Hearing Aid Basics

by Ashley Derrington, on February 13, 2019

What is a hearing aid?

A hearing aid is a small externally-worn device used to collect sounds with microphones and make those sounds louder through a small speaker in the ear canal. One way to think of it is that is like a tiny megaphone for your ear! Typically, they are best suited for people with mild, moderate or severe sensorineural hearing loss, but they are often used outside of those parameters. Some people do better with hearing aids than others.  

A hearing aid is generally worn in or behind the ear. A hearing aid is comprised of three basic parts: microphone(s), an amplifier, and speaker(s). The hearing aid receives sound through the microphone which is then converted to electrical signals and transmitted to the amplifier. The amplifier boosts the power of the signals, attempts to compensate for your hearing loss, and then transfers the signal to the ear through the speaker. Nothing is implanted, and everything is external. No part of the hearing aid integrates directly with or is connected to body.

There are many different types of hearing aids available on the market. Hearing aids vary widely by costs with some being available for a few hundred dollars while others are several thousand. The main differences between hearing aids are found in:

  • Design (e.g., size and color)
  • Technology (e.g., analog vs. digital)
  • Special features (e.g., wireless connectivity, activity sensors)

The selection of hearing aids is based on the type and severity of hearing loss, listening needs, lifestyle, and pocketbook. In many instances, the hearing aid selection at your local retail hearing shop is limited by the business relationship(s) your audiologist has with certain hearing aid manufacturers (do you research online first to understand what is really available).   

Hearing Aid Designs

Hearing aids vary in size and the way they're placed in your ear. For instance, some aids have earmolds or earpieces connected to the device to direct the flow of sound into the ear. Other devices are contained completely within the ear canal. Below is a list of some of the most common hearing aid styles, beginning with the smallest, least visible in the ear.

  • Completely in the canal (CIC) or mini CIC
    • Molded to fit inside the ear canal
    • Improves mild to moderate hearing loss in adults
  • In the canal (ITC)
    • Molded and fits partly in the ear canal
    • Improves mild to moderate hearing loss in adults
  • In the ear (ITE)
    • Made in two styles — one that fills most of the bowl-shaped area of the outer ear and one that fills only the lower part
    • Improves mild to severe hearing loss
  • Behind the ear (BTE)
    • Hooks over the top of the ear and rests behind the ear. A tube connects the hearing aid to a custom earmold that fits in the ear canal.
    • Appropriate for people of all ages with almost any type of hearing loss
  • Receiver in canal or receiver in the ear (RIC / RITE)
    • Similar to a BTE hearing aid with the speaker or receiver in the canal or in the ear. A tiny wire, rather than tubing, connects the pieces.
  • Open fit
    • Is a variation of the behind-the-ear hearing aid with a thinner tube
    • Keeps the ear canal open, allowing for low-frequency sounds to enter the ear naturally and for high-frequency sounds to be amplified through the aid
    • A good choice for people with mild to moderate hearing loss

Hearing Aid Processing Strategy

Hearing aids work differently depending on the technology used. There are many small differences, but a big difference is between analog and digital signal processing. Choice between the two is all about preference and type and level of hearing loss. Nearly all hearing aids nowadays are digital and analog hearing aids are few and far between. Nevertheless, it’s important to discuss the differences between the two.

Analog processing allows for more incoming sound information to be used (i.e., it is not broken up by digital processing), but less can be done to manipulate the signal. Essentially, analog devices amplify the entire input signal with some minor programming. Audiophiles and people who enjoy the entire range of sounds might prefer analog signals. People with a “flat” or easily programmed hearing loss are better suited for analog devices.

Digital processing allows for an audiologist to make more adjustments for hard to program hearing loss, and is better suited for people who don’t do well when all sounds are amplified. Digital processing “chops” or “cuts” the input into digital signals which can produce an exact duplication of sound but are not longer than the full sound input. In other words, digital aids can analyze speech and other environmental sounds which allows for more complex processing of sound in the amplification process. In this way, the aids are essentially improving their own performance in specific situations. They can be programmed to better fit the needs and patterns of a certain type of hearing loss.

Hearing Aid Special Features

Many hearing aids are equipped with additional special features that can assist in improving your ability to hear in certain situations. Some of these features are as follows:

  • Direct audio input
  • Directional microphones
  • Environmental noise control / noise reduction
  • Feedback suppression
  • Rechargeable batteries
  • Remote controls
  • Synchronization
  • Telecoils
  • Variable programming
  • Wireless connectivity

It’s important to note that hearing aids may not be the best solution to your hearing loss, so it’s advised to explore all options. As mentioned previously, do your research online as many retail hearing loss centers are closely tied to certain manufacturers. You may think they have all options, but there are strong incentives to sell more of one brand over another. Buyer beware!





Mayo Clinic

National Institute on Deafness and Other Communicative Disorders


Ashley is a 28-year-old from Atlanta, GA. She was born with bi-lateral, severe hearing loss, and wears a hearing aid in one ear and has an Esteem implant in the other. She plays soccer for the USA Women's National Deaf Team. 

Ashley worked in Los Angeles for a number of years in the entertainment industry. She now works remotely and is currently traveling the world in pursuit of adventure and perspective while also learning about the deaf and hard of hearing communities in various countries. Her travels can be followed on instagram @ashley5chanel or on her blog deaftattooedandemployed.com.


This is the experience of one patient. Individual results may vary. Esteem is a surgically implanted hearing device for a certain type and level of hearing loss. It can only be prescribed by a properly trained ear surgeon. Talk to your hearing healthcare professional for more information or contact Envoy Medical. 


Topics:hearing losshearing aidsAshley

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