Hearing

Abstract

In 1561 an Italian anatomist reported that, in studying the bones of the skull, he had found that the temporal bone contained a system of cavities and tunnels. The most conspicuous part of this structure was a fluid-filled tube, about 3 cm long, that coiled in the form of a snail; hence it was called the cochlea. The functional significance of the tube remained a mystery up to the middle of the nineteenth century. At this time another Italian anatomist, Corti, reported that branches of the eighth cranial nerve, the auditory nerve, entered the cochlea and terminated in close contact with cells which on their apical surface carried hair-like processes. Corti’s discovery led to a host of studies on the function of this organ, which was subsequently termed the organ of Corti. The most important of the many papers published in the following years was a monograph entitled The Theory of Sound Perception by Helmholtz, who suggested that the basilar membrane of the organ of Corti is composed of tight strings and functions as a tuned resonator like the strings of a harp.