How Do Hearing Aids Work? A Simple Overview
There are 28.8 million people in the United States alone who can benefit from using hearing aids, but only 16 percent of these individuals under the age of 70 have ever used one. Instead, many rely on other techniques or tools, including audio amplifiers and lip reading.
Hearing aids are amazing pieces of technology that can make a huge difference in the lives of people with hearing loss, yet despite this, not many people actually know how they work. Case in point: several members of my own family use hearing aids, but until recently I just wrote them off as “magic.”
But that description does hearing aids a disservice. The tech behind them is so interesting that they’re even better than magic! Keep reading to see what makes them so impressive.
Disclaimer: I want to acknowledge that Deaf culture has a complicated relationship with hearing aids that is outside the scope of this article. Because of this, one should not assume that everyone with hearing loss should use hearing aids. For some insight into this topic, please read Technological Tension in Deaf Culture or How Technology Could Threaten Deaf Identity.
When Are Hearing Aids Useful?
Many people with varying degrees of hearing loss use hearing aids. To understand how hearing aids work, first we must understand how hearing itself works. The video below is a great introduction to the science of hearing:
Audiologists use specific tests and measurements to adapt each hearing aid to an individual’s specific hearing needs. In general, hearing aids can help in several ways: amplify sounds, localize sounds, and isolate important sounds in noisy settings.
Professionals usually prescribe hearing aids to those who have damage to the inner ear or hearing nerves. Factors like disease, aging, exposure to loud noises, and medications are common root causes for this kind of hearing loss. On the other hand, conditions that affect physical ear structures are more likely to be corrected with surgery or medications.
Because hearing is so important for everyday interactions, the compensation offered by hearing aids can have an enormous influence on one’s quality of life. Some research even shows that individuals with hearing loss who receive hearing aids experience less frustration in their daily lives.
The Different Types of Hearing Aids
Of the many kinds of hearing aids out there, these are the most common models.
Analog and Digital Hearing Aids
These hearing aids are what most people think of when they picture a hearing aid. Analog hearing aids turn sound waves into electrical signals, which are then amplified to make the sounds louder. These hearing aids often have different settings that users can switch depending on their current situations.
Digital hearing aids use microchips to translate sound into digital information, then process that digital information into individualized sound outputs for the user. For example, the microchip may distinguish between human voices and background noise, then prioritize the voices over the background noise instead of amplifying all sounds equally.
All analog and digital hearing aids have three basic components:
- Microphone — Usually placed outside the ear or near the ear’s opening, the microphone picks up sound from the environment and translates it into an electrical signal.
- Processor/Amplifier — An amplifier modifies the electrical signal to make it louder. A processor translates the electrical signal to a digital signal and then analyzes this signal according to the audiologist’s specific programming.
- Speaker — Often placed inside the ear, this component converts electrical or digital signals back into modified sounds.
Hearing aids also have a combination of other components, such as batteries, wax guards, on/off switches, and positioning wires or molds.
Analog and digital hearing aids come in all shapes and sizes. The video below provides a quick overview of the many different styles of hearing aids available. If you’re in need of one, working with an audiologist is the best way to find a fit that’s perfect for you.
Bone-Anchored Hearing Aids
Many people with single-sided hearing loss, ear canal conditions, or conductive (middle ear) hearing loss choose bone-anchored hearing aids instead. These individuals have a functioning inner ear, but sound is not able to travel to the inner ear itself.
For this kind of hearing aid, a reversible surgery is performed to implant a receiver on the skull bone right behind the ear. The transmitter uses bone vibrations to send signals to the inner ear, allowing sound processing to occur.
Cochlear implants are recommended for specific types of severe hearing loss. An external device translates sound into digital information, which is then sent as electric signals through an internal implant directly to the auditory nerve. This approach bypasses existing hearing structures and allows the information to directly access the brain.
When you see videos online about people “hearing for the first time,” they are probably using a cochlear implant.
Using Hearing Aids With Technology
Recent developments in hearing aid technology provide users with a lot of options when it comes to using their hearing aids with other electronic equipment. For example, all iOS devices allow Bluetooth-enabled hearing aids to link directly to your iPhone or iPad.
Bluetooth-enabled hearing aids can also be used with a pocket-sized assistive device called a streamer. Streamers allow you to pair your hearing aids to most Bluetooth-capable devices so that you can easily listen to music, watch movies, or talk on the phone.
For non-Bluetooth hearing aids, professionals may recommend other assistive devices to help with daily activities like watching television or talking on the phone. There are also many apps available that promote learning sign language , and there are accessibility phone settings that can turn auditory alerts into visual or tactile alerts.
Some individuals may consider using a personal audio amplifier instead of a hearing aid. These amplifiers are worn in the ear and do nothing more than make sounds louder. In theory, they should mainly be used by people with normal hearing as a way to provide better-than-normal hearing in specific circumstances (e.g. listening to a low-volume TV at night).
However, it’s important to know that the FDA has not approved audio amplifiers for use by individuals with hearing loss. Even though hearing aids may be more expensive, they are the safest and most effective choice for hearing assistance.
Are You Considering Hearing Aids?
If you have noticed some symptoms of hearing loss and are interested in using a hearing aid, the best way forward is to talk to your physician or an audiologist. They will do tests to see whether a hearing aid is necessary or whether another strategy can fix your hearing loss.
If you are going to your first hearing aid appointment, this guide from betterhearing.org provides an amazing introduction into what you can expect.
This article is really just a basic introduction to the technology behind hearing aids. They are complex pieces of technology that improve every day. If you’re an iPhone or Mac user with a hearing impairment, look into real-time text calls .
Image Credit: Brian A Jackson via Shutterstock.com