Hearing aids - how they work

Most often worn in or behind the ear(s), a hearing aid is a small electronic device. They are used to assist and improve hearing, understanding speech and communication, thus raising the overall quality of life for a person with hearing loss. Regardless of their size or style, all hearing aids consist of the same basic components, which include a microphone, amplifier, receiver and a battery. The parts work together to make sounds clearer and louder to the individual wearing the hearing aid. Following is a breakdown of a hearing aid’s components:

The four key components of a hearing aid


A hearing aid microphone picks up the surrounding environment’s sound and converts the sounds into electrical signals.


The hearing aid’s amplifier increases the overall loudness or power of signals the microphone receives. The sounds are modified by specialized filters and equalizers, allowing only relevant sounds to be amplified for the user.


The hearing aid receiver is also referred to as it’s speaker. Electrical signals from the microphone are converted into acoustic signals that can be heard by the user.


The hearing aid’s power source is the battery. Typically, hearing aids require various sized special batteries. These batteries last between 5 to 14 days on average. The user’s needs and complexity of their listening environments, the specific hearing device, the amount of usage (and more) all contribute to the battery’s life and usage time.

Most hearing aids have the common parts mentioned above. However, as you’ll read below, additional parts are available with different needs and circumstances.

Receiver, amplifier, microphones

Additional parts of hearing aids

There are various sizes and styles that may have additional parts. The hearing aid clinician normally decides what additional parts may be needed, and orders them accordingly. The additional parts are based on the user’s hearing loss, needs, lifestyle, etc. Earmolds, ear hooks, air vents, volume control, memory control, telecoils and wax guards are a few examples of a hearing aid’s available additional parts.

Ear Hook

An ear hook loops over the top of the ear, normally made of clear plastic. The ear hook connects the tubing to the hearing aid. This additional part is only available on Behind-the-Ear (BTE) devices.


Another common additional part is an earmold that is a custom piece worn in the ear. It is attached to the hearing aid and helps contain sound in the user’s ear. An ear mold is custom made from an impression of the user’s ear. You and your hearing professional will decide together if an ear mold is right for you. 


For hearing aids, a vent is simply a hole that runs completely through an ear mold or custom hearing aid. It allows airflow into and out of the ear to prevent infection and assists the user to not feel like they have a “plugged-up ear”.

Battery, earhook, earmold, vent

Wax Guard (ex. Hear Clear)

A wax guard protects the electronic components of the hearing aid by catching ear wax with a small filter. Your hearing healthcare professional will advise you as to how often you should change your wax guard (Hear Clear). Check out our instructional videos to see how to change your Hear Clear wax guards for each hearing aid style.

Volume Control

The volume control is exactly how it sounds; it allows the wearer to adjust the loudness of sounds. The volume control switch or button is not available on all hearing aids and all hearing aid users may not desire this option. 

Memory Control

The user may switch between pre-programmed hearing aid settings for different environments with the memory control option. This may not be available on every style of hearing aid and all users may not desire this option.

Note: many modern hearing aids offer a mobile app (like the Thrive Hearing app on our Livio and Livio AI hearing aids) or wireless accessory to control memory and volume.


Often referred to as a “t-coil”, a telecoil is a small magnetic sensor and is offered in various hearing aids. They allow hearing aids to connect directly to different sound sources, like a public address system or telephone. A t-coil offers sound quality improvements in specific situations. This can sound better than a traditional microphone by allowing the user to hear the desired signal more clearly, especially in situations with background noise.

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

Wax guard, volume & memory, telecoil

For more details on hearing aid technology and which device would be right for you, talk to a local hearing professional! They will ensure you get the right hearing aid for your unique needs, lifestyle and level of hearing loss. To find a professional in your area, call 1-855-970-2990 or click here.

By Starkey Canada