Abstract
Hydrostatic pressure of the perilymph was changed by introducing a small catheter into the epidural space and changing the cerebrospinal fluid pressure in guinea pig and cat. Changes in hydrostatic pressure of the perilymph affected the cochlear potentials (CM. AP), but physiological pressure changes (+100 mm H2O) maked no hearing loss. High pressures (500 -1, 000 mm H2O) were required to produce sensorineural hearing loss (SNHL) that was greater for low frequencies and was reversible in short time experiment. Perilymph fistula was experimentally produced by applying high perilymph pressure above 1, 000 mm H2O, and same cochlear potential changes as alternation of the perilymph pressure with no perilymph leak was observed. Cause of the SNHL and histopathology were discussed.
