Herman von Helmholtz (1821-1894) can safely be called the father of modern acoustics. After his medical education he became fascinated by the physiological aspects of acoustics and optics. In 1858 he wrote a study about the sensory perception of sound and thus contributed considerably to the theory of music. He was the first to describe the function of the cilia in the ear, which he recognized as objects that resonate with certain tones. This resonator bank with 19 different resonators is a consequence of this study. To prove the presence or absence of a certain pure tone in a piece of music, a resonator is held close to the ear. If the resonator resonates, the tone in question is present.