Hearing is a complex process that involves your ear, nerves, and brain. A hearing impairment or loss may result if any of the structures are disrupted. Fortunately, hearing aids can help people with certain types of hearing loss hear, communicate, and lead active lives.
Your outer ear, the part that you can see, collects the sound waves. The sound waves travel through the ear canal to the middle ear, which is located inside of your head. Sound waves cause the eardrum (tympanic membrane) to vibrate, which in turn cause the three tiny bones (malleus, incus, stapes) in your ear to move. Their movements cause vibrations that are detected by the cochlea in the inner ear. The cochlea is a structure that contains liquid and tiny hair cells. Some of the hair cells make the vibrations louder and others send nerve signals to your brain that are interpreted as sound.
Sensorineural hearing loss is a type of disorder that results from problems with hair cells in the inner ear. Hearing aids are small electronic devices that can help people with sensorineural hearing loss. A hearing aid is worn in or near the ear. It makes sounds and vibrations that enter the ear stronger. The damaged structures in the inner ear are able to detect the magnified vibrations and in turn, send nerve signals to the brain. The degree of hearing aid amplification that is needed correlates with the amount of damage to the inner ear and subsequent hearing loss.
There are several different types of hearing aids to choose from. The type of hearing aid that you need depends on the amount of hearing loss that you have. Some hearing aids are more appropriate for adults than children. Traditional hearing aids are removable. Newer models can be surgically implanted in the ear. Hearing aids differ greatly in size, style, and cost. Your doctor will help you select the most appropriate one for you. Removable hearing aids are categorized as:
Behind-the-ear (BTE) Hearing Aids
Behind-the-ear (BTE) hearing aids consist of a component that is worn behind the ear and a earmold that fits inside of the outer ear. The hearing aid is made of hard plastic. BTE hearing aids are most appropriate for people with mild to profound hearing loss. Newer open-fit BTE hearing aids have a small component that is worn behind the ear and a tube that is inserted into the ear canal. An open-fit BTE is helpful for people that experience earwax buildup.
In-the-ear (ITE) Hearing Aids
In-the-ear (ITE) hearing aids are placed inside the outer ear. They may include a telecoil that helps with hearing telephone conversations. ITE hearing aids are most appropriate for adults with mild to severe hearing loss.
Canal Hearing Aids
In-the-canal (ITC) hearing aids are custom made to fit inside the ear canal. Completely-in-canal (CIC) hearing aids are inside the ear canal and virtually hidden. Canal hearing aids are most appropriate for adults with mild to moderately severe hearing loss.
Surgically Implanted Hearing Aids include:
Middle Ear Implant (MEI) A middle ear implant (MEI) is a device that is surgically attached to the bones in the middle ear. The MEI causes the bones to move and send greater vibrations to the inner ear structures.
Bone-Anchored Hearing Aid (BAHA) The bone-anchored hearing aid (BAHA) is surgically attached to the bone behind the ear. The BAHA transmits amplified vibrations to the inner ear structures.