Sudden hearing impairment, or sudden deafness, can be caused by the middle ear becoming blocked or by a problem affecting the brain, inner ear or auditory nerve. The middle ear is most commonly obstructed when an infection causes a buildup of fluid, a condition which often resolves on its own. Loud noises and injuries can also damage the hearing structures in the middle ear, leading to a sudden hearing impairment, possibly requiring surgery. What is known as sudden sensorineural hearing loss, or SSHL, affects the inner ear, brain or auditory nerve, and most often has no known cause. In a minority of cases, causes may be found, such as infections, drugs, injury, immune disorders, and conditions such as Ménière’s disease.
When sudden hearing impairment causes a hearing loss of more than 30 decibels and takes under three days to develop, it can be defined as SSHL. Typically, with SSHL, the hearing problem is discovered upon waking one morning. A loud popping sound is sometimes experienced just before hearing disappears. Normally, only one ear is affected by the sudden hearing loss, which may be associated with the buzzing or ringing noises of tinnitus. Most people require no treatment and recover within a few weeks, but sometimes the hearing impairment persists and progressively worsens.
The treatment of SSHL where there is no known cause may involve taking steroid and antiviral medication. It is thought that inhaling a mixture of carbon dioxide and oxygen gases can help, by improving the supply of blood and oxygen to the ear. In some cases, following a diet which is low in salt may be beneficial. If a specific cause of the sudden hearing impairment can be found it is treated, if possible.
One specific cause of SSHL is meningitis, an infection that inflames the tissues around the brain. Meningitis can often be treated with antibiotics. Mumps and measles can also lead to sudden hearing impairment, and treatment relies on supporting the patient until recovery occurs. Another cause of SSHL is Ménière’s disease, an illness where attacks of dizziness, tinnitus and a sensation of fullness in the ear are experienced. There is no cure but the symptoms may be treated.
Injury to the inner ear, auditory nerve or brain may be caused by factors such as extremely loud noises, head trauma, ear surgery, or pressure changes, such as those experienced while diving. The resulting damage could lead to a sudden hearing impairment which may not be treatable. Where the problem persists, professional support may be necessary to help a person adjust to being hard of hearing and having to wear a hearing aid.
