Temporal bones will be acquired from human subjects who had experienced disorders of the peripheral auditory and/or vestibular system, middle ear, bony labyrinth, or facial nerve. The specimens will derive predominantly from the morgues of the Harvard teaching hospitals, the National Temporal Bone Bank Program), and from foreign countries (Costa Rica, Chile, and Switzerland). The temporal bones will be prepared for light microscopic study by the method of fixation, decalcification, embedding in celloidin, serial sectioning, staining, and mounting. The pathological changes will be identified and quantified as to severity and spatial distribution and correlations made of the temporal bone findings with clinical data. General medical and otologic histories and autopsy findings will be available on all subjects, and most of them will have had detailed audiometric and/or vestibular function tests. It can be anticipated that these studies will further our knowledge of the pathology of deafness, vertigo, and facial palsy, and will lead to more rational therapeutic approaches to otologic disease.