SENSORINEURAL HEARING LOSS
Sensorineural Hearing Loss occurs because of damage to the inner ear or to the neural pathways from the inner ear to the brain. About 90% of all people with hearing impairments are in this category making it the most common type of hearing impairment. Sensorineural hearing loss is often referred to as "nerve deafness", but this is not a good description because the damage usually occurs within the inner ear and not the hearing nerve.
Sensorineural hearing loss can be the result of trauma, such as a head injury. It can occur as a result of an infection that reaches the inner ear. Other common causes of sensorineural hearing loss are ageing and exposure to loud noises. The inner ear normally deteriorates with age. So almost everyone past the age of 65 will experience some sensory hearing loss. This type of hearing loss is usually not medically or surgically treatable, however, most people with this hearing loss find the wearing of hearing aids to be of significant benefit.
CONDUCTIVE HEARING LOSS
Conductive Hearing Loss occurs when the "outer" or "middle" ear fail to work properly. Blockage of the outer ear can cause loss of hearing. A common problem in the outer ear canal is the build up of wax. Sounds become "blocked" and are not carried all the way to the inner ear. Another conductive loss is when there is a disruption of the eardrum or bones of the middle ear. Any malfunction of the middle ear can cause a hearing loss. The most common middle ear problem results from a build up of fluid in the middle ear. Fluid is secreted by cells in the middle ear to lubricate the mechanism. As fluids build up, it is drained by opening the Eustachian tube, a tube which opens to the throat. The Eustachian tube is normally opened by activities such as swallowing, yawning, and chewing. An inflammation of the tube may keep it closed, and thus fluid builds up in the middle ear. It is often the result of an upper respiratory infection and can be cleared with treatment. Conductive hearing losses are often treatable with either medication or surgery. (Children often have a conductive hearing loss.)
MIXED HEARING LOSS
Mixed Hearing Loss is simply a combination of the above two types of hearing loss. It can occur when a person has a permanent sensorineural hearing loss and then also develops a temporary conductive hearing loss.
Hearing loss can also be the result of damage to the
nervous system through which neural impulses generated by the inner ear pass on
the way to the brain. The most common cause of this type of loss is a tumor
which pinches the nerve. If found in the early stages most of these can be