Sensorineural deafness

Nerve deafness; Hearing loss - sensorineural; Acquired hearing loss; SNHL; Noise-induced hearing loss; NIHL; Presbycusis

Sensorineural deafness is a type of hearing loss. It occurs from damage to the inner ear, the place of origin of the nerve that runs from the ear to the brain (auditory nerve), or the brain.

Ear anatomy

The ear consists of external, middle, and inner structures. The eardrum and the 3 tiny bones conduct sound from the eardrum to the cochlea.

We often take for granted all of the sounds around us, the bark of a dog, the buzz of a bee, or the melody of our favorite symphony. Yet for many people, the world is a very quiet place. They've lost the ability to hear sounds in one or both ears. Let's talk about hearing loss. To understand how you lose hearing, you first need to know what normally happens inside your ear when you hear. Say that a fire engine roars past. First, the sound of the siren reaches your eardrum in your outer ear. Your eardrum vibrates, which moves three tiny bones in your middle ear. These bones push the sound along to the cochlea, a fluid-filled chamber in your inner ear. The cochlea is lined with tiny hairs that vibrate when the sound waves hit them. These hairs convert the sound waves into an electrical signal. That's when your brain realizes that a fire engine is headed toward you. Hearing loss can have many different causes. Loud noises, pressure changes while you're scuba diving, or a head injury can all damage the delicate structures in your ear that allow you to hear. Infections like measles, mumps, and meningitis can also damage the ear. Sometimes earwax can build up in your ear and block your hearing like a plug. As you get older, you may gradually lose your hearing, even if you don't have an illness or injury. When the damage or other problem is to your outer or middle ear, it's called conductive hearing loss. For example, your eardrum may not vibrate when you hear sound. Or, the tiny bones in your middle ear may not move sound to the inner ear. Sensorineural hearing loss is caused by a problem in the inner ear. Often it's because the tiny hair cells that move sound through the ear don't work right because of damage or disease, and stem cells in the ear can't keep up with the repair. If you have problems with both your inner and outer ear, then you have mixed hearing loss. So, how do you treat hearing loss? If you're noticing that voices sound fuzzy and you can't make out what people are saying, see your doctor for a hearing test. The doctor will examine your ears, and give you a test called audiometry to check the type and amount of hearing you've lost. You may also have imaging tests such as a CT or MRI scan if you've had a head injury. A hearing aid can amplify sounds to help you hear more clearly. Today's hearing aids are so small they're barely noticeable. If you have a buildup of earwax in your ear, an ear syringe filled with warm water can help flush it out. Sometimes surgery can be done to fix damage in your ear and improve your hearing. Don't accept hearing loss as an inevitable part of growing older. See your doctor for a hearing evaluation. Often, hearing loss that's due to a problem in your outer or middle ear can be reversed. Protect the hearing that you do have by avoiding loud noises, and wearing earplugs when you have to be exposed to loud sounds.



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