What is sudden hearing loss?
Sudden sensorineural hearing loss means that the inner ear (cochlea) or the hearing nerve stops working properly, usually in one ear, over up to 3 days. This differs from conductive hearing loss, in which sound cannot get through the ear canal or middle ear because of wax or fluid. Sudden hearing loss affects roughly 5–27 per 100,000 people a year, mostly adults in their 40s to 60s. See clogged ears and fluid in the ear for the more common conductive causes.
Symptoms and how it feels
- Muffled, reduced or lost hearing in one ear that develops over minutes to days; many notice on waking or on the phone.
- A loud “pop” just before the loss in some people.
- Tinnitus (ringing, hissing or buzzing) in the affected ear. See tinnitus treatment.
- A feeling of fullness or pressure in the ear.
- Dizziness or vertigo in about a third of people.
- Distorted or tinny sound (diplacusis) or difficulty understanding speech.
- Less often, hearing loss in both ears at once, which needs even more urgent evaluation.
Possible causes
- Idiopathic: no cause found in about 90% of cases; viral infection or inner-ear circulation problems are suspected.
- Viral infections such as mumps, measles, herpes viruses, flu and others.
- Vascular problems: reduced blood supply to the cochlea.
- Autoimmune disease: Cogan’s syndrome, lupus and others.
- Ménière’s disease. See Ménière’s disease.
- Acoustic neuroma (vestibular schwannoma), a benign tumour of the hearing nerve; found on MRI in a small proportion.
- Head or ear injury, barotrauma and perilymph fistula.
- Ototoxic medicines such as certain antibiotics, chemotherapy and high-dose aspirin.
- Neurological causes such as stroke or multiple sclerosis, with other signs.
- Infections such as syphilis, Lyme disease and meningitis.
Why it must be treated quickly
Studies show that hearing recovery is better the sooner treatment starts, ideally within the first 2 weeks and especially within 72 hours. Delays reduce the chance that steroids will help. Waiting to see if it “clears up” can cost hearing permanently. It is also essential to rule out blocked ears (wax, fluid) that are treatable, and rare but serious causes. Treat any sudden hearing change as an emergency until a doctor tells you otherwise.
How it is diagnosed
- Examination of the ear canal and eardrum to rule out wax, infection and fluid.
- Tuning fork tests (Weber and Rinne) to distinguish conductive from sensorineural loss.
- Pure-tone audiometry, the key test, to confirm the loss and its size; speech audiometry too.
- MRI with contrast of the brain and internal auditory canals to look for acoustic neuroma and other causes, in most patients after treatment starts.
- Blood tests (for infection, diabetes, autoimmune markers and others) as indicated.
- Balance testing if there is vertigo.
Treatment
- Oral corticosteroids (such as prednisolone, high dose for about 1–2 weeks then tapered), started as early as possible.
- Intratympanic steroid injection through the eardrum, as salvage treatment or when oral steroids cannot be used, such as in some people with diabetes.
- Hyperbaric oxygen therapy is used in some centres, evidence is limited.
- Antivirals are not routinely recommended.
- Treatment of the underlying cause where identified.
- Hearing aids, CROS systems or cochlear implants if hearing does not recover.
- Tinnitus management and vestibular rehabilitation if needed.
- Rest, protecting hearing from noise and following up with repeated hearing tests.
Outlook and recovery
Roughly 32–65% of people recover some hearing spontaneously, and treatment improves the chance and extent of recovery. Most recovery occurs in the first 2 weeks, and can continue for a few weeks to months. Factors linked with a better outcome include earlier treatment, milder loss, lower-frequency loss, younger age and no vertigo. Severe loss, vertigo and delayed treatment predict poorer recovery. Repeat audiograms track progress.
What to do if it happens
- Seek medical help the same day: an emergency department, urgent care or ENT clinic.
- Do not wait or try ear drops, wax removal or home remedies first.
- Note when it began, which ear, associated symptoms (dizziness, ringing, pain, discharge) and recent illness, injury, flights, medicines or loud noise.
- Avoid very loud noise, and do not insert objects in the ear.
- Have someone accompany you if dizzy.
- Ask for an audiogram and whether steroids are appropriate for you.
- Mention diabetes, ulcers, infection or other conditions before steroids are started.
Protecting your hearing in general
- Avoid prolonged loud noise; use ear protection at concerts, with power tools and at work.
- Keep volume on headphones moderate, below about 60% for no more than an hour at a time.
- Have regular hearing checks if you have risk factors or take ototoxic medicines.
- Control blood pressure, diabetes and cholesterol, which affect the inner ear’s blood supply.
- Do not smoke.
- See a doctor early for ear infections.
- There is no proven way to prevent idiopathic sudden hearing loss.
When it is an emergency
- Any sudden loss or marked change in hearing, particularly in one ear.
- Sudden hearing loss in both ears.
- Hearing loss with severe vertigo, vomiting, facial weakness, double vision, severe headache or slurred speech.
- Hearing loss after a head injury or loud blast.
- A history of cancer, immune problems or recent infection with new hearing symptoms.
- Persistent hearing loss that does not improve after a week.
Three common situations
A 50-year-old who wakes with muffled hearing and ringing in the right ear: needs same-day assessment; steroids are most effective early.
A person with a blocked ear for 3 days after a cold: likely conductive (fluid or wax), but a doctor should confirm with an exam and hearing test.
Hearing loss in one ear with dizziness and slurred speech: call emergency services.
Key points to remember
Sudden hearing loss is an emergency: see a doctor the same day. Steroids started early improve the chance of recovery, and tests such as an audiogram and MRI look for causes. Protect your hearing and do not wait. Our ENT team can arrange urgent hearing assessment.
This guide is for general information and does not replace an examination by your own doctor or ENT specialist.
Questions about sudden hearing loss
These answers are general information and do not replace an examination or individual medical advice.
What causes sudden hearing loss?
Most cases are idiopathic; viral infection, poor inner-ear blood flow, autoimmune disease and rarely a tumour are possible causes.
Is sudden hearing loss an emergency?
Yes, treatment within days gives the best chance of recovery.
Can hearing come back?
About half to two thirds recover some or all hearing, especially with early treatment.
What is the treatment?
Usually oral steroids started promptly, sometimes steroid injections behind the eardrum.
Could it just be earwax?
Possibly, but only a doctor can tell; sudden loss must be examined and tested.
Do I need an MRI?
Often yes, to look for causes such as an acoustic neuroma.
Sources
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.