[Acute unilateral deafness caused by mumps--a case description].

Reports of the aetiology of mumps induced deafness in the auditory pathway have not appeared in the literature in recent years. It is now possible to distinguish between sensory deafness and other types of profound hearing loss by combining the results of promontory testing (PT) and electrocochleography (ECochG). A very extensive examination of a case of profound sudden hearing loss due to mumps is described. It was impossible to prove a relation between the mumps virus and sudden hearing loss in this case but the site of the lesion in the auditory pathway could be localised. The hearing loss in this case was of sensory type, profound, irreversible and resistant to treatment.