hope to detect three spaces: personal space, social space and public space. Through the central proximity sensor it can detect the distance between the user and the bottle, indicating what space the user is staying at. It will changes LED’s colours and the loudness of the sound according to the distance. In addition, when the user stay at the social space, which means the normal interaction space, ProSound records user’s speech and repeats it again and again. A piece of midi clip is playing when user interact with the bottle. The user is able to control the speech’s pitch and the interval of the midi clip by approaching the proximity sensors on both sides by hand. Our project is aimed to deliver the concept of “Interaction Space” through user’s interaction with ProSound. We hope users understand the principles of Proxemics in playing with ProSound and the magic things they can make with space.