While there are three different types of hearing loss; Conductive, Sensorineural and mixed, they can be caused by many different things.
Conductive Hearing loss
A conductive hearing loss means the ear system has difficulty in conducting the sound waves into the cochlea. It can be from the outer ear or within the middle ear.
Disfigurement, loss or an ear birth defect is an obvious conductive hearing loss. Our ears are shaped to capture sound waves and funnel them into the ear canal. If this part of our anatomy is missing or damaged then the sound waves are not trapped and funnelled effectively.
Blockage of the ear canal obstructs the passage of sound waves. A simply cause of a blockage is the build up of wax or other foreign body. While generally this is temporary, if left the wax can harden and become difficult to remove. The ear drum and canal beyond the blockage can become inflamed and this may result in permanent hearing loss if not treated. Other causes are inflammation, disease or tumours in the ear canal tissues and middle ear.
A common condition of the middle ear is known as ‘glue ear’. This is when the fluid in the middle ear becomes thickened and the small bones (ossicles) do not move as they should. The treatment is usually the insertion of grommet into the ear drum to allow the ‘glue’ to drain.
A perforated ear drum also causes poor conduction of the sound waves. This can sometimes be repaired through surgery.
Calcification of the middle ear (otosclerosis) is when calcium builds up in and around the small bones, so they can no longer move with sound vibration. Sometimes surgery can help this condition.
Sensorineural Hearing loss
A sensorineural hearing loss is sometimes called nerve deafness because the small hairs (nerves) in the cochlea die away. This means the connection between the middle ear and the auditory nerve is lost making it impossible for the sound (electrical impulses) to be conveyed to the brain. Once these hairs die there is no way of rejuvenating them and the hearing loss is permanent.
There are many causes of a sensorineural hearing loss from childhood diseases such as mumps or measles, to exposure to loud noise, meningitis, trauma (head injuries) or tumours.
The treatment differs depending on what has caused the loss, but the hearing loss is permanent and only a cochlea implant can help restore a sense of sound.
Mixed hearing loss
A mixed hearing loss is when the damage involves the outer/middle, inner ears and/or auditory nerve. It is hard to treat because it requires more than one kind of intervention. Once again hearing loss is permanent and only a cochlea implant can help restore a sense of sound.
If someone has a hearing loss it is important to get it assess by hearing professionals to determine the cause of the loss and whether anything can be done to restore it or stall further losses.