One of the most important inventions of the last century has been the digital hearing aid. These devices have revolutionized the world for people who suffer from hearing loss. That is why it is crucial that we continue along the endeavor towards making more functional and technologically driven devices in the future. Before we look to the horizon, though, it may be a good idea to take a step back and see where we have come from in terms of hearing aids.
The Ear Trumpet
The earliest for of hearing aids were called ear trumpets. They came in a variety of forms, but they all had a very basic concept. The individual would put the small, hollow end of a horn or metal trumpet device into their inner and then direct the flared end towards the sound that is being made. This helps the sound travel through the trumpet and to be heard by the user. While it was a valuable concept and was the source of many novel creations, it was still horribly limited by the fact that it was not mobile and could not truly amplify sound.
Carbon Form Hearing Aids
One of the developments that were made in hearing aids came about in the late 19th and early 20th century. This was called the Carbon Hearing Aid, and used a magnetic receiver, carbon microphone, and a battery in order to bolster hearing in individuals across the nation. To understand this concept simply, the user would place their ear against the diaphragm. As sound hit the carbon microphone, it would send pieces of carbon across the diaphragm, simulating that noise but also amplifying it through the microphone. The result was that louder sounds were made and the person was better able to hear them.
Of course, this early design came with plenty of flaws such as only providing low quality sound and a grainy sound at that due to the carbon movement. Also, since the battery needed was so heavy and the person had to be on a level ground to use it, this hearing aid was not mobile.
Vacuum Tube Hearing Aids
The last stop before we get to the electrical and digital ages of hearing aids comes with the vacuum tube hearing aid. This tool was used during the 1920’s and integrated many parts of the telephone at that time to become a very successful hearing aid. The device weighed seven pounds, but it was also able to amplify sound. The vacuum tube was used with a transistor to turn sound into electrical impulses, and then back into amplified sound. This allowed people to hear sounds at a much higher volume than before, and they could take it just about anywhere. The major drawback was that the batteries never lasted long enough for the device to be used all the time.