Idiopathic sudden sensorineural hearing loss, or sudden deafness, is the acute onset of hearing loss of at least 30 dB in 3 connected frequencies occurring instantaneously or over a period of up to 3 days.1 Sudden hearing loss is thought to be relatively rare,2 occurs mainly in patients between the ages of 30 and 60 years, and can be devastating for the patient. Therefore, sudden hearing loss should be treated as a medical emergency. The natural course is characterized by spontaneous recovery among approximately 50% of patients.3,4 Accurate estimates of incidence are difficult to obtain because a significant number of patients who spontaneously recover do not seek medical attention.5 As the term idiopathic implies, the etiology and pathophysiology of hearing loss are unknown. Possible causes include infections (especially viruses), autoimmune disease, circulatory problems, and neurological disease, including multiple sclerosis. Treatment options include oral steroids, intratympanic steroid injections, oral antivirals, vasodilators, diuretics, hyperbaric oxygen therapy, and vitamins.6 As a result of the high rate of spontaneous resolution, multiple potential causes, and absence of validated tests for etiological identification, the evaluation of treatment effectiveness is difficult.