About Hearing Loss
HOW WE HEAR - 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 sound into separate recognizable words.
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 the information. However, the two most common causes of hearing loss are age-induced hearing loss and noise-induced hearing loss.
Age-induced hearing loss
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.
Noise-induced hearing loss
Another, less common type of hearing loss is noise induced, arising from an 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 aids are ideal solutions for the noise-induced hearing loss.
TYPES OF HEARING LOSS
In general, there are three types of hearing loss: Conductive Hearing Loss, Sensorineural Hearing Loss and Mixed Hearing Loss.
Conductive Hearing Loss
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 can not 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 defective 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 can not be corrected, hearing aids can provide benefit.
Sensorineural Hearing Loss
This type of hearing loss is the most common type of 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.
People with sensorineural hearing loss typically report they can hear people speak, but can’t understand what they’re saying. People with sensorineural hearing loss often complain “everyone mumbles”. Usually, there is no medical way to correct this but hearing aids and assistive devices often help.
Mixed Hearing Loss
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 loss is therefore, mixed.
Have you had your hearing checked lately? Find out how you hear. Call us at (985) 446-8328 for a complimentary hearing screening. Our friendly and knowledgeable staff will be happy to assist you.