Hearing loss has been a condition that has hounded humanity throughout the ages, whether it be due to injury, the consequences of illness, or even just the seemingly inevitable consequence of natural aging. But across multiple eras, mankind has been leveraging its ingenuity to tackle the issue in various ways, which has led to there being an interestingly rich history of hearing aids and associated precursor devices.
From the animal horn devices of the 13th-century and 18th-century ear trumpets, 19th-century carbon transmitters, early 20th-century vacuum tubes, mid-20th-century transistors, and the eventual transition from analog to digital, these devices have evolved in so many ways and will definitely continue to do so further. If anything, it seems like the rate of their development is accelerating.
So let’s take a look at their past and how they’ve changed to hopefully get a better glimpse of what their ongoing future might hold.
What is a Hearing Aid?
A modern hearing aid is a compact electronic device that’s worn in or behind one’s ear. Its purpose is to amplify sounds, thereby enabling individuals with hearing impairment to actively engage in daily activities, communicate effectively, and fully partake in various interactions. But even long before the advent of this modern technological format, humans have been experimenting with an evolving series of methods and devices for overcoming the challenge of impaired hearing. What we think of as a hearing aid today is quite different from the more primitive precursors that came before in the history of hearing aids. But ultimately, all of these devices share the same unifying intent: To channel, redirect, or amplify sound in a way that can compensate for an individual’s diminished hearing.
13th Century & Before
The earliest hearing aids were crafted using animal horns. Since as early as the 13th century, individuals with hearing loss utilized hollowed-out horns from cows and rams as rudimentary hearing devices. This historical pursuit to combat hearing loss can be traced back even further, with evidence found in ancient Egyptian manuscripts dating back to at least 1550 BC. Subsequently, both ancient Greeks and Romans proposed their own remedies for deafness, often involving medicinal concoctions and occasional objects inserted into the ear canal.
However, the effectiveness of these ancient treatments was questionable at best, potentially causing more harm than good, leading to their eventual abandonment. Although these early hearing aids made from animal horns lacked the ability to truly amplify sounds and thus offered limited efficacy, their utilization posed minimal risks, which perhaps contributed to their longevity as a treatment method that persisted for several centuries. The use of animal horns as hearing aids represents an interesting early chapter in the history of hearing loss management, highlighting the ingenuity and resourcefulness of early civilizations in addressing this prevalent issue.
The inception of the first man-made and officially recognized hearing aid took place in the 17th century, marking a significant milestone in the history of hearing aids. These pioneering devices, known as ear trumpets, were ingeniously designed to mimic the natural properties of animal horns.
By harnessing similar acoustic principles as the horns that preceded them, these early hearing aids channeled sound waves toward the ear. Their assortment featured diverse shapes, sizes, and materials. Jeanurechon, the renowned French priest and mathematician, is widely recognized as the pioneer who first mentioned the instrument in his esteemed work titled “Recreations mathématiques” in the year 1634.
18th & 19th Century:
Collapsible ear trumpets emerged in the 18th century, revolutionizing the portability of hearing aids. These devices were frequently tailored to individuals and were steadily gaining popularity. During the subsequent century, ear trumpets gained popularity and were commercially manufactured alongside other hearing devices, including hearing fans and speaking tubes. Ludwig van Beethoven, renowned for his extraordinary musical compositions, was not only an influential figure in the world of music but also a user of various bespoke ear trumpets. He relied on these specially crafted devices to enhance his auditory experience for an extensive period of time.
Today, these remarkable artifacts showcasing Beethoven’s connection to hearing technology are marvelously preserved and proudly exhibited at the Beethoven Museum in Bonn, Germany, offering a glimpse into the fascinating convergence of art and science in his life.
Late 19th & Turn of the 20th Century:
The development of the carbon microphone in 1878 paved the way for the development of various electric hearing aids in the early 20th century. These devices successfully amplified voices, allowing listeners to hear through handheld speakers. Although they were bulky and cumbersome, these devices marked the beginning of modern hearing technology and set the stage for rapid advancements in the history of hearing aids.
