The Comprehensive Guide to Hearing Aids

The Comprehensive Guide to Hearing Aids

Hearing aids are transformative devices that can improve the quality of life for individuals experiencing varying degrees of hearing loss. Whether you're a potential user, a caregiver, or a medical professional, this comprehensive guide is designed to provide in-depth knowledge about hearing aids and their role in improving auditory health.

Understanding Hearing Aids

Hearing aids, essentially miniature amplifying devices, function by capturing, amplifying, and delivering sounds to the ear. This process facilitates improved auditory experiences, particularly for individuals who suffer from hearing loss. A typical hearing aid consists of three core components:

  • Microphone: Captures surrounding sounds and converts them into electrical signals.

  • Amplifier: Boosts the strength of these signals.

  • Speaker (or receiver): Delivers the amplified signals into the ear.

Out with Analog technology and in with Digital Signal Processing

Hearing aids aim to enhance auditory perception in various settings, from quiet, intimate gatherings to noisy, crowded environments. However, it's worth noting that despite their benefits, only approximately one in five individuals who could benefit from hearing aids actually make use of them.

Hearing aids used analog technology many years ago. For well over 15 years now, almost all hearing aids manufactured today use digital signal processing. As evidenced from the illustrations below, DSPs far outweigh analog technology in fidelity, processing power, intelligibility of speech and improving performance in noise.

Modern digital hearing aid circuitry

By converting the incoming signals into computerized ‘bits,’ they can be processed, or manipulated extremely fast and efficiently in many complex ways using mathematical formulas known as algorithms. This gives digital signal processors (DSP) tremendous speed and agility to recognize sound’s key ingredients. Like a graphic equalizer in high-end audio systems, algorithms can continually divide sounds into frequency channels. They help preserve and emphasize the higher frequencies containing vital consonant sounds in speech – the “c” and “t” sounds in “cat” – over the distracting rumble of low frequency noise.

That same sensitivity is also useful in quiet surroundings. Utilizing an audio technique called expansion, the digital algorithm senses the consistency of softer environmental sounds from ventilation systems and appliances. It automatically reduces amplification in the appropriate frequency range, immediately restoring proper levels when the sound pattern changes.

The precision and flexibility of digital technology also gives your hearing professional the ability to tailor your amplification more accurately for the best possible match to your listening and lifestyle needs. This process may include subsequent visits to ensure that you are receiving maximum benefit from your instruments.

Modern custom hearing aids are made using a precision laser scanning system and advanced stereolithography manufacturing processes. Here is an image of how hearing professionals at Key Hearing Aids fulfill orders for custom hearing aids through our manufacturing partners.

Manufactured using laser impression

The Impact of Hearing Aids

Hearing aids primarily aid in enhancing the hearing and speech comprehension of individuals facing sensorineural hearing loss. This form of hearing loss is often caused by damage to the hair cells in the inner ear, due to aging, disease, excessive noise exposure, or certain medications.

Hearing aids function by magnifying sound vibrations entering the ear. The surviving hair cells detect these larger vibrations and convert them into neural signals that are then sent to the brain. The degree of hearing loss is directly correlated to the extent of hair cell damage – the greater the damage, the more severe the hearing loss, and the higher the amplification required.

Consultation for Hearing Loss

If you or a loved one have concerns or questions about hearing loss, there are several options available. Over-the-counter (OTC) hearing aids have emerged as a new category of hearing aids that can be purchased directly without the need for a professional hearing health examination. These devices are designed to assist adults with mild to moderate perceived hearing loss.

Prescription hearing aids, on the other hand, are available from a hearing health professional who will program them for your specific degree of hearing loss. These hearing aids or other devices may be necessary for more significant or complex hearing loss conditions.

Various Styles of Hearing Aids

Hearing aids come in six different form factors and in some specialized designs

There are six primary styles of hearing aids, each differing in size, placement in or on the ear, and degree of sound amplification. The styles include:

Behind-the-ear (BTE): Behind-the-ear (BTE) devices are appropriate for people with a wide range of hearing loss, from mild to profound. This device fits neatly behind your ear. The body of the hearing aid attaches to a custom ear mold or thin tubing. Because this device has several parts, manual dexterity is necessary to ensure proper insertion and placement.

Behind-the-Ear (BTE)

Receiver-in-the-ear (RITE): Receiver-in-the-ear (RITE) hearing aids are similar to BTE devices. The body of a RITE hearing aid sits behind your ear. A thin receiver wire extends from the body of the hearing aid over your outer ear and into your ear canal. A soft tip sits just inside of your ear canal without sealing it. For many people, this offers a more natural sound. RITE devices require manual dexterity. They’re appropriate for mild to severe hearing loss.

Receiver-in-the-Ear (RITE)

In-the-ear (ITE): These devices fill either your entire ear (full-shell) or a portion of the bowl (half-shell) of your ear. These are best for people who may have dexterity issues or difficulty handling small items. Providers often recommend ITE devices for people with moderate to severe hearing loss.

In-the-Ear (ITE)

In-the-canal (ITC): These hearing aids fit more deeply into your ear canal than ITE hearing aids, making them less visible. Because of their smaller size, they use smaller batteries and may be more difficult to handle. Depending on your situation, you may even qualify for completely-in-the-canal (CIC) hearing aids. These devices fit deeper into the ear canal so they’re even less visible.

In-the-Canal (ITC)

Completely-in-the-canal (CIC): These are seated deeply within the ear canal, making them cosmetically desirable for some users.

