Labyrinthine Otosclerosis: Special Auditory Test Results

IN DETERMINING the etiology of hearing impairments, the otologist is at times confronted by the patient whose sensorineural hearing loss presents special problems in diagnosis. In many cases the history, the otologic examination, and the pure tone audiogram all fail to offer clear-cut indications of a particular pathology. Probably the most common procedure in such instances has been to describe the problem as a "sensorineural hearing loss of unknown etiology." Most if not all clinic files contain a large number of cases so described. It is my belief and that of the group with which I work that at least some of the hearing losses of the type the otologist is tempted to label "sensorineural, etiology unknown" are actually the result of otosclerotic foci deep to the oval and round windows.⁴That the otosclerotic process can and does invade the cochlear space and the internal auditory meatus has been