The sudden onset of severe hearing loss is always a very negative experience. Its results can be very troublesome when the loss is unilateral; the perception of sound and especially in environments with noise in the background, such as restaurants, becomes difficult. In cases where additional tinnitus is reported, the patient’s difficulty to hear clearly is increased dramatically. Sudden loss of hearing in both ears is very rare.
The commonly accepted definition of sudden hearing loss is an average hearing loss of more than 30 dB in three frequencies, which occurs over a period of three days. The causes of such hearing loss are: