Sudden hearing loss in one or both ears may indicate an infection, ear wax, a head trauma, a tumor, or other health problems. Some of these may need urgent treatment. There may also be dizziness, tinnitus, and other symptoms.

Tinnitus and other symptoms sometimes accompany sudden hearing loss. The condition has various potential causes.

In the United States, there are around 66,000 new cases of sudden sensorineural hearing loss annually. The condition affects 5–27 people in every 100,000 per year.

This article explores what hearing loss is, its possible causes, and treatment.

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People who experience sudden hearing loss may first notice the condition when they attempt to use the ear that has lost hearing. This may be while talking on the phone or upon waking in the morning. Some people report hearing a loud popping sound before they lose hearing in an ear.

Sudden hearing loss often occurs in only one ear, which doctors refer to as unilateral hearing loss. One ear may function regularly, while a person may have difficulty hearing clearly with the other.

A person with hearing loss may also experience:

  • dizziness
  • a sensation of fullness in the ear
  • tinnitus
  • vertigo
  • inability to hear clearly while in a noisy area
  • muffled sound
  • difficulty following conversations in a group
  • difficulty hearing high pitched noises

There are a variety of potential causes of sudden hearing loss in one ear.

Sudden sensorineural hearing loss

Sudden sensorineural hearing loss (SSHL), which people also refer to as sudden deafness, typically affects one ear. SSHL involves a rapid, unexplained loss of hearing.

It most often affects people in their late 40s to early 50s. Most people who receive an SSHL diagnosis do not know the cause of the condition. Around 10% of cases that doctors diagnose have an identifiable cause, such as:

Tumor

An acoustic neuroma, which doctors also refer to as vestibular schwannoma, is a type of benign (noncancerous) tumor that affects the nerves that join the inner ear and the brain.

Schwann cells cover almost all the nerves in the body. When they multiply too fast around the eighth cranial nerve, a person may develop an acoustic neuroma. The tumor can prevent the nerves responsible for balance and hearing from functioning correctly, which can cause:

Although acoustic neuromas typically grow slowly and are benign, a person can experience symptoms suddenly. The tumor may also pose risks to health besides hearing loss.

Traumatic brain or head injury

A traumatic brain injury or head injury can cause sudden hearing loss in one ear. The hearing loss can be conductive, which means sound cannot reach the inner ear, or sensorineural, in which something causes damage to the structures in the inner ear or auditory nerve.

Diseases

Some diseases may cause hearing loss. These include:

  • Autoimmune inner ear disease: This is an inflammatory condition in which the immune system mistakenly attacks the inner ear.
  • Otosclerosis: This is a middle ear disease that affects the small bones of the middle ear. The bones cannot move, which can result in conductive hearing loss.
  • Ménière’s disease: This is an inner ear disease that experts do not know the exact cause of. Experts characterize it as an abnormal amount of fluid in the inner ear. It can cause sensorineural hearing loss and tinnitus.

Ear infection or buildup of earwax

A buildup of earwax or an infection can lead to hearing loss.

Types of infection include otitis externa and otitis media with effusion. Otitis externa involves inflammation in the outer ear. Otitis media with effusion is an infection that can cause fluid to build up behind the eardrum.

A buildup of earwax can cause impaction, which can block a person’s ear and cause loss of hearing on one side.

Loud noise on one side

A loud noise such, as a siren or explosion close to the ear, can cause sudden noise-induced hearing loss in one ear.

People sometimes ignore sudden hearing loss in one ear because they assume colds or allergies are the cause of the condition. However, sudden hearing loss in one ear can indicate a medical emergency, and a person should not ignore the condition. If someone experiences sudden hearing loss, they should contact a doctor.

Treatment of sudden hearing loss in one ear varies depending on the cause of the hearing loss.

SSHL

Because doctors often do not know the cause of SSHL, they may treat the condition with corticosteroids. These can help reduce inflammation and help a person’s body fight illness. If the condition does not respond to this treatment, a person may require a hearing aid or cochlear implant.

Acoustic neuroma

Treatment for this tumor may involve observation and monitoring in some cases. These include if the tumor is small and the person is an older adult or has several comorbidities. In other cases, a doctor may treat the tumor with stereotactic radiation or surgery.

Head trauma

If a person has a brain injury, a doctor may treat the injury differently depending on the severity of the trauma. For a mild brain injury, a person may require monitoring and no further treatment. In more severe cases, a person may require surgery to remove clots or blood pools, repair skull fractures, or relieve pressure on the brain.

Diseases

A doctor will treat each disease that can cause hearing loss differently.

  • Autoimmune inner ear disease: Doctors typically treat this with corticosteroids and immunosuppressive therapy.
  • Otosclerosis: Doctors may recommend monitoring the condition, wearing hearing aids, fluoride supplementation, and in some cases, surgery.
  • Ménière’s disease: There is no cure for this disease, so treatment typically focuses on easing symptoms. Treatment may include medications for dizziness, dietary changes, and cognitive behavioral therapy.

Earwax or infection

Doctors may gently suction or flush out earwax. An infection may resolve without treatment, or a doctor may prescribe antibiotics.

There are many potential causes of sudden hearing loss in one ear. Some causes may indicate a medical emergency, such as a traumatic brain injury. It is important that a person contacts a doctor if they experience sudden hearing loss.

Other causes of sudden unilateral hearing loss include a buildup of earwax, infection, or exposure to loud noise.

The treatment for sudden hearing loss in one ear will depend on the cause. Treatment can range from monitoring the condition to surgery.