Hearing aids (and assistive hearing devices) have a surprisingly long and fascinating history. The ultra-sleek wireless devices that we enjoy today came about through centuries of experimentation and adaptation, and, although for some they still have in their minds the old-fashioned image of ungainly plastic blocks, the reality is that they’ve never been better, smaller and lighter. Let’s take a look at where they originated – you might be surprised to see how far things have come along!
The use of appendages to help with hearing goes back a long way. Hollowed-out animal horns are recorded to have been used as early as the 13th century, and Giovanni Battista Porta in his Magia Naturalis mentions wooden devices designed to mimic the ears of animals known for their acute hearing in 1588. It wasn’t until the 17th century that modernized ear trumpets really began to find their niche, though, with Sir Samuel Moreland inventing a large speaking trumpet made of glass. This first trumpet was quite unwieldy, measuring at some 2 feet 8 inches (81 centimetres).
Up until the late 18th century and the invention of collapsible ear trumpets, ear trumpets were made bespoke for particular clients. Notable examples include the Townsend Trumpet, made by the deaf teacher John Townshend, the Reynolds Trumpet built for painter Joshua Reynolds and the Daubeney Trumpet. In 1800, the first commercial collapsible ear trumpet was ear trumpets began production under the direction of London’s Frederick C. Rein.
Rein also sold hearing fans and speaking tubes, devices that helped amplify sounds while nonetheless remaining portable. These devices and the initial wave of ear trumpets were still considered overly bulky and ungainly, however, and so it wasn’t until the refinement of smaller, hand-held trumpets that they became far more popular.
F.C. Rein & Sons
Rein would go on to become something of a pioneer in the world of hearing devices and was even commissioned to create a specialized acoustic chair for the King of Portugal, João VI, in 1819. His marvellous device was a throne which boasted open mouths of lions on each arm which doubled as receivers for acoustics, which were then in turn circulated and amplified back through the internal apparatus, into the back of the throne and then transmitted through a speaking tube to the king’s ear.
Perhaps the closest non-electronic forerunner to modern hearing aid devices was Rein’s design known as the ‘acoustic headband’. These would feature a form of strap across the back of the headpiece designed to conceal the devices themselves. Rein had another headband type of hearing aid, too: the ‘Aurolese Phones’.
These were made in a variety of shapes, one particular type even incorporating a snail shell-like spiral design. At this time, assistive hearing devices were also hidden in furniture, clothing and accessories to be as discreet as possible and hide the fact that the individual in question had hearing difficulties. Rein’s devices became increasingly popular as a result and would remain so up until the advent of the telephone and microphone in the 1870s and 1880s.
Advances of the 19th century and the First Electronic Hearing Aids
Rein was by no means the only innovator of the Victorian period, however. The first curved behind-the-ear (BTE) hearing aid found success in 1836, and Jean Marie Gaspard Itard developed the first bone conduction device in 1812 following Jorrison’s accidental realization of the efficacy of the method in 1757. Patents for the first hearing aids followed in Britain (1836, Alphonsus William Webster) and the US (1855, Edward G. Hyde).
Dr Constantin Paul then developed the binaurical cornet in 1874, a type of binaural conversation tube with a headband to join the earpieces and a Y-shaped connection to connect the central tube to that of the ears.Towards the end of the century, breakthroughs gained pace rapidly, with Richard Rhodes inventing the Rhodes Audiophone in 1879, Enoch Henry Currier pioneering the Duplex Earpiece in 1885 followed by the first-ever electronic devices after the telephone and microphone rose to prominence. The efforts of Alexander Graham Bell, Charles Grafton Page, Innocenzo Manzetti, Antonio Meucci, Johann Phillip Reis, Cyrille Duquet and others were all key to the invention of this exciting new pair of gadgets.
Dr Constantin Paul then developed the binaurical cornet in 1874, a type of binaural conversation tube with a headband to join the earpieces and a Y-shaped connection to connect the central tube to that of the ears. Towards the end of the century, breakthroughs gained pace rapidly, with Richard Rhodes inventing the Rhodes Audiophone in 1879, Enoch Henry Currier pioneering the Duplex Earpiece in 1885 followed by the first-ever electronic devices after the telephone and microphone rose to prominence. The efforts of Alexander Graham Bell, Charles Grafton Page, Innocenzo Manzetti, Antonio Meucci, Johann Phillip Reis, Cyrille Duquet and others were all key to the invention of this exciting new pair of gadgets.
Since telephones could control the loudness, frequency and distortion of sounds, they would come to revolutionize how hearing aids were to be thought of from then on. Miller Reese Hutchison is credited with the first electric hearing aid – the Akouphone – in 1898. This progenitor of all modern hearing aids utilized a carbon transmitter so that the device could be portable. The transmitter used a weak signal and electric current to transform the said signal into a stronger version.
Early 20th Century Strides Forward
At the turn of the 1900s, Charles W. Harper began selling his version of the carbon-type hearing aid, known as the Oriphone. Soon after, Siemens followed suit and produced their first electronically amplified hearing aid in 1913 after joining the industry three years prior. These early models were somewhat cumbersome and difficult to carry around, yet they nonetheless helped steer the direction of hearing aids for the next decade.
