To understand hearing loss requires a basic understanding of how we hear. Your outer ear acts like a dish that collects sound waves. These sound waves travel along the ear canal and vibrate against the ear drum. In the middle ear, three tiny bones (the smallest in the body) transfer vibrations to the fluid-filled cochlea in the inner ear.
This creates ripples in the fluid, which bend the hair cells in the cochlea. This movement, in turn, is converted into electrical impulses that are carried through the auditory nerve to the brain, where they are translated into meaningful information. Hearing is a complex process. As with any such process, things can go wrong.
The most common types of hearing loss are:
Sensorineural loss – the most common type (95%) of hearing loss, occurs when the nerve endings in the inner ear are not transmitting sound properly as a result of damage to the hair cells in the cochlea. This damage can be caused by a number of things including noise or a natural deterioration of the hair cells that comes with age. Sensorineural loss cannot be cured medically but it can usually be improved through the use of hearing instruments.
Conductive loss – occurs when sound is not being sent properly to the inner ear due to some ‘mechanical’ problem. Conductive loss is often the result of damage or blockage in the middle ear. In most cases, conductive hearing problems can be corrected medically.