Hearing aids are something that millions of people use each day. They come in a variety of shapes and sizes, and have become smaller and more versatile than ever before. With all of these interesting leaps in technology for hearing aids over the last two centuries, it is important to take a step back to see how far we have come. That is why we are going to take a look at the evolution of hearing aids throughout three distinct periods and levels of technology.
Early Hearing Aids
Before hearing aids were created for the widespread use of individuals who suffered from hearing loss, most people used something called an ear trumpet. Although it did not have a typical size, they were usually created in the shape of a horn that was designed to capture nearby sound. From there, the sounds would be funneled into the inner ear to give the person a better chance of hearing than they had before. It is important to note that these devices did little to amplify the sound and could only provide incremental acoustic improvement to those who needed hearing aids.
Carbon Hearing Aids
It was not until the late 19th century that the first true hearing aids were invented. Alexander Graham Bell’s telephone invention was the cornerstone of establishing the carbon hearing aid. These hearing aids would function by using a carbon microphone in conjunction with a magnetic receiver and battery. Sound would hit the outside of the microphone, which would then redirect the carbon pieces in the hearing aid, pressing against the diaphragm in accordance with how much sound was generated. The sound of these pieces moving through the diaphragm would act in the same way as sound waves, but came with many significant drawbacks.
For example, the sound of the carbon moving through the hearing aid would produce low quality sound, they could only pick up a few frequencies, and it could only help people with limited hearing loss.
Vacuum Tube Hearing Aids
Before the true electronic hearing aids, there were the vacuum tube hearing aids. They were first invented in the 1920s, and improved by Bell Labs with the invention of the first transistor for use in hearing aids. This functioned by using the transmitter from a telephone to change sounds gathered into electrical signals, which would then be turned into amplified sound as it moved through the receiver end. This magnificent development was one of the first truly portable hearing aids and was on the brink of the electronic hearing aid design. Though it was still seven pounds, it helped to convince investors and customers alike that new technology could be implemented for the sake of better hearing health.