You and your hearing instrument specialist should select a hearing aid that best suits your needs and
lifestyle. The hearing aid that will work best for you depends on the kind and severity of your hearing
loss. If you have a hearing loss in both of your ears, two hearing aids are generally recommended
because two aids provide a more natural signal to the brain. Hearing in both ears also will help you
understand speech and locate where the sound is coming from. Price is also a key consideration
because hearing aids range from hundreds to several thousand dollars. Similar to other equipment
purchases, style and features affect cost. However, don’t use price alone to determine the best hearing
aid for you.
A hearing aid will not restore your normal hearing. With practice, however, a hearing aid will increase
your awareness of sounds and their sources. You will want to wear your hearing aid regularly, so
select one that is convenient and easy for you to use. Other features to consider include parts or
services covered by the warranty, estimated schedule and costs for maintenance and repair, and the
hearing aid company’s reputation for quality and customer service.
Hearing aids work differently depending on the electronics used. The two main types of electronics are
analog and digital.
Digital aids convert soundwaves into numerical codes, similar to the binary code of a computer, before
amplifying them. Because the code also includes information about a sound’s pitch or loudness, the
aid can be specially programmed to amplify some frequencies more than others. Digital circuitry gives
a hearing specialist more flexibility in adjusting the aid to a user’s needs and to certain listening
environments. Digital circuitry gives the patient more flexibility by being able to choose from automatic
hearing aids, manual hearing aids or both. These aids also can be programmed to focus on sounds
coming from a specific direction. Background noise is also processed by the hearing instrument. This
makes noisy environments more comfortable for the wearer, and with some models gives the wearer an
improved signal to noise ratio and enables speech to be heard better. Digital circuitry can be used in all
types of hearing aids.
Analog aids convert soundwaves into electrical signals, which are amplified. Analog/adjustable hearing
aids are custom built to meet the needs of each user. The aid is programmed by the manufacturer
according to the specifications recommended by your hearing specialist. Analog/programmable hearing
aids have more than one program or setting. A hearing specialist can program the aid using a
computer, and the user can change the program for different listening environments from a small, quiet
room to a crowded restaurant, to large open areas, such as a theater or stadium.
Analog/programmable circuitry can be used in all types of hearing aids, but many manufacturers are
phasing out this product choice.
There are several basic styles of hearing aids. The styles differ by size, their placement on or inside
the ear, and the degree to which they amplify sound.
• Behind-the-ear (BTE) hearing aids consist of a hard plastic case worn behind the ear and connected
to a plastic earmold that fits inside the outer ear. The electronic parts are held in the case behind the
ear. Sound travels from the hearing aid through the earmold and into the ear. BTE aids are used by
people of all ages for mild to profound hearing loss. The ear mold may be custom made to the ear or
non-custom depending on the degree of hearing loss. All levels of technology can fit into this style.
• Receiver in the canal, also referred to as a receiver in-the-ear instrument. Small, open-fit aids sit
completely behind the ear, with only a narrow tube inserted into the ear canal, enabling the canal to
remain open. In addition, some people may prefer the open-fit hearing aid because their perception of
their voice does not sound “plugged up’ and sounds more natural. All level of technology can fit into this
style, including directional microphones.
• Custom aids are custom made to the shape of your ear. They come in different sizes based upon the
amount of volume necessary for your level of hearing loss. All levels of technology are available in all
sizes but some sizes may be limited in available features based on to the size of the ear.
• In the ear (ITE) hearing aids fit completely inside the outer ear and are used for mild to severe hearing
loss. The case holding the electronic components is made of hard plastic.
• In the canal (ITC) hearing aids fit into the bowl of the ear and are used for mild to moderately severe
• Some ITE and ITC aids may have certain added features installed, such as a telecoil. A telecoil is a
small magnetic coil that allows users to receive sound through the circuitry of the hearing aid, rather
than through its microphone. This makes it easier to hear conversations over the telephone. A telecoil
also helps people hear in public facilities that have installed special sound systems, called induction
loop systems. Induction loop systems can be found in many churches, schools, airports, and
auditoriums. Custom hearing aids are usually not worn by young children because the casings need to
be replaced often as the ear grows.
• Completely-in-canal (CIC) hearing aid is nearly hidden in the ear canal. These are used for mild to
moderately severe hearing loss. Because they are small, CIC aids may be difficult for a person to
adjust and remove. In addition, they have less space available for batteries and additional devices, such
as a telecoil and directional microphone. They usually are not recommended for young children or for
people with severe to profound hearing loss because their reduced size limits their power and volume.
If you think you might have hearing loss and could benefit from a hearing aid, visit a hearing instrument
specialist. A hearing instrument specialist is a hearing health professional who identifies and measures
hearing loss and will perform a hearing test to assess the type and degree of loss. At the appointment,
the hearing Instrument specialist will review your hearing test completely to help you understand what
type of hearing loss is present, and what the options for remediation include. If the identified hearing
loss can be treated medically, an appropriate referral will be made to either a primary care physician or
an otolaryngologist. An otolaryngologist is a physician who specializes in ear, nose, throat disorders
and surgeries and will investigate the cause of the hearing loss.
Do I Have a Hearing Loss? See our webpage on “Knowing the Signs of Hearing Loss”
Hearing aids are primarily useful in improving the hearing and speech comprehension of people who
have hearing loss that results from damage to the small sensory cells in the inner ear, called hair cells.
This type of hearing loss is called sensorineural hearing loss. The damage can occur as a result of
disease, aging, or injury from noise or certain medicines.
A hearing aid magnifies sound vibrations entering the ear. Surviving hair cells detect the larger
vibrations and convert them into neural signals that are passed along to the brain. The greater the
damage to a person’s hair cells, the more severe the hearing loss, and the greater the hearing aid
amplification needed to make up the difference. However, there are practical limits to the amount of
amplification a hearing aid can provide. In addition, if the inner ear is too damaged, even large vibrations
will not be converted into neural signals. In this situation, hearing aid benefit may be limited and
appropriate hearing aid devices may be recommended.
Some individuals with conductive hearing loss (a loss occurring from the middle ear) may also benefit
from hearing aids. Patients with conductive losses who opt not to have surgery often do very well with
A hearing aid is a small electronic device that you wear in or behind your ear. It makes some sounds
louder so that a person with hearing loss can listen, communicate, and participate more fully in daily
activities. A hearing aid can help people hear better in both quiet and noisy situations, and to hear
sounds that they have been missing.
A hearing aid has three basic parts: a microphone, amplifier, and speaker. The hearing aid receives
sound through a microphone, which converts the sound waves to electrical signals and sends them to
an amplifier. The amplifier increases the power of the signals and then sends them to the ear through a
speaker. Most modern hearing aids contain digital technology. Please see “Do all hearing aids work
the same way?” for a discussion on digital versus analog aids.