What is a sudden hearing loss? – Definition of sudden hearing loss
Sudden hearing loss - or more precisely a sudden sensorineural hearing loss (SSHL) - is a hearing loss greater than 30 dB in three contiguous frequencies that occurs over a period of less than three days.
Sudden sensorineural hearing loss (SSHL) is an acute hearing loss and may for example be noticed upon awakening in the morning or develop rapidly over hours or days. You may hear a 'pop' in the ear prior to the hearing loss.
Many patients with a sudden sensorineural hearing loss also experience tinnitus. Vertigo is also present in cases of the sudden sensorineural hearing loss.
A sudden hearing loss may also occur because of build-up of earwax in the ear canals. This is not a sudden sensorineural hearing loss, but a temporary conductive hearing loss, which can typically easily be cured by a doctor by removal of the earwax.
Causes of sudden hearing loss
What causes sudden hearing loss? Among the many possible sudden hearing loss causes are:
- Earwax in the ear canals
- Viral infections. Some patients with SSHL report suffering from an upper respiratory infection within a month before the hearing loss. What virus causes sudden hearing loss? Viruses associated with sudden hearing loss include mumps, measles, rubella, as well as meningitis, syphilis and AIDS, among many others.
- Tumours. A variety of tumours in the ear, benign as well as malignant, may cause SSHL.
- Head trauma affecting hair cells in the ear, eardrum or bones. Regaining hearing after a hearing loss that has been caused by a head injury can be expected partially or even totally.
- Drugs and insecticides. A long list of prescription drugs and chronic abuse of painkillers may cause sudden hearing loss. Insecticides such as malathion and methoxychlor have been associated with sudden hearing loss in both ears (binaural sudden hearing loss).
- Vascular disorders disrupting blood flow to the ear.
- Developmental abnormalities.
- Idiopathic disorders, such as multiple sclerosis, Meniere's disease and others.
How common is a sudden hearing loss?
It is estimated that one out of 5,000 adults experiences sudden sensorineural hearing loss each year. But the number could be higher as many cases of sudden hearing loss may be unreported and undiagnosed.
A study, "Incidence of sudden sensorineural hearing loss", found that there are more than 66,000 new cases of sudden sensorineural seen annually in the United States. During the years 2006 and 2007, the study found that the annual incidence of SSHL was 27 per 100,000 in the United States. The incidence increased with increasing age, ranging from 11 per 100,000 for persons younger than 18 years to 77 per 100,000 for persons 65 years and older.
A Korean study, "A Trend in Sudden Sensorineural Hearing Loss: Data from a Population-Based Study", found that over the 5-year study period from 2011 to 2015, the mean annual incidence of sudden sensorineural hearing loss was 17.76 cases per 100,000.
Sudden sensorineural hearing loss in one ear is much more common than a sudden hearing loss in both ears. A bilateral sudden hearing loss is rare. It is estimated that only around 2% experience a case of bilateral sudden sensorineural hearing loss.
Can you recover from a sudden hearing loss?
Yes, you can recover from a sudden hearing loss. Spontaneous recovery from sudden sensorineural hearing loss occurs in many cases.
The recovery time for sudden hearing loss is usually within the first two weeks. The chances of full hearing recovery are smaller for patients with severe loss of hearing and when the sudden sensorineural hearing loss is accompanied by vertigo. The younger the patient, the greater the likelihood of a full recovery.
Removal of earwax
If you have a sudden hearing loss because of build-up of earwax in your ear canals, a doctor can easily remove the earwax, which typically restores the hearing back to normal. Do not try to remove the earwax yourself or let your spouse or others try to do it. It may only make things worse and may damage parts of the ear including the eardrum.
What treatments exist for a sudden sensorineural hearing loss?
Just as the precise source of your sudden hearing loss may be hard to pinpoint, the treatment of sudden hearing loss may be difficult. It is strongly advised to see your doctor for a sudden hearing loss treatment on an emergency basis as soon as possible after the occurrence of SSHL in order to determine or eliminate causes demanding immediate attention.
However, the usefulness of medical sudden hearing loss treatment of itself is debatable. People who experience a sudden sensorineural hearing loss (SSHL) may be treated with steroids.
Whereas some specialists favour aggressive treatment of underlying causes in the hope of reversing or curing many cases of sudden hearing loss, others conclude based on earlier studies that their patients are equally likely to regain their suddenly lost hearing fully or partially whether they receive treatment or not.
However, some recent studies indicate improved results in patients receiving some forms of steroid therapy when this sudden hearing loss treatment is deemed appropriate.
For some patients, a sudden sensorineural hearing loss becomes permanent. The treatment options for sudden hearing loss for these patients vary from hearing aids to hearing implants such as cochlear implants.
The vast majority of cases are those with sudden hearing loss in one ear. Unilateral hearing loss particularly affects communication in situations with background noise.
For the majority of the patients where the recovery from sudden hearing loss is not happening, the use of hearing aids is often the best treatment. Cochlear implants may be considered for SSHL patients with severe to profound hearing loss.
What should I do if I experience a sudden hearing loss?
If you experience a sudden hearing loss in one ear of you have got a sudden hearing loss in both ears, it is very important to seek medical advice from a doctor or an ENT-doctor as soon as possible.