hearing aids

Hearing Aids 101

A hearing aid is a medical device that is worn behind or within the ear canal. Hearing aids can be classified as either prescription, purchased through a hearing professional (audiologist, hearing aid specialist, or ENT); or over-the-counter, hearing aids intended for use by adults (age 18 or over) with mild to moderate hearing loss that may be purchased online, through the mail, or in a retail location without the intervention of a licensed hearing professional.

Hearing aids are built with the same basic parts: the microphone, the processor, the receiver (or loudspeaker), and the battery.


The microphone(s) captures the natural sound surrounding the hearing aid user. Microphones can be either directional, picking up sound in front of the wearer, or omni directional, where sound is captured from every direction. When a microphone captures sound, it is converted to a digital message and sent to the processor.

The processor reads the microphone’s digital message and customizes what is amplified. After programming by a hearing healthcare professional, the processor will be able to enhance speech recognition, amplify certain sounds, cancel feedback and reduce background noise. A hearing aid’s quality is determined by its processing abilities as it is able to be customized to benefit the unique needs of the user.

The receiver/loudspeaker sends a soundwave from the processor to the ear canal. The hearing aid alters sounds in the environment to be clearer and more recognizable by the user. Hearing healthcare professionals are able to fit earpieces comfortably in the user’s ear to further ensure the highest quality of sound.

The battery keeps the hearing aid on and functioning. Depending on the hearing aid style and capabilities, disposable batteries can last anywhere from 3-20 days. Rechargeable batteries were created to provide power throughout the day after an overnight charge. More on batteries is discussed in the battery section.

More information regarding styles of hearing aids can be found at “Types of Hearing Aids


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