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Ear & hearing
Sudden hearing loss
The acute onset of hearing loss of 30 dB in three contiguous frequencies which may have occurred instantaneously or progressively over several days.
Clinical content by the surgeons of Sydney ENT Clinic · Updated October 2026
Patients often describe a numbness or blockage as opposed to an obvious hearing loss.
The incidence is 5 to 20 per 100,000 patients per year.
Untreated, spontaneous recovery has been reported to range from 30-60%.
While a viral or microvascular aetiolgy is proposed, it is essentially a diagnosis of exclusion: cerebellopontine angle tumours, auto-immune disease, multiple sclerosis (MS), infectious aetiologies, intralabyrinthine haemorrhage, perilymph fistula and Meniere’s disease must be excluded.
Poor prognostic factors include a severe, flat pattern to the hearing loss and associated vestibular dysfunction.
SSNHL is an otologic emergency which requires prompt diagnosis and institution of management in order to optimise the chance of recovery. The patient must be thoroughly informed as to the limitations of current treatments. There is evolving evidence that a subset of patients may benefit from intratympanic steroids. Bilateral sudden sensorineural hearing loss is much rarer, but is more likely to be associated with significant systemic disease.
Rehabilitation
Consideration must be given to hearing rehabilitation. Assistive listening devices and hearing aids are useful when there is measurable hearing. BiCross or a bone anchored hearing aid, BAHA is an option when there is a residual severe sensorineural hearing loss. It provides the sensation of binaural hearing in a majority of cases by re-routing a signal to the contra-lateral ear. The other option is cochlear implantation. This allows stimulation of the damaged cochlear allowing true binaural hearing, and is especially useful if tinnitus is a particular problem.
Tested at Kogarah on the day
Hearing tests with Precision Hearing are available in Suite 5 at the time of your appointment, and CT or MRI of the ear can be arranged at Lumus or Castlereagh Imaging within a few hundred metres of the clinic.
Frequently asked questions
Is sudden hearing loss an emergency?
Yes. A sudden drop in hearing in one ear — over hours or when you wake — should be treated as urgent: you need a hearing test and review by an ENT specialist within seven days, and sooner is better. Call any of our surgeons’ rooms and say that your hearing has dropped suddenly. Do not wait to see whether it comes back on its own, because treatment works best when it is started early.
What causes sudden hearing loss?
When there is no injury or other ear disease to explain it, sudden sensorineural hearing loss is thought to be inflammation of the inner ear. In younger people the most likely mechanism is reactivation of a dormant virus in the hearing nerve — similar to the way shingles reactivates in a skin nerve. In older people a microvascular event — a tiny ‘stroke’ within the blood supply of the inner ear, akin to the small-vessel damage diabetes causes in the eye or the fingers — becomes more likely. In practice there is no test that tells the two apart, and treatment is the same. Rarer causes include complications of cholesteatoma or chronic ear disease, a first attack of Ménière’s disease, and a vestibular schwannoma, which is why every case is investigated.
Will my hearing come back after sudden hearing loss?
There is no guarantee. Overall, about half of people regain functional, useful hearing in the affected ear; the other half are left with a permanent loss that usually needs a hearing aid. The outlook is better when the loss is milder and confined to the low frequencies, and worse when it is severe or accompanied by vertigo or imbalance. Age matters less than you might expect. Early treatment improves the odds.
What treatment is given and how quickly does it need to start?
Corticosteroids, given as a course of oral prednisone and/or injected through the ear drum into the middle ear (intratympanic steroid), together with investigation to exclude other causes. Antiviral drugs have no proven role. Ideally treatment starts within the first week — the sooner the better. Hyperbaric oxygen therapy is also used for sudden hearing loss, in a proper hyperbaric chamber; in Sydney this is provided by the Hyperbaric Medicine Unit at Prince of Wales Hospital, which aims to start treatment within two weeks of onset. Your surgeon can refer you directly and the unit will liaise with you.
Do I need an MRI after sudden hearing loss?
Yes — everyone. It is not usually urgent, and it is still needed even if your hearing recovers fully within a few weeks. The MRI looks at the inner ear and the hearing nerve to exclude a structural cause, in particular a vestibular schwannoma (acoustic neuroma), which can present for the first time as a sudden loss of hearing.
Who treats this at Kogarah
Complex otology, cochlear implantation and lateral skull base: Dr Sean Flanagan, Darlinghurst.
For GPs
Send the referral directly to the specialist’s rooms. If the right surgeon isn’t obvious, send it to any of us and we will place it.
Referral information