HISTORICAL BACKGROUND Vibratory sensation, both the exploration of its nature and its clinical interpretation, has intrigued physiologists, neurologists, otologists and psychologists for the past one hundred years. Johannes Mueller,1in 1830, mentioned it briefly in his textbook of physiology, to adduce further evidence for his doctrine of the "specific energy of nerves." The first to analyze this sensation was Weber,2who, in his admirable monograph on sensation (1842), wrote in the chapter on the relationship of the sense of feeling to other senses: In the rapidly successive impulses falling on sensory end organs one has a transition from feeling to hearing. By their confluence, these impulses make up a sensation, which can be altered by the length of the intervals between them. These vibrations are felt as a movement, which is taken up by the auditory apparatus as a tone. It is subject to manifold modifications, such as,