Sudden Sensorinerual Hearing Loss (SSNHL)

We estimate sudden sensorineural hearing loss (SSNHL) to affect over 7000 Australians each year. As the name suggests the hearing loss is sudden and onset can occur at any time. Although SSNHL can affect all ages, it is typically seen in adults aged between 40-60 years old (1), which is of particular interest to us given Tasmania’s ageing population. If you notice a drop in your hearing please book an appointment with your audiologist immediately as timing of treatment is crucial.


Unfortunately 85-90% of cases are idiopathic, meaning the cause is unknown (2, 3). It has been wildly postulated that SSNHL arises when there is a vascular disruption in the blood vessels supplying the cochlea (hearing organ), however there is little histological evidence in the literature to support this claim. In most instances only one ear is affected and is often accompanied by tinnitus (ringing in the ear). Other clinical presentations may include aural fullness (feeling of blocked ear) and vertigo (dizziness) (4).  


SSNHL can be identified via a comprehensive audiological assessment by your local audiologist. The medical criteria for SSNHL encompass a drop of 30dB HL or more measured on a standard pure tone audiogram in up to three adjacent frequencies over 72 hours or less (5). Once the hearing results are obtained your audiologist can make a comparison to your previous results and advise you appropriately.

Take home message

SSNHL is a medical emergency. Urgent Ear Nose and Throat (ENT) Specialist referral is warranted for patients identified with SSNHL. Sadly, patients who experience SSNHL often delay seeking medical attention, leading to poorer long-term outcomes (5). Correct medical management, in an appropriate time frame, may improve the chances of patients recovering some or all of their hearing (6, 7).



  1. Hughes, G. B., et al. (1996). "Sudden sensorineural hearing loss." Otolaryngologic Clinics of North America 29(3): 393-405.
  2. Wei, B. P., et al. (2006). "Steroids for idiopathic sudden sensorineural hearing loss." The cochrane library.
  3. Penido, N., et al. (2009). "Classification and hearing evolution of patients with sudden sensorineural hearing loss." Brazilian Journal of Medical and Biological Research 42(8): 712-716.
  4. Oh, J.-H., et al. (2007). "Bilateral versus unilateral sudden sensorineural hearing loss." Otolaryngology--Head and Neck Surgery 136(1): 87-91.
  5. Rauch, S. D. (2008). "Clinical practice. Idiopathic sudden sensorineural hearing loss." N Engl J Med 359(8): 833-840.
  6. Schreiber, B. E., et al. (2010). "Sudden sensorineural hearing loss." The Lancet 375(9721): 1203-1211.
  7. Moskowitz, D., et al. (1984). "Steroid use in idiopathic sudden sensorineural hearing loss." The Laryngoscope 94(5): 664-666.