Abstract
Today the noise susceptibility for the acoustic trauma is seriously discussed among some otologists for the industrial workers, however, there is not yet even a clue of the reliable procedure to solve this problem.
The author described 2 cases with sudden deafness by intense noise exposure on an occasion after the long durated noise-proof good condition of hearing in a same individual. The author deduced that this noise induced deafness, suddenly appeared, should be considered as a result of an acquired noise susceptibility, which might be concerned to a disorder of the tympanic muscle function.
