Sudden hearing loss, also known as sudden sensorineural hearing loss (SSHL) or sudden deafness, happens quickly, at most over 3 days, and often in just one ear. The condition is caused by swelling that affects the hearing nerves in the inner ear. It is a medical emergency.
Sudden hearing loss is often first noticed when you wake in the morning and getting out of bed realise that your hearing is gone or diminished. A typical symptom is that hearing is so muffled that normal speech sounds like a whisper. You may notice it when listening on earphones or holding a phone to the affected ear, and it can cause vertigo, balance problems, and tinnitus. There is usually no associated pain, but it can be accompanied by an infection that causes paralysis around the affected ear.
The specific causes are difficult to identify; it may be an infection, head trauma, circulatory or auto-immune disease, medication, a neurological issue or tumour growth. There are few clinical signs and the ear canal and eardrum look normal. An audiogram is the best diagnostic test, and blood tests and an MRI scan may help to identify its cause.
Meningitis is an extreme illness that causes sudden hearing loss. Previously, testing patients’ hearing has been low on the hospital treatment list, but new protocols are being implemented by the Ministry of Health to urgently refer meningitis patients to audiologists and ENTs.
Meningitis causes rapid and extensive swelling in the inner ears and ossification sets in within three to four days. Severe ossification can obliterate the inner ear so that hearing aids won’t work, and whereas cochlear implants can be effective they must be inserted within a three- to four-week period before ossification makes it impossible.
Sudden hearing loss can be treated to minimise the damage, but recovery is less likely if the loss is severe or too much time has passed before treatment is started. Typically, treatment involves an anti-inflammatory drug such as prednisone to reduce the swelling, and other drugs to improve blood circulation to the inner ear. It is important to rest and avoid strenuous lifting or straining. If your hearing has been damaged, your audiologist will help you adjust to your new hearing normal. Hearing aids may be prescribed to lift your hearing in the ear, or if the damage is severe, cochlear implants may be helpful.
See your audiologist urgently
“Too often clients go to see their GP but hold back on seeing an audiologist or ENT specialist, thinking it will go away. But hearing loss has many idiosyncrasies and sudden hearing loss warrants close investigation before permanent damage occurs. Treatment should be started within 48 hours, so the sooner it is diagnosed the better. We urge you to come to see us at the same time as your GP, and indeed your audiologist appointment may be the more important,” Simon Melville says.