Types of Hearing Loss

Sensorineural Hearing Loss

Sensorineural hearing loss is the most common type of hearing loss. Sensory hearing loss occurs when the hair cells of the cochlea responsible for changing the vibrations of sound waves into nerve signals are damaged. These hair cells are responsible for generating and sending signals to the hearing nerve, which transmits sound information to the brain. These tiny hair cells can be abnormal at birth, or they can suffer damage during the lifetime of an individual. Prolonged exposure to environmental noise, like being in a loud workplace without wearing ear protection, or using headphones set to high volumes are common causes of sensory hearing loss. However, the vast majority of sensory hearing losses are ‘idiopathic’ in origin, meaning that we do not really understand why or how the changes to the sensory structures occur.

Most people with sensorineural hearing loss experience a gradual decline in their hearing. Sometimes, the hearing loss can be accompanied by other symptoms, like ringing in the ears (tinnitus), or dizziness and lightheadedness (vertigo). Sensorineural hearing loss can be inherited (genetic) or acquired (as a result of external causes like noise or disease), and can be congenital (present at birth) or develop later in life. The most common kind of sensorineural hearing loss is age-related hearing loss (presbycusis), followed by noise-induced hearing loss. In rare cases, sudden unexplained hearing losses can occur; sudden hearing changes can also happen due to exposure to certain life-saving medications or treatments. People with sensorineural hearing loss cannot regain their hearing. The good news is that this type of hearing loss is typically treatable through hearing aids.


Conductive Hearing Loss

Conductive hearing loss occurs when sound does not move effectively through the ear canal to the eardrum and the tiny bones (ossicles) of the middle ear. One of the most common causes of conductive hearing loss is a blockage in the external ear canal. This can be caused by earwax, or physical changes in the ear canal like benign bony growths. Ear infections can also contribute to conductive hearing loss. In some cases, middle ear infections or even allergies can cause fluid to fill the middle ear. When this happens, the ear drum cannot vibrate the way it does when sound enters the ear canal in normal hearing.


Unlike sensorineural hearing loss, which represents the majority of hearing loss cases, conductive hearing loss can often be treated medically or surgically.