The inside mechanisms of hearing aids vary among devices, even if they are the same style. Three types of circuitry, or electronics, are used:
Analog/Adjustable: The hearing aid dispenser determines the volume and other specifications you need in your hearing aid, and then a laboratory builds the aid to meet those specifications. The hearing aid dispenser retains some flexibility to make adjustments. This type of circuitry is generally the least expensive.
Analog/Programmable: The hearing aid dispenser uses a computer to program your hearing aid. The circuitry of analog/programmable hearing aids will accommodate more than one program or setting. If the aid is equipped with a remote control device, the wearer can change the program to accommodate a given listening environment. Analog/programmable circuitry can be used in all types of hearing aids.
Digital/Programmable: The hearing aid dispenser programs the hearing aid with a computer and can adjust the sound quality and response time on an individual basis. Digital hearing aids use a microphone, receiver, battery, and computer chip. Digital circuitry provides the most flexibility for the hearing instrument specialist / audiologist to make adjustments for the hearing aid. Digital circuitry can be used in all types of hearing aids and is typically the most expensive.
A hearing aid is an electronic device with a small microphone that amplifies weak sounds through a small speaker. You must have some ability to hear for the device to work. And because hearing loss affects people in different ways, you need to get the right device for you.
There are several types of hearing aids. Each type offers different advantages, depending on its design, levels of amplification, and size. Before purchasing any hearing aid, ask whether it has a warranty that will allow you to try it out. Most manufacturers allow a 30 day trial period during which aids can be returned for a refund.
There are four basic styles of hearing aids for people with sensorineural hearing loss:
In-the-Ear (ITE) hearing aids fit completely in the outer ear and are used for mild to severe hearing loss. The case, which holds the components, is made of hard plastic. ITE aids can accommodate added technical mechanisms such as a telecoil, a small magnetic coil contained in the hearing aid that improves sound transmission during telephone calls. ITE aids can be damaged by earwax and ear drainage, and their small size can cause adjustment problems and feedback. They are not usually worn by children because the casings need to be replaced as the ear grows.
Behind-the-Ear (BTE) hearing aids are worn behind the ear and are connected to a plastic earmold that fits inside the outer ear. The components are held in a case behind the ear. Sound travels through the earmold into the ear. BTE aids are used by people of all ages for mild to profound hearing loss. Poorly fitting BTE earmolds may cause feedback, a whistle sound caused by the fit of the hearing aid or by buildup of earwax or fluid.
Canal Aids fit into the ear canal and are available in two sizes. The In-the-Canal (ITC) hearing aid is customized to fit the size and shape of the ear canal and is used for mild or moderately severe hearing loss. A Completely-in-Canal (CIC) hearing aid is largely concealed in the ear canal and is used for mild to moderately severe hearing loss. Because of their small size, canal aids may be difficult for the user to adjust and remove, and may not be able to hold additional devices, such as a telecoil. Canal aids can also be damaged by earwax and ear drainage. They are not typically recommended for children.
Body Aids are used by people with profound hearing loss. The aid is attached to a belt or a pocket and connected to the ear by a wire. Because of its large size, it is able to incorporate many signal processing options, but it is usually used only when other types of aids cannot be used.
Using hearing aids successfully takes time and patience. Hearing aids will not restore normal hearing or eliminate background noise. Adjusting to a hearing aid is a gradual process that involves learning to listen in a variety of environments and becoming accustomed to hearing different sounds. Try to become familiar with hearing aids under non stressful circumstances a few hours at a time. Programs are available to help users master new listening techniques and develop skills to manage hearing loss. Contact your hearing aid dispenser for further information about programs that may suit your individual needs.
What problems might I experience while adjusting to my hearing aids?
Become familiar with your hearing aid. Your hearing aid dispenser will teach you to use and care for your hearing aids. Also, be sure to practice putting in and taking out the aids, adjusting volume control, cleaning, identifying right and left aids, and replacing the batteries with the hearing aid dispenser present.
The hearing aids may be uncomfortable. Ask the hearing aid dispenser how long you should wear your hearing aids during the adjustment period. Also, ask how to test them in situations where you have problems hearing, and how to adjust the volume and/or program for sounds that are too loud or too soft.
Your own voice may sound too loud. This is called the occlusion effect and is very common for new hearing aid users. Your hearing aid dispenser may or may not be able to correct this problem; however, most people get used to it over time.
Your hearing aid may "whistle". When this happens, you are experiencing feedback, which is caused by the fit of the hearing aid or by the buildup of earwax or fluid. See your hearing aid dispenser for adjustments.
You may hear background noise. Keep in mind that a hearing aid does not completely separate the sounds you want to hear from the ones you do not want to hear, but there may also be a problem with the hearing aid. Discuss this with your hearing aid dispenser.
Medically, there are two major types of hearing loss. Conductive hearing loss involves the outer and middle ear. It usually results from a wax blockage, a punctured eardrum, birth defects, ear infections, or it may be genetic. Conductive hearing loss generally can be corrected surgically.
Sensorineural—or "nerve"—hearing loss involves damage to the inner ear. It can be caused by aging, prenatal and birth-related problems, viral and bacterial infections, genetics, trauma (such as a severe blow to the head), exposure to loud noises, the use of certain drugs, or fluid buildup or a benign tumor in the inner ear. Sensorineural hearing loss usually can't be repaired surgically; it's usually corrected with a hearing aid.
