The sudden onset of severe hearing loss is almost always a dramatic experience. The results can be very annoying if the loss occurs in only one ear. The detection of sound and hearing ability when there is sound in the background, as in restaurants and in difficult acoustic environments (e.g. in a classroom) becomes very difficult. Fortunately, the sudden loss of hearing in both ears is rare. If tinnitus is observed, the problems are even worse. A sudden hearing loss can result from many causes, but how sudden can be called sudden and what percentage is needed to be characterized as hearing loss?
The standard accepted definition of sudden hearing loss is hearing loss greater than 30dB on average three frequencies, which occurs within 3 days. The causes of such aids are: