THE sensation of subjective tinnitus, its timbre and intensity can be extremely varied. Depending on the nature of the basic disease, it is sometimes even observed not to cause significant difficulty, while in other cases it is intense and troublesome. Since the time that Lempert,1 in 1946, advanced the original theory, according to which subjective tinnitus can arise as a result of pathological changes in the tympanic plexus, interest in the neurogenic origin of tinnitus has significantly increased. A series of facts previously unknown about the anatomical structure of the tympanic plexus was established by the investigations of Kruchinina,2 Lebedeva,3 Rosen,4 and Frenckner.5 The branches of the tympanic plexus do not always lie exposed under the mucoperiosteum. Sometimes its major branches pass in bony canals. It was established that two branches are always revealed in the tympanic plexus, n. cochlearis and n. vestibularis, which are