In 1898, Miller Rees Hutchinson introduced the Akouphone, the first portable hearing aid to utilize a carbon transmitter. This transmitter converted weak signals into stronger ones through the use of electric current. Despite its separate components, including a microphone, amplifier, headphones, and short-lived battery, the Akouphone was challenging to handle and had a high retail price, making it accessible to only a handful of people.
Although carbon hearing aids had limitations such as a limited frequency range and scratchy sound output, they remained in use from 1902 until the next subsequent breakthrough in technology: the vacuum tube.
Early 20th Century:
Starting from the 1920s, hearing aids utilizing vacuum tubes were capable of amplifying sound levels by up to 70 dB. This exceptional level of amplification was achieved due to the superior electric flow control of vacuum tubes compared to carbon. However, the primary setback was their size. Initially, these devices were large, resembling filing cabinets, and hence lacked portability.
By 1924, advancements in technology allowed for the reduction in the size of vacuum tube hearing aids, allowing all components to fit within a compact wooden box. These devices featured a receiver held up to the ear by the user. Despite the improvement, they remained bulky, heavy, conspicuous, and amplified all sounds indiscriminately. The journey of technological advancements continued, culminating in 1938 with the introduction of the first truly wearable hearing aid.
It comprised an earpiece, wire, and receiver for attachment to the user’s clothing. Regrettably, this model necessitated the use of a battery pack strapped to the user’s leg. Thanks to the technological advancements of World War II, the late 1940s witnessed the emergence of hearing aids featuring circuit boards and compact batteries, merging the batteries, amplifier, and microphone into a portable, pocket-sized unit. Despite its discreet marketing, these pocket units remained aesthetically unappealing due to the wires connecting them to individual earpieces.
Mid 20th Century:
Next in the history of hearing aids, the transition towards smaller and more discreet hearing aids commenced in 1948 with the invention of the transistor by Bell Telephone Laboratories. Transistors swiftly replaced vacuum tubes due to their evident superiority in various aspects. They facilitated the regulation of current flow, volume control, and the incorporation of multiple settings in one device. Moreover, transistors demanded less battery power, generated lower distortion and heat compared to vacuum tubes, and most notably, occupied a smaller physical space.
An engineer at Raytheon and the pioneer behind subminiature vacuum tube technology, Norman Krim, recognized the potential application of transistors in hearing aids. By 1952, Krim successfully developed junction transistors for hearing aid manufacturers. The advent of transistors not only facilitated the miniaturization of hearing aids but also enabled them to be discreetly worn either internally or behind the ear. Nonetheless, it appears that manufacturers were so enthused by the perceived advantages brought about by transistors that they may have overlooked conducting thorough tests on their transistor-based hearing aids.
They suffered the consequences of their impatience as devices appeared to malfunction shortly after customers purchased them, attributed to moisture that rendered the transistors inoperable. Hence, the manufacturers introduced a protective coating and the silicon transistor to address issues stemming from body heat, perspiration, and ambient humidity in general.
The newfound popularity and success of the latest hearing aids led to the sale of over 200,000 transistor models in 1953, surpassing the sales of vacuum tube counterparts. Seizing the opportunity presented by this emerging technology, Otarion Electronics pioneered one of the first nearly-invisible, in-the-ear hearing aids in the late 1950s.
Known as the Otarion Listener, this innovative device incorporated electronic components discreetly into the temple pieces of eyeglasses. The hearing glasses quickly gained traction, prompting the introduction of multiple variations by other industry players.
Late 20th Century:
Hearing aid technology, as we recognize it today, began to emerge in the 1960s. Early iterations consisted of a microphone positioned inside the ear, connected to an amplifier and battery unit through a small wire. These devices were conveniently clipped onto the ear. The 1970s saw the advent of high-speed digital-array processors that could be paired with minicomputers. However, it wasn’t until 1982 that an all-digital, real-time, array processing hearing aid was created at (CUNY) the City University of New York, as a research device for the study of digital signal processing.
Although it was a major step forward in the history of hearing aids, it was a rather unwieldy device. Inside, they had to cram in a minicomputer and a digital array processor, in addition to an FM transmitter and receiver. The 1980s saw the advent of digital chips for high-speed digital signal processing. These enabled fast processing but were too bulky and consumed too much power to be practical in wearable hearing aids.
