A human input system is described herein that provides an interaction modality that utilizes the human body as an antenna to receive electromagnetic noise that exists in various environments. By observing the properties of the noise picked up by the body, the system can infer human input on and around existing surfaces and objects. Home power lines have been shown to be a relatively good transmitting antenna that creates a particularly noisy environment. The human input system leverages the body as a receiving antenna and electromagnetic noise modulation for gestural interaction. It is possible to robustly recognize touched locations on an uninstrumented home wall using no specialized sensors. The receiving device for which the human body is the antenna can be built into common, widely available electronics, such as mobile phones or other devices the user is likely to commonly carry.