Abstract
Perilymphatic fistula is known to be a cause of acute, profound and reversible sensory hearing loss. However, it remains to be explained why such hearing loss was caused by perilymphatic fistula only. The exploratory tympanotomy we operated suggested that the hearing loss was possibly induced by aspirating air into the perilymphatic space. This assumption was verified by the experiment using guinea pig. Action potentials of the auditory nerve were registered; 1) Before and after air was aspirated into the scala tympani, 2) After the air was pushed out by pouring the perilymph back into the scala tympani. The experiment demonstrated that acute, profound and reversible hearing loss was developed by aspirating a very small amount of air into tha scala tympani.