At first, hybrid digital-analog models hit the market, but it was in 1996 that the first fully digital hearing aid model was unveiled, marking a significant milestone in the advancement of hearing aid technology. Over time, technology has reduced the drawbacks to practical levels for a digital hearing aid to finally become viable, most notably through the work of Engebretson, Morley, and Popelka at the Central Institute for the Deaf (CID).
By the year 2000, hearing aids had the capability to be programmed, allowing for user adaptation, flexibility, and precise calibration, and by 2005 digital hearing aids made up about 80% of the market for hearing devices. Digital technology is the same sort of circuitry that is used in modern cell phones and computers. Today’s hearing aids can be fine-tuned by an audiologist or other such hearing care professional and customized to an individual’s hearing needs. They can adapt to various listening environments and be networked to other high-tech devices such as computers, TVs, and phones. New features now allow compatibility with other electronic devices and greater accessibility in public spaces.
Currently available on the market are innovative hearing aids equipped with rechargeable batteries, eliminating the need for constant battery replacements. These intelligent devices are designed to adapt seamlessly to various listening situations, providing optimal sound quality without requiring any manual adjustments from the user. Furthermore, new strides in technology have led to the development of long-wearing hearing aids that can comfortably remain in the wearer’s ear canals for extended periods, up to several weeks at a time. This remarkable progress in hearing aid technology has greatly enhanced the convenience and effectiveness of hearing solutions for individuals with hearing impairments.
Speculations for the future:
Currently, hearing aids have made significant strides in adapting to modern technology. They can easily connect to iOS devices, allowing users to enjoy phone calls, music, and podcasts. In addition, ongoing developments are underway to enhance digital hearing aids by leveraging the audio processing capabilities of smartphones. This integration has transformed hearing aids into intelligent devices, with further advancements anticipated in the future.
Moreover, constant innovation continues to improve the overall design and functionality of hearing aids. Manufacturers are making strides in shrinking the size of hearing aids, ensuring they are more discreet and comfortable for users. The battery technology is also being enhanced, providing longer-lasting usability and reducing the need for frequent charging. As if that’s not enough, customization options for hearing aids are expanding to cater to individual preferences and specific requirements, ensuring they provide a truly personalized experience.
Additionally, beyond the aforementioned advancements, one of the most profound developments that could potentially emerge in the future of hearing aids is the integration of cutting-edge AI technology into these auditory aids. This integration has the potential to revolutionize the way hearing aids function and enhance the overall auditory experience for users. By leveraging new algorithms and machine learning capabilities, AI-powered hearing aids can intelligently adapt to various sound environments, dynamically suppress background noise, and personalize amplification settings based on individual preferences. This convergence of AI and auditory aids holds immense promise, as it opens up a whole new realm of possibilities for individuals with hearing impairments, empowering them to fully participate in the world of sound.
Rather than leaving the ever-more accessible process of customization and fine-tuning settings to a conscious effort on the part of the user. The AI-powered devices of the future might reflexively react and adjust to their user’s needs as casually as a seemingly seamless extension of the user’s own subconscious processing of the auditory input around them.
History of Hearing Aids Conclusion
Previously, in the history of hearing aids, new developments could take decades and previously even multiple centuries to see meaning fully changes and advancements in these auditory devices. But now, much like the rest of our world, these devices are changing at breakneck paces on an almost yearly basis at this point. The devices we know now have come an incredibly long way from the primitive roots of their past. And shockingly enough, it might not even be that much relatively further from now in a historical sense that they’ll develop into almost unrecognizably discreet devices that ever more seamlessly integrate with our bodies and our experiences of the modern world around us.
In addition to being the Founder and Editor-in Chief at HearingPeople.com, Luis Zuluaga is the founder and CEO of Florida Hearing Institute, an innovative hearing health enterprise in South Florida, focused on bringing high-tech hearing devices at affordable prices to people with hearing loss. Before his latest hearing healthcare endeavors, Luis served as President and Chief Operating Officer of Zounds Hearing Inc., a US-based hearing aid manufacturer that introduced many technical innovations to the hearing aid market.