A majority of cases of hearing loss is due to sensorineural hearing loss. Sensorineural hearing loss is hearing loss that is caused by damage or deficit of the auditory nerve, also called the eighth nerve, or the cochlea. Sensorineural deafness is sometimes called nerve deafness since it is often caused by a malfunction of the auditory nerve. This is in contrast to conductive hearing loss which is caused by a blockage of sound reaching the inner ear. In sensorineural hearing loss, the sound travels freely to the inner ear where the cochlea or auditory nerve fails to transmit the sound to the brain.

Sensorineural hearing loss is considered permanent hearing loss that cannot be surgically corrected. The hearing loss can range from mild loss of volume of sound to complete deafness. Sensorineural hearing loss can also affect the clarity of sound and the ability to understand people speaking. The hearing loss can start suddenly or gradually. Other symptoms of nerve deafness include dizziness or tinnitus which is a ringing in the ears.

The most common causes of sensorineural hearing loss are injuries during birth, diseases, genetic conditions, and drugs. Head trauma, aging, illness, tumors, and injury can be causes of nerve deafness. Noise exposure can also cause sensorineural hearing loss. Damage to the blood vessels to the cochlea can cause nerve deafness. This blood vessel damage can be caused by diabetes or degenerative cardiovascular disease. If the cause is unknown, the condition is called idiopathic sensorineural hearing loss.

When diagnosing hearing loss, the physician is likely to perform an ear exam and ask questions about the development of the hearing loss and conduct one or more hearing tests. People with cochlear impairment fail Otoacoutic Emissions Testing (OAE) which records sounds that the ear produces. Other testing can detect deficits of the eighth nerve.

Depending on the type and degree of hearing loss, a hearing aid may help someone with this type of hearing loss. Cochlear implants are sometimes used as a nerve deafness treatment. This treatment for sensorineural hearing loss works by implanting an electronic device that stimulates the auditory nerve from the cochlea.