Completely-in-the-Canal (CIC)

CROS/BiCROS: Your healthcare provider may recommend a CROS/BiCROS hearing aid if you have normal hearing or minimal hearing loss in one ear, and very little or no usable hearing in the other ear. You wear the hearing aid on the better hearing side, and you wear an additional microphone on the poorer hearing side. This allows you to hear from the poorer side — even though it delivers all sounds to your better ear. These devices are especially beneficial when someone is talking on the side of the poorer ear. CROS stands for “Contralateral Routing of Signals.” BiCROS stands for “Bilateral Contralateral Routing of Signals.”


Each style caters to different requirements and degrees of hearing loss, and your healthcare professional can guide you in selecting the most suitable option based on your needs.

Choosing the Right Hearing Aid

Choosing the right hearing aid depends on the nature and severity of your hearing loss. If you have a hearing loss in both ears, two hearing aids are generally recommended as they provide a more natural signal to the brain. You and your hearing professional should select a hearing aid that best suits your needs and lifestyle. Factors to consider include the warranty, maintenance and repair costs, upgrade opportunities, and the hearing aid company’s reputation for quality and customer service.

Important Questions to Ask Before Purchasing a Hearing Aid

Before purchasing a hearing aid, ensure you ask your hearing professional the following questions:

  1. Which features would be most beneficial to me?

  2. What is the total cost of the hearing aid, and do the benefits of newer technologies justify the higher costs?

  3. Is there a moneyback guarantee period?

  4. What fees are non-refundable if the aids are returned?

  5. How long is the warranty, and can it be extended?

  6. Does the warranty cover future maintenance and repairs?

Adjusting to Your Hearing Aid

Adjusting to a hearing aid requires time and patience. Regular usage, becoming familiar with the hearing aid’s features, and practicing how to adjust the volume and program for different sound levels are key to getting comfortable with your new device.

Caring for Your Hearing Aid

Proper maintenance and care are crucial to extend the life of your hearing aid. This includes keeping the hearing aids away from heat and moisture, cleaning them as instructed, avoiding the use of hair care products while wearing them, turning them off when not in use, and replacing dead batteries immediately.

Purchasing Hearing Aids Over the Counter

As of August 16, 2022, the U.S. Food and Drug Administration (FDA) has approved a new category for over-the-counter (OTC) devices, making it possible for people to purchase hearing aids over the counter. These devices are suitable for people with mild to moderate hearing loss. For most users, there is simply no substitute for a professionally fitted hearing aid by a competent hearing professional.

Selecting a Hearing Aid Battery

Hearing aid batteries are available in both disposable and rechargeable forms. Most modern hearing aids use rechargeable batteries, which can be conveniently placed on a charger when not in use.

The Best Hearing Aid for Your Condition

There are numerous types of hearing aids available in the market, which can make the selection process seem overwhelming. However, a hearing professional can guide you in choosing a device based on your specific health condition and situation.

Insurance Coverage for Hearing Aids

Currently, Medicare does not cover hearing aids for adults, yet many insurance plans are beginning to cover hearing aids. It's always advisable to check your policy with your hearing professional.

When to Consult a Hearing Professional

If you're experiencing hearing loss that's interfering with your quality of life, it's time to schedule an appointment with a hearing professional. They can determine the extent of your hearing loss and whether hearing aids could help. If you already have hearing aids, it's recommended to get them checked by a hearing professional at least twice a year.

Additional Information on Hearing Aids

For more information about hearing aids, you can refer to the detailed information provided on manufacturers' websites. For those in Indiana, or looking for "hearing aids in Indiana", Key Hearing Aids professionals can help guide you in your hearing aids journey.

How to care for Hearing Aids

Hearing Aids are sophisticated devices that need regular care and maintenance to work effectively. We recommend that you schedule an appointment for your hearing aids to be cleaned and checked every three to six months.

When you remove your hearing aids, wipe them carefully with a dry, soft cloth or a specialized product such as Audio Wipes, which safely clean and disinfect the hearing aids and their earmolds. Inspect the portion of the hearing aids that fit down into the ear canal. Remove any visible earwax using the cleaning tool provided with your hearing aids--this is usually a brush or wire pick. Open the battery door and place your hearing aids in their case. Although your hearing aids may have an on/off switch, we still recommend opening the battery door to reduce the effects of moisture and to help prolong battery life.

There are also special sprays you can purchase that are designed specifically for the cleaning and disinfecting of hearing aids without causing damage to the hearing aid shell, earmold or circuitry.

Important "Do-Nots"

  1. Do not use solvents or alcohol on the hearing aids as there is a possibly that they can break down the hearing aid material or damage the circuitry.
  2. Do not place the hearing aids in direct heat; this includes leaving them in sun or in the car, placing them in a microwave or conventional oven, using a hair dryer on them.
  3. Do not allow your hearing aids to get wet. This includes showering or bathing, going to the swimming pool or sauna, and submerging your hearing aids in any kind of liquid for any reason.
  4. Do not drop your hearing aids. Your hearing aids may survive a fall on a carpet or other soft place, but hard surfaces can damage your hearing aids. As a precaution, we recommend placing a towel or other soft “landing spot” near the place where you are inserting or removing your hearing aids.
  5. Do not leave your hearing aids, hearing aid batteries or hearing aids care products within the reach of children or pets.

Remember, the world of hearing aids is vast and continually evolving. This guide aims to provide you with a solid foundation, but always consult with a hearing healthcare professional for personalized advice and recommendations.

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