Oticon

Your Hearing Illuminated
The ears and the brain work together as a system to organize your world of sound. Picking up the sound starts with both your ears. Being familiar with how the ear works will better prepare you for your visit to the hearing health care specialist and understanding your options - particularly if two hearing devices are recommended.

How Sounds Travel Through the Ear
The anatomy of the ear is precisely shaped to capture sound waves and amplify them. When sound waves enter the ear they follow what might seem like a long and arduous path. But every 'station' has a precise function. This is how it works:

	Sound waves are picked up by the outer ear, which is made up of the pinna and the ear canal.
	Sound is channeled to the eardrum, which vibrates when the sound waves touch it.
	The vibrations are picked up by three tiny bones known as the hammer, anvil and stirrup, which create a bridge from the eardrum to the inner ear.
	The vibrations move on to the cochlea - a spiral-shaped capsule housing a system of fluid-filled tubes.
	When the sound waves reach the fluid it begins to move, setting thousands of tiny hair cells in motion.
	The movements of the hair cells are transformed into electric impulses that travel along the auditory nerve to the brain itself.
	The brain decodes and interprets the electronic impulses, turning a stream of speech into separate, recognizable words.

Types of Hearing Loss
When sound is stopped for whatever reason the brain can no longer process the information accurately. Sound can be muffled, softer, even distorted. Hearing loss can be temporary, medically treated, or progressive. Understanding the nature of the loss will better prepare you for your options.

This type of hearing loss is caused by problems in the ear canal and/or the structures in the middle ear. It occurs when sounds from the outside world cannot be transmitted normally through the ear canal and/or middle ear to the inner ear.

The most common causes of conductive hearing loss can be a buildup of wax in the ear canal, perforated eardrums, fluid in the middle ear (common in children), or damaged or effective ossicles (middle ear bones).

A person with conductive hearing loss may notice their ears seem to be full or plugged. Most conductive hearing losses can be medically or surgically treated. If, for some reason, the hearing loss cannot be corrected, hearing instruments can provide benefit.

This type of hearing loss is the most common type of hearing loss. More than 90 percent of all hearing instrument wearers have sensorineural hearing loss.

It results from a combination of problems in the inner ear and the auditory nerve. They then become unable to convert sound vibrations into the electrical signals needed by the auditory nerve.

The nerve pathways in the auditory nerve itself can also become damaged, preventing the signals from reaching the brain. Although this damage can be caused by exposure to loud noise - through working in a noisy environment for too long - the primary reason is aging.

People with sensorineural hearing loss typically report they can hear people speak, but can't understand what they're saying. Hearing instruments and assistive devices can help.

This kind of hearing loss is caused by a combination of problems in the middle and the inner ear or the auditory nerve. For example, the person may have a noise induced hearing loss from noise exposure and a perforation in the eardrum. The combination of sensorineural and conductive hearing therefore the loss is mixed.

Causes of Hearing Loss
If you have a hearing loss, you may wonder what caused it. It is often not possible to determine a cause with high certainty. Your history and the results of your hearing evaluation will help provide information.

The most common type of hearing loss is called presbycusis, or age induced hearing loss. This is caused by a gradual deterioration of hair cells, which is part of the normal aging process. The degree to which hair cell loss occurs varies from one individual to another.

Some people experience a significant loss of sensory cells at the age of 50, while others only have a negligible loss even at the age of 80. Hearing problems associated with presbycusis can be significantly reduced with the right hearing device.

Another, less common type of hearing loss is noise induced, arising from an acoustic trauma or from exposure to excessive noise for extended periods of time. This causes damage to both the inner and outer hair cells of the cochlea. People with noise-induced hearing loss typically have difficulty hearing high frequency sounds, but hear quite well in the low frequencies. Hearing devices are ideal solutions for noise induced hearing loss.

Types of Hearing Loss and Causes