"Alcmaeon was, says [J.] Wachtler, the first who attempted to explain the phenomenon of sound and our perception of it by reference to the structure of the ear itself. Empedocles to some extent follows or agrees with him. ...Empedocles teaches that hearing is caused by the impact of the air-wave against the cartilage which is suspended within the ear, oscillating as it is struck, like a gong."