What's the difference? CONDUCTIVE DEAFNESS AND NERVE DEAFNESS.
Byline: DR MIRIAM STOPPARD
For sound to reach the inner ear it has to travel through the external ear canal, cross the middle ear, and enter the hearing organ (the cochlea) in the inner ear. Anything that gets in the way and blocks this conduction of sound will cause deafness.
The most common blockage is ear wax which can easily be dissolved or syringed out. The second most common cause in adults is a form of arthritis which affects the chain of three bones that carry sound waves across the middle ear to the inner ear.
Because the hearing organ in the inner ear is intact, hearing aids, which amplify sound, are very helpful.
NERVE DEAFNESS In nerve deafness the outer and middle ears work well, but the hearing organ in the inner ear is faulty, possibly due to prolonged exposure to loud noise, Meniere's disease and to some viral infections and drugs.
Damage to the acoustic nerve, which carries sound impulses from the cochlea to the brain, may be the result of a benign tumour on the nerve, an acoustic neuroma. As the neuroma enlarges, the deafness will increase.
The treatment for nerve deafness is a cochlea (inner ear) implant.