Otoacoustic emissions in sudden unilateral hearing loss associated with multiple sclerosis.

Sudden unilateral hearing loss may result from etiologies affecting cochlea, eighth nerve, or more central auditory tracts. Two case studies are presented in which the measurement of otoacoustic emissions helped rule out outer hair cell cochlear pathology. In both cases, the final diagnosis was sudden unilateral hearing loss associated with multiple sclerosis (MS). For one case, the sudden hearing loss was the first clinically recognized presenting sign of MS.