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How do hearing aids work?

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audiologist inserting hearing aid into childs ear

Hearing aids are a game changer for children and adults alike, letting them improve hearing loss and hear conversation and ambient sounds with greater ease. There are different styles of devices, in many cases giving you options to customize one for your lifestyle.

Whether appearance, price or extra features is your biggest concern, the right hearing aid for you is probably out there somewhere. Keep reading to learn more about how hearing aids work and about the different types and styles available.

Basic components of hearing aids

Hearing aids are small yet powerful devices with complex inner workings that help improve a user's hearing. The first step to understanding how these devices work is learning about their structure and the function of each component.

Hearing aids are made up of a few basic components: a mic, amplifier and speaker.

  • Microphone: The microphone detects sounds around the user. All hearing aids have an omnidirectional microphone, and some have a second directional microphone that focuses on the source of the sound and filters out background noise. These types of mics are great for noisy settings, like for conversations in crowded cafes. Standard directional mics typically focus on sounds in front of the user, while adaptive directional mics can change direction to focus on other speakers or sounds.
  • Amplifier: The amplifier increases the volume of a sound, but — fortunately — this component doesn't amplify just any sound that meets your ears. Your hearing aid will be programmed to amplify only the frequencies you need help hearing.
  • Speaker: The speaker is located on the innermost portion of the hearing aid and lets the device direct the amplified sound into your ear.

While these are the basic components of a hearing aid, several other components come into play. The entire hearing aid is powered by a battery that may be replaceable or rechargeable. The device will also have a program button or volume dial.

If you choose to get a more advanced hearing aid, it will likely have features like a telecoil, Bluetooth capability, a remote control and other accessories. Discuss your options with an audiologist to figure out which is right for you.

How hearing aids work

So, how does a hearing aid actually work? Hearing aids may come with plenty of different bells and whistles, but they typically function the same way.

To break it down into a few simple steps, a hearing aid basically works like this:

  1. When a sound first reaches your ears, the microphone detects it. A computer chip then converts it into a digital signal that contains details about the sound's pitch, volume and location.
  2. The digital signal flows through the amplifier, which strengthens the signal. The amplification is customized to your degree of hearing loss.
  3. The sound moves to the speakers and is projected into your ear at a clear, comfortable volume.

To ensure the hearing aid amplifies sounds to the degree you need, an audiologist will program the device to match your hearing profile.

For example, someone who spends a lot of time in noisy environments can adjust their hearing aid to amplify conversations and soften ambient noise. Before you're fitted with a hearing aid, you'll undergo detailed hearing tests to identify your specific needs.

If you have a Bluetooth-capable hearing aid, it’ll come with a chip that transmits radio waves to compatible devices. These waves are harmless and let your device connect to smartphones, televisions, streaming devices, music players and more. Hearing aids with Bluetooth usually include an app that expands the available features and customizations.

Hearing aids may require maintenance and repairs over their lifetime. Some common issues include a lack of sound, low volume, feedback or distorted sound. Maintenance and repairs can typically be performed at your audiologist's office; in some cases, you may need to send the hearing aid to the manufacturer for a repair.

Many of the top hearing aid companies also offer cleanings, replacement batteries and other accessories. Ask your audiologist about which services they provide and which you'll need to perform yourself — some users may find it difficult to adjust or clean smaller devices.

Find a Hearing Aid partner near you.

    Types of hearing aids

    Most hearing aids function in a similar way, but you’ll see some differences between digital and analog hearing aids. Digital hearing aids are the most common option today.

    • Digital hearing aids: Digital hearing aids convert sounds into digital codes that include information on the pitch, volume and direction of the sound. All this information allows full customization to match your degree of hearing loss.
    • Analog hearing aids: The original hearing aids were analog, meaning they convert sound into electrical rather than digital signals. While this helps amplify sound, it doesn't amplify particular sounds, meaning users tend to get quite a bit of background noise and feedback.

    Digital vs. analog hearing aids

    Digital hearing aids tend to outperform the classic analog style for several reasons:

    • Less background noise and feedback
    • Directional microphones
    • More customization
    • Compatibility with smart devices

    Smartphone and smart TV connection is an important feature for many digital hearing aid wearers. Whether you're streaming music directly to your hearing aid or using an app to track its location if you’ve misplaced it, the convenience factor of a digital hearing aid is pretty significant.

    All major hearing aid providers create digital hearing aids; it's difficult to find high-performing analog hearing aids at this point. Digital hearing aids have plenty of features and customization options to accommodate all types of users.

    Styles of hearing aids

    The style of the hearing aid is where you really get down to matters of preference and comfort. There are several different types to choose from, each with its own pros and cons. Some are more discreet than others but require nimble fingers for any adjustments. Meanwhile, the larger models are more durable and easy to clean.

    Carefully consider each style’s comfort along with your type of hearing loss and physical capabilities. Keep in mind that smaller hearing aids may not be suitable for those with greater hearing needs, as these hearing aids don't have the same power capabilities of larger devices.

    The cost of a set of hearing aids depends on factors including the technology of the device, its features, the style and the manufacturer.


    Behind-the-ear (BTE) aids are larger and fit over the wearer’s ear. The plastic case containing the battery and other components sits behind the ear, and a tube runs over the top to connect to an earmold. BTE hearing aids are great for any age and degree of hearing loss because they provide greater amplification and space for directional microphones.

    Some BTE aids, called mini-BTE aids, or receiver-in-canal hearing aids, have an open fit with only a narrow tube going into the ear canal. Earwax is less likely to build up, and users experience less of a “plugged-up” sensation in their ears. The devices are durable and easy to handle, and they typically include features like rechargeable batteries and volume controls. However, they can pick up wind and other environmental noise, and they’re more noticeable than other types of hearing aids.


    In-the-ear (ITE) hearing aids rest in the outer ear. These devices can often be matched to the wearer’s skin tone, and they’re more discreet than models that fit over the ear. Due to the slightly larger size, ITE aids have a longer battery life, have more area for controls and are easier to handle.

    The size of ITE aids may result in more environmental noise, however, and the devices are also prone to earwax buildup. These aids are best for adults with mild to severe hearing loss.


    In-the-canal (ITC) and completely-in-the-canal (CIC) hearing aids are the smallest, most discreet hearing aid option. These tiny devices fit fully within the ear and may be partially or fully concealed, and they provide protection from excess wind noise. This type is best for adults with mild to moderate hearing loss.

    Features like volume control and second directional microphones are limited on these smaller aids. For those with dexterity limitations, it can be difficult to adjust, remove or clean the devices.

    Bottom line: Are hearing aids right for you?

    The best way to find the right hearing aid is to visit a hearing professional. At an audiologist's office, you can get your hearing tested and find out if a hearing aid can help improve your hearing loss.

    Whether your hearing loss is mild or profound, an audiologist can match you with the right brand and model of hearing aid for your needs, lifestyle and budget. You should then have a trial period to test out your hearing aid and make sure it’s comfortable and easy to use and improves your quality of life.

    For more, compare our picks for invisible hearing aids and hearing aids for tinnitus.

    Article sources
    ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. To learn more about the content on our site, visit our FAQ page.
    1. American Academy of Audiology, “Hearing Aids.” Accessed Oct. 4, 2021.
    2. U.S. Food and Drug Administration (FDA), “How to get Hearing Aids.” Accessed Oct. 4, 2021.
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