Your hearing aid’s
parts and controls

Every hearing aid has four key components. See what they are and learn about other common parts and controls.

A hearing aid is a small electronic device that is worn in or behind the ear(s) to assist with and improve hearing, speech understanding, communication, and overall quality of life. All hearing aids, regardless of style or size, have four basic components. Together, they make sounds louder and clearer for the wearer.


The hearing aid microphone picks up sounds from the surrounding environment and converts them into electrical signals.


The hearing aid amplifier increases the overall power or loudness of the signals received from the microphone. Intricate computerized components modify the sounds, so that only those relevant for the user are amplified.


The receiver — also known as the speaker — converts the electrical signals from the microphone into acoustic signals heard by the wearer.


The battery serves as the power source for hearing aids. Whether rechargeable batteries or disposable zinc-air, a hearing aid must have power to operate.

Select a style

Learn more about each style's specific parts and controls.

Additional parts and controls

Depending on the size and style, some hearing aids may have additional parts and controls. These are typically decided upon and ordered with the hearing professional, based on the user’s lifestyle, needs, hearing loss, etc.

Volume Control

This allows the user to adjust the loudness of sounds. This is not available on all styles of hearing aids, and may not be desirable for all hearing aid users.

Memory Control

A memory control allows the user to switch between memories that have been pre-programmed into the hearing aids for a variety of environments. This feature is also not available on all styles of hearing aids, and may not be desirable for all hearing aid users.

Ear Hook

This is a clear plastic attachment that connects to the device and loops over the top of the ear. The ear hook attaches the hearing aid to the tubing. This part can only be found on Behind-The-Ear (BTE) devices.


An earmold is a custom in-the-ear piece that is attached to the hearing aid in order to help contain the sound within the wearer’s ear. A custom earmold is made from an impression of the ear, taken by the hearing professional. Whether someone needs an earmold is a decision best made with your hearing professional.


This is a hole that goes all the way through a custom hearing aid or earmold. It allows for airflow in and out of the ear to help prevent infection and the feeling of a plugged-up ear.

Wax Guard

A wax guard is a small filter that catches the earwax, preventing it from getting into the electronic components of the hearing aid.


A telecoil (sometimes called a t-coil) is a small magnetic sensor offered in some hearing aids. T-coils allow hearing aids to directly connect to different sound sources, like a telephone or public address system. In some specific situations, a t-coil offers sound quality improvements over a traditional microphone allowing the hearing aid user to hear the desired signal more easily, particularly environments with background noise.

In properly equipped venues, t-coils can permit a hearing aid to act as a personal loudspeaker for a public sound system.

Your hearing professional will ensure you get the right hearing aid for your needs.