This simple application shows the tonotopic organization of the human cochlea.
How the program works: the input from the microphone is divided into several frequency ranges. The amplitude of a given range is mapped to the region of cochlea that is responsible for the process of converting the energy. It is not 100% accurate, and boundary frequencies may spread to several regions. Like in living cochlea, pure tones excite not only one region but many, although one region is excited mostly.