A real-time installation created with Touchdesigner and Kinect that communicates with people by catching their distance and movement, implementing the sonar principle. Sonar (sound navigation and ranging) is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels. In my project, I used people's movement as an active transmitter and receiver. By using the Kinect device, people's movement affected by the reaction from the machine in real-time. The machine responded by showing the viewers their generative visual reflection and played the sound that changed its volume according to their distance.