Sudden sensorineural hearing impairment has occasionally occurred in adults in association with viral or bacterial infections. Inability to demonstrate pathogenic organism, in such cases, has suggested a viral etiology. Recently, the authors experienced a case of the mixed type hearing impairment due to E-H fever. This 24 year old male patient, in whom sensorineural impairment due to previous ear surgery, familial disease, noise exposure, fistula, ototoxic drugs or presbycusis were ruled out, had a history of the E-H fever about 1 year ago, thereafter hearing impairment was developed. Now authors report it with the literatural review.