In 1855, a young professor of anatomy and physiology in the University of Bonn (he was then only 34 years old) wrote a letter to a friend, who was also an academic colleague: indeed, he taught physiology in the University of Berlin. In that letter, the sender expressed his intention to devote himself to the study of acoustics. One year after, his scientific project was already well defined, and he could proudly write: "I have gradually accumulated a considerable amount of material for the reform of physiological acoustics."¹