IS PERILYMPHATIC PRESSURE ALTERED IN TINNITUS

Tinnitus is characterized by the continuous or intermittent auditory p erception of various sounds (buzzing, whistling, etc.) in the absence of any external stimulus. Perilymphatic hyperpressure is one of the nu merous mechanisms which could hypothetically be involved in tinnitus g eneration. In the present experiment, perilymphatic pressure was measu red indirectly using the tympanic membrane displacement technique. Twe nty-five tinnitus patients were investigated at 10, 15 and 20 dB above the acoustic reflex threshold with ipsilateral stimulation. The varia bles Vi (inward tympanic displacement), Vm (mean tympanic displacement ) and their variations according to stimulus level were compared betwe en tinnitus sufferers and age-matched or hearing-matched controls. Tym panic displacement was measured in sitting and supine positions so as to evaluate cochlear aqueduct patency. No systematic changes in respon se occurred in tinnitus patients, except at a high stimulation level, perhaps due to hearing impairment.