How Do Hearing Aids Work?

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The ability to hear clearly is an essential part of communicating with family, friends, and others. When we experience hearing loss, our quality of life may be significantly impacted. According to the Centers for Disease Control and Prevention (CDC), more people have hearing loss than diabetes, cancer, or vision trouble.1

Small but mighty, hearing aids improve your hearing by amplifying sounds. However, not all hearing aids are the same. In this article, we'll cover how hearing aids work and what levels of hearing loss may require a hearing aid.

Our editor's grandma wearing her freshly cleaned BTE devices. You can barely see them!

Our editor’s grandma wearing her freshly cleaned BTE devices. You can barely see them!

How Do Hearing Aids Work?

Hearing aids are battery-powered electronic devices worn in or behind the ear to improve the quality of hearing for an individual with hearing loss. Hearing aids work by amplifying sound through a three-part system:1

  1. The microphone detects sound and converts it into an electronic or digital signal. In addition to the microphones, many hearing aids can receive sound via wireless streaming (like Bluetooth) or via an electromagnetic receiver called a telecoil.
  2. The amplifier increases the strength of the signal. It also shares the amount of amplification to match your hearing loss.
  3. The speaker produces the amplified sound into the ear.


Do All Hearing Aids Work the Same Way?

There are two types of hearing aids: digital and analog. While both digital and analog hearing aids contain a microphone, processor (inner circuitry), speaker, and batteries, they do not work the same way to improve hearing loss. The major difference between digital and analog is how the hearing aid amplifies the sound.

Unboxing the Beltone Amaze hearing aids

Unboxing the Beltone Amaze hearing aids

Digital Hearing Aids

Digital hearing aids are powerful minicomputers for the ear. These complex devices treat hearing loss by converting sound waves into codes. Each unique code includes details on the location, pitch, and loudness of the sound coming into the ear. Digital hearing aids provide wearers with greater control to hear the sounds they want (like conversations) and quiet the sounds they don't want to hear (like environmental noises). These are some of the benefits of digital hearing aids:

  • They reduce distracting background noise through a digital sound processor (not found in analog hearing aids).
  • They reduce disruptive feedback such as high-pitched whistling sounds.
  • They assist in focusing on speech versus ambient noise using automatic or manual directional microphone settings.
  • They deliver high-tech pairing with a smartphone or smart TV through Bluetooth or other wireless protocol connectivity (on some models).
  • They provide a greater capability to fine-tune hearing aid settings to meet the individual's specific needs.

Pro Tip: Many popular hearing aids are connected to smartphone apps that include a “Find My Hearing Aid” feature. Turn on this smartphone feature and you'll be able to estimate the location of your hearing aids on a map if you misplace them.

Analog Hearing Aids

Analog hearing aids are the original hearing aid. When it detects a sound, the analog hearing aid converts the sound waves into amplified electrical signals (as opposed to digital signals). An analog hearing aid amplifies all sound, including bothersome background noise.

With the advancement in hearing aid technology and digital hearing aid options, the demand for analog hearing aids is on the decline. Currently, there are no analog hearing aids being developed, sold, or supported by major manufacturers. There are some analog amplifiers and personal sound amplification products (PSAPs) available from smaller companies, but in general, it is less expensive to develop digital devices, so this is the trend. We will likely see fewer and fewer analog hearing devices in the future.

Can Deaf People Hear With Hearing Aids?

For individuals with hearing loss, the level of deafness plays a major part in determining the hearing aids best suited for their needs. Hearing aids may be useful for those with profound hearing loss, which can also be considered deafness. For example, Eargo is an excellent option for moderate high-frequency hearing loss. Phonak or Widex hearing aids are best for profound hearing loss.

Older adults who depend on visual communication (lip reading or sign language) may benefit from a cochlear implant. It's important to note that anyone who can hear well enough with hearing aids is not a good candidate for cochlear implants.3 Cochlear implants are completely different from hearing aids and best for individuals diagnosed with profound hearing loss or deafness. A cochlear implant has two parts: one sits behind the ear and the second portion is surgically placed under the skin.

Did You Know: Learning to care for your hearing aids is an essential part of optimizing your hearing. Find out how often you should clean your hearing aids, the tools needed, and what you should never use when taking care of your devices.

Watch my interview with Editor-in-Chief, Jeff Hoyt, to learn more about the differences between cochlear implants and hearing aids.

What Level of Hearing Loss Requires a Hearing Aid?

As the American Speech-Language-Hearing Association (ASHA) says, not all hearing loss is equal. ASHA determines the degree of hearing loss based on the decibel (dB) needed to properly hear the sounds. For example, the “normal” hearing threshold falls between -10 and 15 dB. If you can only hear sounds at 60 dB, you fall into the category of moderately severe hearing loss.

Eargo App Bass and Treble

Eargo App Bass and Treble

Harvard Health Publishing notes that if the softest sounds you can hear begin at 30 dB or louder, you may be missing a significant portion of what is said to you. This hearing loss makes you a likely candidate for a hearing aid.4

Your first step in understanding your level of hearing loss and whether you need hearing aids is to visit an audiologist or licensed hearing instrument specialist. These professionals are trained and licensed to determine if hearing aids are appropriate for you. If your hearing loss is due to a condition that may be resolved medically, these professionals will refer you to an otolaryngologist (ear, nose, and throat physician).

Learn what to expect during your first audiologist appointment in the video below, featuring audiologist Brad Ingrao.

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Reviewed By

Jeff Hoyt

Editor in Chief

Since graduating from Harvard with an honors degree in Statistics, Jeff has been creating content in print, online, and on television. Much of his work has been dedicated to informing seniors on how to live better lives. As Editor-in-Chief of the personal… Learn More About Jeff Hoyt

Written By

Brad Ingrao


As a practicing audiologist since the 1990’s, Brad Ingrao, AuD has fitted thousands of hearing aids to seniors and people of all ages. Brad is the Official Audiologist for the International Committee on Sports for the Deaf and a well-known speaker. Dr…. Learn More About Brad Ingrao

  1. CDC. (2016). Measuring the Impact of Hearing Loss on Quality of Life.

  2. NIDCD. (2021). Hearing Aids.

  3. Medline Plus. (2021). Cochlear implant.

  4. Harvard Health Publishing. (2017). Now hear this: You may need hearing aids.