There are two main types of hearing loss: conductive hearing loss and sensorineural hearing loss. Sensorineural hearing loss is commonly referred to as nerve deafness. It occurs when the tiny hair cells in the inner ear, the auditory nerve or the brain are damaged.
A sensorineural hearing loss is permanent. Conductive hearing loss is the result of improper sound transmission through the ear canal to the eardrum and tiny bones in the middle ear. A person with conductive hearing loss has a problem with hearing sounds whereas someone with sensorineural hearing loss has difficulty distinguishing the sounds so that pin may sound like fin or peach may be heard as teach.
Sometimes a patient will have both a conductive loss and a sensorineural loss. When this occurs it is referred to as a mixed hearing loss. Another type of hearing loss is presbycusis or age related hearing loss. Presbycusis can begin as early as age 40. It is progressive and affects the person s ability to hear high frequency sounds. Sensorineural hearing loss results from damage to the tiny hair cells in the cochlea or to the eighth cranial nerve. This usually occurs because of prolonged exposure to loud noise. It is also hereditary. However it can be caused by an infection, disease, injury or toxic drugs.
Conductive hearing loss usually results from damage to the ossicles (tiny bones of the middle ear), the eardrum or the ear canal. It can also be caused by infection, a cholesteatoma, otosclerosis, or a build up of earwax. Physicians used various tests to determine what type of hearing loss one has and the extent of the loss. The treatment will depend upon the cause of the loss. Infections are normally treated by antibiotics although sometimes a myringotomy will be required. This is a procedure that involves making a tiny opening in the eardrum to relieve the pressure caused by an infection.
Certain hearing losses such as presbycusis are permanent. In this case the patient will need to be fitted with a hearing aid in one and sometimes both ears. Hearing aids amplify the sounds and transmit it to the ear canal. People with conductive hearing loss and with presbycusis respond well to the use of hearing aids, as all they require is an increase in volume. However, people with sensorineual hearing loss have a more serious problem. Their difficulty is not just in volume but also in distinguishing the different speech sounds. So even though a hearing aid amplifies the word peach it may still be interpreted as teach by a person with a sensorineural loss.
They will need more sophisticated hearing aids to help them distinguish sounds. They also have more difficulty using the telephone and listening to TV.
When a hearing loss becomes severe it is possible to have a cochlear implant. A cochlear implant is particularly helpful for the person with severe sensorineural hearing loss. It will not restore normal hearing but it is effective enough to enable the person to better discriminate sounds. When supplemented with lip reading it can improve communication skills. However, the person who has undergone a cochlear implant will need to work with a therapist to learn to interpret the sounds they hear.