Select Page

Hearing loss affects millions of people around the globe. According to the World Health Organization (WHO), it is experienced by almost 20% of the entire population! There are three types of hearing loss, but more than 90% are attributed to sensorineural hearing loss.

What Is Sensorineural Hearing Loss?

Hearing starts with the tiny hairs found in the cochlea, the spiral-shaped, fluid-filled organ in the inner ear located inside the temporal bone. It converts vibrations from sound waves into electrical impulses that the auditory nerve carries to the brain through several information-processing centers.

Sensorineural hearing loss (SNHL) is a condition caused by damage to the:

This condition may not be life-threatening, but it is permanent. Hence, it can interfere with your ability to interact with others, leading to a poor quality of life. Loss of hearing can cause moderate to severe depression according to a 2005 to 2010 survey.

If the damage or irregularities occur too quickly, it may result in fatality.

Sudden sensorineural hearing loss (SSNHL) is a serious medical emergency, resulting in an inability to hear sounds of at least 30 decibels in less than 72 hours. It affects 11 to 77 out of every 100,000 people every year and almost always leads to unilateral hearing or sounds being heard on only one side.

Types of Sensorineural Hearing Loss

There are two types of sensorineural hearing loss:

  • Bilateral: Hearing loss in both ears
  • Unilateral: Hearing loss (to some degree) in one ear

Depending on the degree of damage, SNHL can be:

  • Mild: Characterized by an inability to detect sounds between 26 to 40 decibels
  • Moderate: Loss of hearing between 41 to 55 decibels
  • Severe: Inability to hear sounds greater than 71 decibels.

Something to remember: SNHL can also be asymmetrical, which means that there’s hearing loss in both ears, but one is far more affected than the other.

What Causes Sensorineural Hearing Loss?

SNHL can be congenital or acquired. Potential causes include:

  • Birth Abnormalities: Syndromic sensorineural hearing loss affects 1 to 3 newborns out of every 1,000. Twenty percent to 30% experience profound hearing loss. More than 50% of cases are linked to over 100 genes while the rest are attributed to environmental factors.
  • Certain Types of Diseases: SNHL can be brought on by a disease of the blood vessels, Meniere disease, and autoimmune disorders like lupus and thyroiditis.
  • Injuries: Blunt or penetrating trauma, such as the dislocation or fracture of the ossicular chain and brain injury, can result in sensorineural hearing loss.
  • Loud Noises: Exposure to 85 decibels or higher can lead to SNHL. For context, this could be the sound of a car horn, firecrackers, gas-powered leaf blowers, approaching subway trains, or city traffic heard from inside the car.
  • Medication: Cisplatin and aminoglycosides may cause SNHL. Other ototoxic drugs may include aspirin, gentamicin, quinine, and streptomycin.
  • Normal Aging: Presbycusis or age-related hearing loss happens gradually, often presenting itself in individuals who are in their 50s. It targets 1 in 3 people over 65, affecting their ability to hear high-pitched noises.
  • Specific Activities: Anything that causes abrupt changes in air pressure can put you at risk for SNHL. For example, SCUBA diving.

Additionally, it can be caused by a rubella infection during pregnancy or exposure to diseases like measles, meningitis, multiple sclerosis, mumps, and scarlet fever.

Symptoms of Sensorineural Hearing Loss

Common symptoms of SNHL include but aren’t limited to:

  • Sounds that seem overly loud in one ear
  • Sounds that seem muffled when spoken at normal volumes
  • An inability to hear and distinguish soft- or high-pitched sounds
  • Difficulty hearing or understanding the voices of children or females
  • Problem hearing or understanding words when there’s background noise or when two or more people are talking at the same time

You may also feel off-balance and dizzy or experience ringing in your ears (tinnitus).

How Is Sensorineural Hearing Loss Diagnosed

Doctors use several tools to diagnose SNHL:

Physical Exams

After taking your medical history, a healthcare provider will examine your ears to find signs of inflammation and other causes of hearing loss, such as earwax buildup.

They may also conduct a “whispered voice” test to detect hearing impairment. During this test, the doctor will whisper words or numbers in your ear and ask you to repeat them. It’s a simple yet effective method for seeing how you detect sounds.

Tuning Fork Tests

Tuning fork tests like Rinne’s and Weber’s can help assess whether the hearing loss is conductive or sensorineural. They were introduced in the early 1800s, making them seem archaic. But using the acoustic, two-pronged, small steel instrument continues to be popular.

Audiogram

Your doctor could prescribe an audiogram to better identify hearing deficits.

During an audiometry hearing test, the audiologist will play sounds of different frequencies and intensities through headphones to determine the type and degree of hearing loss. This helps them offer more informed treatment options.

However, since tests like pure tone audiometry rely on the patient’s responses, they may not be as reliable for certain demographics—say, small children like toddlers.

Speech audiometry and head CT scans can also be used as diagnostic tools.

Treatments for Sensorineural Hearing Loss

Sensorineural hearing loss can be managed with:

Medications

Steroids will be your first line of defense in managing the symptoms of SNHL. They’re typically used for treating sudden time-critical sensorineural hearing loss and are often followed by a recommendation to the otolaryngology department. These steps lead to early detection, diagnosis, and treatment.

Hearing Aids

Hearing aids come in three styles: Behind-the-ear (BTE), in-the-ear (ITE), and canal. Your doctor will make a choice based on your hearing loss symptoms. The preferred placement can also be a factor in their decision.

Hearing aids can go a long way in improving hearing. About 2 million people benefit from them.

Cochlear Implants

In cases of severe sensorineural hearing loss, your doctor may use a cochlear implant to restore your sense of hearing. This FDA-approved electronic device will pick up sounds from your surroundings, convert them into electronic impulses (basically doing the work of the cochlea), and deliver the signals to your auditory nerve to improve hearing. 

Take Home Message

Sensorineural hearing loss is usually permanent which can be a daunting idea. You can delay its onset and minimize your risk by protecting your ears from loud noises, keeping the volume of your headphones low, using earplugs if you work in construction and other noisy jobs, and getting regular hearing tests.