The Evolution of Hearing Aids: From Ear Trumpets to Digital Devices

Our understanding of hearing loss and its treatment with hearing aids has evolved dramatically since the first historical recording of hearing challenges. The history of hearing loss spans centuries, and there have been multiple attempts to alleviate and correct it. Hearing aids and assistive listening devices are far from being a novelty, and history counts numerous primitive devices and solutions. Although perfection remains an elusive goal, the journey of hearing aid technology and the role of the audiologist have been one of continuous improvements.

Animal Horns and Ear Trumpets

Hearing loss has always been a part of human history. The earlier recordings of hearing aids appeared in the 13th century where individuals with hearing loss used the hollowed-out horns of animals as hearing devices. This rudimentary solution was designed to collect and direct the sound through a narrow tube into the ear. There was no sound amplification available.

Throughout the 17th and 18th centuries, the concept of ear trumpets, built on the same principle as animal horns, developed with figures such as Jean Leurechon, Athanasius Kircher, and John Townsend, who even designed a collapsible conical ear trumpet. In 1800, London began to produce ear trumpets commercially, yet those hearing aids remained bulky.

Yet, the 19th century was marked by a technological transformation that helped improve hearing aids. In 1816, the invention of the stethoscope did not just support medical examination but also contributed to improving hearing for individuals with hearing loss. In 1819, an acoustic chair designed for the king of Portugal showcased advanced sound receiving technology. This contributed to the development of many hearing device innovations throughout the 19th century:

• An acoustic horn was developed, comprising a tube with two ends and a sound-capturing cone. It could fit in the ear.
• A pioneer of hearing aids, F.C. Rein took inspiration from the acoustic chair and developed hearing aids concealed within headgear, such as acoustic headbands. For the first time, hearing aids sought not only hearing comfort but also invisibility.

First Electronic Hearing Aids

The transformative 19th century brought not only the ideal of concealed hearing aids, but also the first telephone, a device that enabled long-distance conversation with the application of electricity. People with hearing loss noticed they could hear better through the telephone than IRL.

Thomas Edison recognized the potential of the invention and developed an amplification transmitter for telephones in 1870, which could amplify sounds by 15dBs. This paved the way for carbon hearing aids in 1902.

Vacuum Tube Hearing Aids

In the 1920s, hearing aids began incorporating vacuum tubes for amplification by as much as 70dBs. However, the first vacuum tube instruments were large and non-portable. By 1924, all components could fit into a small box with an external receiver. Amplifying hearing aids remained bulky until 1938 where the first wearing hearing aids equipped with an earpiece, wire and receiver appeared. Technological advancements during WWII contributed to further developing portable hearing aids with circuit boards and button-sized batteries, yet the connection remained visible through a wire.

Transistor Hearing Aids

In 1948, the introduction of the transistor helped innovate hearing aid technology. Engineer Norman Krim recognized the potential and created transistors for hearing aid companies in 1952. This marked the shift towards smaller, less visible hearing aids that allowed individuals some level of control over the settings. In the late 1950s, Otarion Electronics capitalized on the new technology by launching the first hearing aids that could be worn almost in its entirety in the ear, using hearing glasses to contain the electronics.

The transistor technology continued to evolve and shrink through silicon use. By the 1960s, the microphone could be placed inside the ear and wired to the amplifier and battery unit attached to the ear. This remained unchanged until the 1980s with the digital signal processing chips.

Analog to Digital Hearing Aids

The first hybrid hearing aids appeared in 1996. By 2000, hearing aids could be equipped with programmable features for advanced customizations and fine tuning. By 2005, digital hearing aids made up 80% of the hearing aid market. Equipped with technology similar to cell phones and computers, they can be fine-tuned by an expert audiologist to adapt to different needs and listening environments.

Digital hearing aids are also compatible with other electronic devices, allowing for more customization and comfort. Today’s hearing aid technology continues to grow and advance, presenting more convenience and sustainability through rechargeable batteries, enhanced comfort and smart usability.

Nowadays, hearing aids continue to strive for convenience, comfort, and enhanced quality of life with technologies that make them more accessible and adaptable to the wearer. If you find yourself wondering whether you need hearing aids, we encourage you to reach out to an in-house audiologist at Advanced Hearing of Brighton at 810-355-2245 for guidance about hearing health.