Diagnostic criteria for sudden deafness by Japan's Sudden Deafness Research Committee (1973)

I) Main symptoms

1 Sudden onset of hearing loss

2 Sensorineural hearing loss, usually severe

3 Unknown etiology

II) Accessory symptoms

1 May be accompanied by tinnitus

2 May be accompanied by vertigo, nausea, and/or vomiting, without recurrent episodes

3 No cranial nerve symptoms other than from the eighth nerve

Definite: All of the above criteria (=>idiopathic sudden deafness)

Probable: Main symptoms 1 and 2

Reference:

Nomura Y. Acta Otolaryngol Suppl (Stockh) 1998;S456:7-8.