History of Hearing Aids

by Rachel Anderson

Happy Disability History Week! To celebrate this week, we will be highlighting the history of a few different AT devices. 

Did you know hearing aids have been around for centuries?

Hearing Aid "Trumpet"

The earliest known hearing devices date back to the 17th and 18th centuries. They were horn-shaped and made from shells, glass or wood.  These hearing "trumpets" were used by people that were hard of hearing by holding them up to their ear to amplify sounds. In the 1800s, it became more common for for these trumpets to made from metals like copper and brass.  Also during this century, efforts to conceal these hearing aids began by incorporating them into hats, collars, bouffant hairstyles, beards, or even clothing. Another invention from the 1800s that was not as common as the trumpet was an ear tube. Ear tubes consisted of a tube being held up to a speaker’s mouth and then the other end was placed directly in the person’s ear, thus eliminating the environmental noise.

Early 20th century hearing aids

Until the late 19th century, hearing aids only offered a small amount of sound amplification. It wasn't until the discovery of electricity and the telephone that rapid advancements in this technology were made.  When the telephone was invented, Thomas Edison, who was hard of hearing, wanted to improve the sounds delivered by this machine and invented the carbon transmitter which amplified the electrical signal. His work, along with many others in subsequent years, led to the creation of the three-element vacuum tube hearing aid in 1907. At first this device was too large to be portable, but by 1924 Western Electric created these same components and made them small enough to fit into a box that weighed only four kilograms. The box was connected to a receiver that users had to hold up to their ears. These devices were usually worn around the neck, and they still had a relatively heavy battery that only lasted a few hours. 

In 1938, electronic manufacturers in Chicago developed the first wearable hearing aid that consisted of a wire connecting a small earpiece to an amplifier-receiver that could be clipped onto the the wearer's clothes. Even further developments with this technology occurred in the 1950s when the transistor was invented. The invention of the transistor changed hearing aids completely. In fact, two years before transistor radios were popular, people were already using them in hearing aids. In 1953, more than 200,00 transistorized hearing aids were sold. In 1957, companies  made the hearing aid even smaller and more concealable by putting all of the electronics entirely into a pair of eyeglasses! Finally, in the 1960s, Zenith Radio advertised the first completely behind the ear model of a hearing aid. It weighed just 7 grams was 500 times more reliable than the hearing aids built with transistors.
  
Over the years, hearing aids have shrunk drastically in size and have increased in their abilities to function for individuals. Many hearing aids now are virtually invisible and these important devices have helped people that are hard of hearing maintain their independence. Do you use a hearing aid?  Tell us below in the comment box about what style works best for you. 

http://www.emoryhealthcare.org/ear-nose-throat/audiology/hearing-aids.html