Causes of sensorineural hearing loss (SNHL)

When it comes to hearing loss, there are three main types: sensorineural, conductive and mixed. Sensorineural is the far more common type of hearing loss, affecting roughly 9 out of 10 people with hearing loss. 

Having sensorineural hearing loss means there is damage either to the tiny hair cells in your inner ear (known as stereocilia), or to the nerve pathways that lead from your inner ear to the brain. It normally affects both ears. Once you develop sensorineural hearing loss, you have it for the rest of your life. It can be mild, moderate, severe or profound. 

What causes sensorineural hearing loss (SNHL)?

The causes of this type of hearing loss are generally sorted into two categories: acquired or congenital. Most people have acquired hearing loss. 

Acquired sensorineural hearing loss 

Acquired means the hearing loss develops after a person is born, usually later in life. Causes can include:

• Aging: One of the most common conditions of growing older is presbycusis, or age-related hearing loss, affecting one in three Americans between the ages of 65-74. Because this type of loss occurs over time, typically in both ears, it’s sometimes difficult to notice.
• Noise: Noise-induced hearing loss (NIHL) can be caused by exposure to a one-time loud noise, such as an explosion or gunfire, or from sounds louder than 85 decibels (dB) over an extended period of time. If you have to shout to be heard or your ears ring after attending a live concert or ballgame, your hearing health is at risk.
• Disorders and infections: Viral infections—including measles, meningitis and mumps—can cause sensorineural hearing loss. So too can autoimmune disorders like lupus and thyroiditis.
• Head or acoustic trauma: Damage to your inner ear also can be caused by a blow to the head or exposure to extremely loud noise, such as an explosion. Many veterans suffer from sensorineural hearing loss due to time they spent around firearms, artillery and jet engines. 
• Tumors: Examples of common tumors that can affect hearing include acoustic neuroma and cholesteatoma, an abnormal skin growth in the middle ear.
• Medications: More than 200 medications and chemicals are ototoxic, or damaging to your hearing health. Some of those known to cause permanent damage include certain types of antibiotics, anti-inflammatory medications and cancer chemotherapy drugs.

Congenital sensorineural hearing loss

Congenital sensorineural hearing loss happens during pregnancy. It's far more rare. Some causes include prematurity, maternal diabetes, lack of oxygen during birth, genetics, and infectious diseases passed from the mother to child in the womb, such as rubella. 

Thanks to newborn screening, some children born with hearing loss are diagnosed right away and treated with hearing aids or cochlear implants as soon as possible to help with language development.  

What about sudden sensorineural hearing loss?

Most of the time, acquired sensorineural hearing loss occurs gradually. However, in rare cases, people can develop sudden sensorineural hearing loss, leading to sudden deafness in one ear. If this happens to you, it's important to seek medical care right away. 

How does it affect how you hear?

Sensorineural hearing loss affects both the loudness and the clarity of the sounds you hear. You may also experience a reduced range of sounds you find comfortable. Meaning, soft and normal sounds are too soft, but loud sounds very quickly get too loud and may really bother you. (In audiological terms, this is known as "recruitment.")

Sensorineural hearing loss can affect all ranges of hearing. For people with age-related hearing loss, however, it's typical to experience what's known as high-frequency hearing loss, which results in the reduced ability to hear high-pitched sounds.

Many people with sensorineural hearing loss report that they can hear but struggle to understand speech. This is especially true in the presence of background noise, and it can be frustrating and exhausting to deal with. Ringing in the ears, or tinnitus, is common when a person has hearing loss. 

Treatment for sensorineural hearing loss

Most often, the recommended treatment is hearing aids programmed to your unique hearing loss. Simply amplifying all sounds won't help you hear better because some sounds would still be distorted. Proper testing and fitting is vital. 

In some cases—especially if hearing loss is severe or profound—a cochlear implant may be the better option. 

If you suspect you may have sensorineural hearing loss, the first step to better hearing is to have a thorough hearing examination from a qualified hearing healthcare professional. They can work with you to determine the cause and extent of your hearing loss, as well as develop an individualized plan to treat it. To find a hearing professional at a clinic in your area, visit our directory of consumer-reviewed clinics.