The Sense of Hearing
Mr. John Marshall, in a Lecture on the special organs of the Sense of Hearing, describes the wonderful arrangements for the protection of these organs and their adaptation to their office; the examination of their relative duties, in distinguishing the kinds and intensities of the sounds of such exceeding variety, produced by inanimate nature, by animals, and by art (music). For the appreciation of the pitch and quality of sounds Mr. Marshall considers that we are indebted to the delicate fibrous structure of the cochlea; for the knowledge of the intensity of sound to the tympanum or drum, which, possessing the power of tension and relaxation, thus acts a protective part; while in our knowledge of the distance and direction of sound we are guided by the external parts of the ear and by our experience.