Hearing aid history

Edmond P. DeRousse May 13, 2019 at 6:19 pm

Hearing loss in humans has been around as long as there have been humans and it is attributed to many things. Its history includes brutal and violent stories dating back to the cradle of civilization. In that history are also stories of creative ways people have learned to communicate with each other.

 Archeologists have found skeletal human remains from 10,000 years ago in present day Iraq and Kurdistan with evidence of a condition called auditory exostoses. That is bony growths in the ear canal which can in severe cases cause hearing loss. In ancient Egyptian history there are references to a remedy for “ear that hears badly”. The remedy: injecting olive oil, ant eggs, goat urine, bat wings, red lead into the badly hearing ear.

Dating back to teachings of Greek philosophers such as Plato and Aristotle, unintelligent or simple minded were often used to describe people afflicted with deafness and the hard of hearing. They believed that the ability to reason and rationalize were only available to those who could speak.

Of course, these beliefs severely impacted the livelihoods of those who simply could not hear according to normal standards. Consequently, school children were segregated from the normal population and not provided the resources to help them learn on their own. The adults were unable to secure stable work.

Communicating with such a population, obviously, was a serious problem. To help with hearing loss, as early as the 13th century, those afflicted with hearing loss began using hollowed out animal horns as primitive hearing devices. In the 18th century a more modern ear trumpet was invented (such as the one pictured above). Instead of amplifying sound, it collected sound and funneled it through a narrow tube into the ear.

In the 19th century along came the practical application of electricity and the invention of the telephone. Because of the telephone people with hearing loss discovered they could hear conversation better with the telephone than they could in person.

In 1870 Thomas Edison, who himself experienced hearing loss, invented a carbon transmitter for the telephone. Because it amplified the electrical signal and increased the decibel level by nearly 15 decibels, the way was paved for carbon hearing aid technology. These aids had limited frequency range and a tendency to produce scratchy sound. In 1902 carbon technology gave way to the next wave: vacuum tube hearing aids.

Vacuum tube hearing increased sound level by as much as 70 decibels. But in the beginning, they were not very practical. The first ones were about the size of a filing cabinet. By 1924 all the components of the hearing aid were able to fit into a small wooden box with a receiver the user held up to the ear. A disadvantage was that it amplified all sound, not just the sound the user wanted to hear. The technology was a big improvement, but the aids were still heavy, bulky, and conspicuous.

In 1938, a wearable hearing aid was introduced. It consisted of an earpiece and wire and receiver which could be clipped to clothing. The aid needed a battery, though, which was strapped to the user’s leg.

Circuit boards and button sized batteries were developed during World War II. This technology allowed the battery, amplifier and microphone to become a portable, pocket-sized unit. The pocket unit was connected to the ear pieces with wires. Effective but still not the cosmetic appeal of today’s hearing aids.

In 1948 hearing aid technology changed again. Bell Telephone Laboratories invented the transistor. The flow of current and the volume of it can be started or stopped by a transistor. This makes it possible to have more than one setting on a device. In 1952 junction transistors allowed hearing aids to be made smaller. They could now be worn either inside or outside the ear. In 1953 over 200,000 hearing aids were sold.

Eventually, hearing aids were made out of silicon. This meant that they could be shrunk even further. In the 1960s Zenith Radio introduced a shrunken version where the microphone was placed in the ear and a wire connected it to an amplifier and battery that was clipped to the ear. That technology stayed virtually the same until the 1980s.

In the 1980s hearing aids went digital. A signal processing chip was introduced. Hearing aids were a hybrid digital and analog until 1996 when the first fully digital hearing aid was introduced.

By the year 2000 the digital technology in hearing aids had evolved to user customization. They now had the ability to be programmed, they were more flexible, and they could be fine-tuned. The technology used in todays’ hearing aids is the same used in cell phones and computers.

The hearing aids are fine-tuned by hearing care professionals and customized to an individuals’ needs and different listening environments. Other high-tech devices such as computers, televisions and telephones can also be connected to modern hearing aids. Some are even compatible with Bluetooth and have FM connectivity allowing connectivity with other electronic devices and accessibility in public places.

Hearing loss is the third most common health problem in the United States, the number one birth defect, and the number one reported work-related injury. According to People Hearing Better website there are many signs of hearing loss:

*The inability to hear female or child voices.

*The volume on the television is too low.

*The inability to hear high pitched sounds.

*Asking to have things repeated.

*Having a hard time understanding in large crowds.

*Depression: hearing loss not recognized can cause symptoms of depression.

*Avoidance of public places.

Hearing loss is not always easy to recognize. Obviously, one way to make sure your hearing is as it should be is to have regular checkups.

.    Hearing aid trivia

  1. The 1st mentioning of hearing was in a book published in 1588 by Giovanni Battista Porta. The book was “Natural Magick. It was about wooden hearing aids that were carved into the shapes of ears belonging to animals with superior hearing.
  2. Ludwig Van Beethoven suffered from hearing loss and was known to use a hearing trumpet.
  3. In the 1800s royalty had hearing aids built into their thrones. They were Special tubes incorporated into the arm rests. These tubes collected the voices coming from visitors kneeling before the throne. The voices were channeled into a special echo chamber and amplified. The sound would then emerge from openings near the monarch’s head. And supposedly no one knew.
  4. Ear tubes were introduced in the 1800s as well. One end of the tube was held to the speaker’s mouth while the other end was placed directly to the listener’s ear.




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