Today’s Wonder of the Day was inspired by Anna. Anna Wonders, “how do hearing aids work” Thanks for WONDERing with us, Anna!

Listen

Do you like to spend time in nature in the early morning? As the Sun rises and spreads its light over the dewy grass, the quiet woods suddenly come to life. A chorus of sounds breaks forth as the crickets begin to chirp and the birds sing songs to greet the new day.

Most of us take these delightful sounds for granted. They simply fill in the background of our otherwise busy days. Some people, though, don't take these sounds for granted. For the millions of people who experience hearing loss, the sounds of nature fall on nearly-deaf ears.

Thanks to technology, however, more and more people who experience hearing loss can enjoy the sounds of nature, as well as the words of friends and loved ones. With a variety of devices, people with hearing loss can now hear things they never could before. What are we talking about? Hearing aids, of course!

When you speak to someone and they indicate that they didn't hear you, what is your usual response? Most people will repeat what they said in a louder voice. Increasing the amplitude of your voice increases its volume and will often allow people with hearing difficulties to hear what they could not at a lower volume.

Hearing aids work in much the same way, except they use technology to collect, amplify, and focus sounds so that hearing-impaired persons can hear the sounds around them. The very first hearing aids were large, mechanical devices that resembled large trumpets with long funnels. These awkward instruments collected sounds and funneled them into the ear.

Thanks to pioneering work by Alexander Graham Bell and Thomas Edison, manufacturers were eventually able to create hearing aids that could change sounds into electrical signals that could then be amplified and converted back into sounds that could be transmitted into the ear.

Hearing aids have four basic parts: a microphone, an amplifier, a speaker, and a battery. The microphone collects sounds from the environment and converts those sounds to electrical signals that are sent to the amplifier. The amplifier makes the signals more powerful and sends them to the speaker, where they're converted back to sound and broadcast into the ear. The battery, of course, powers all of these electronic components.

Many people suffer hearing loss as a result of aging, disease, or injury to the ear. Hearing aids help the working parts of the ear to function more easily by providing magnified sounds. Over time, manufacturers developed several different types of hearing aids.

Behind the Ear (BTE) models consist of a plastic case that fits behind the ear. A clear tube connects the case to a small piece of plastic, called the earmold, which sits inside the ear and transmits the sounds into the ear. In the Ear (ITE) models are larger and fit entirely in the bowl of the ear. ITE models are quite visible, but they accommodate batteries with longer life.

There are also two types of hearing aids that fit inside the ear canal. In the Canal (ITC) models are customized to fit the exact size and shape of a person's ear canal. They're small and inconspicuous, but they can also be difficult to adjust. Completely in the Canal (CIC) models are even smaller and fit entirely inside the ear canal, such that they're barely visible and a user must pull on a small wire to extract the device.

Early hearing aids featured analog technology, which means they merely amplified sounds. While this helped users to hear better, all sounds were amplified, including those that were unwanted. In the 1990s, digital hearing aids were developed. These modern devices, which account for nearly all hearing aids sold in the United States today, not only amplify sounds, but they can also digitally process incoming sounds to reduce feedback, eliminate background noise, and improve the overall clarity and quality of sounds for the user.

Wonder What's Next?

Join us in Wonderopolis tomorrow as we travel back in time to look at a military leader who stood tall on the world stage!