Then, in 1912, the very first volume control for a hearing aid was introduced by the Globe Ear-Phone Company, before the hardships of the First World War took their toll and a period characterized by a lack of invention began. It took until two years after the Great War before the next milestone was achieved, and that came in the form of the first vacuum-tube hearing aid by Earl Hanson. Ironically enough, Hanson was himself a naval engineer. His device – the Vactuphone – used a telephone transmitter to transform speech into electrical signals, which would then be amplified when moved along the receiver. Hanson’s hearing aid would learn from Siemens’ early troubles and was light enough to carry around, weighing in at 7lbs or just over 3 kilograms.
The inter-war interregnum period would become particularly fruitful for hearing aid wearers. With the advent of vacuum technology, at last people who suffered from hearing loss would have something approximating a truly modern hearing aid. Custom earmolds then received their first US patent in 1926, paving the way for a system that has remained in place ever since. In 1932, the first wearable bone conduction hearing aid was introduced by Sonotone Corporation, followed by the first ‘Master Hearing Aid’ (MHA) – a device that would be used in the fitting of hearing aids – in 1936. The notion of miniaturization, of making things smaller and more compact, then began to make great strides forward. Vacuum tubes were successfully miniaturized, and a small wearable vacuum tube hearing aid was released by Telex in 1938.
The Aftermath of WWII
Upon the advent of the Second World War, hearing aid development took a backseat due to the scale of that conflict, however, the technological progress made by the various militaries that took part in that war was nonetheless an important factor in the continuing development of audio-assisting devices. One such example is the feature of automatic gain control, which received considerable bolstering alongside the advances in radar technology. Multitone of London would be the first to patent a hearing aid with the use of automatic gain control and introduced a wearable version in 1948.
Another key breakthrough was the balanced mercury cell from Samuel Ruben: this had many applications during the course of the war and was used in metal detectors, munitions and walkie-talkies, and so shortly after the battery system was adopted to hearing aids and other small electronic devices.
The Advent of the Transistor
The ongoing development of the transistor, which had first surfaced as a concept way back in 1907 but didn’t really come to the fore until the efforts of John Bardeen, Walter Brattain and William Shockley, would go on to dramatically change the way hearing aids operated.
Working at AT&T’s Bell Labs in Murray Hill, New Jersey, the three experimented with a variety of methods and came upon a way to produce a signal with greater output power than input via gold contacts and germanium crystals. They were awarded the Nobel Prize in Physics for their achievement in 1956, and considering the groundbreaking effect that the transistor has had on the modern world ever since it is one richly deserved. Indeed, transistors are today a key active component in practically all modern electronics, and they have been called one of the greatest inventions of the 20th century.
For hearing aids, transistors would now supersede vacuum tubes in every sense: they were smaller, required less battery power and produced far less distortion.
This would greatly assist the continuing process of miniaturization and would go on to mean that hearing aids were able to be worn almost entirely either within and behind the ear or on a pair of spectacles.
Over the course of the 1950s, several different versions were introduced and experimented with until the creation of the integrated by Jack Kilby in 1958, which marked the beginning of the transition from analogue to digital.
Digital Hearing Aids and the Latter 20th Century
The true beginning of the digital revolution started in the 1960s with Bell Telephone Laboratories’ first forays into digital processing for speech and audio signals. These early experiments were conducted on large, slow digital computers – far too bulky for a portable hearing aid – but they paved the way for how sound could be recorded and transmitted in future.
Later, in the 1970s, the first microprocessor came into being due to the efforts of Garett AiResearch, Texas Instruments and Intel. This opened the door to further miniaturization, as now it meant that the previously cumbersome computers of the sixties could be shrunk down to something far more manageable. Researcher Edgar Villchur was also key in this regard, as his analogue multi-channel amplitude compression device enabled audio signals to be split off into frequency bands. What this meant in real terms is that loud sounds could be amplified by a little, and quieter sounds by a lot; no longer would there be mere straight amplification of every sound.
The next step came through hybrid devices, those which used the analogue components (amplifiers, signal limiters and filters) in conjunction with a separate digital programmable part. These hybrids were particularly effective for the time due to their low power consumption and relatively small size. Etymotic Design, Mangold and Lane and Graupe & Co all managed to successfully produce and improve these early semi-digital models.
Then the 1980s saw further experimentation, culminating in the first fully digital hearing aid from the Nicolet Corporation in 1987. Unfortunately, this early edition proved unpopular, and Nicolet quickly folded; however, the race was now on between major manufacturers to create a more effective version. Bell Laboratories’ parent company AT&T ceased their activities in the hearing aid market at around this time and sold off their intellectual property to ReSound Corporation (now known as GN ReSound) in that same year. Their more advanced hybrid digital/analogue proved a huge success, and, spurred by this, other companies soon followed suit.
21st Century High-Tech
Since the turn of the millennium, digital hearing aids have become the norm (>95% as of 2005) and the amount of technology one can find in the now tiny devices is incredible. Nowadays, all hearing devices are fully programmable, and in 2004 Oticon introduced the first hearing aid to use a form of artificial intelligence for the processing of signals, the Synchro. This would go on to have a dramatic effect on how sound would be processed from then on, and lead to a slew of new inventions and innovations within the industry.
Among these, Starkey – who had previously found fame as President Ronald Reagan’s hearing aid manufacturer of choice in the 80s – pioneered the ELI in 2006, the first hearing aid to be Bluetooth-enabled. It was also the world’s smallest Bluetooth device and duly recognized for its ingenuity by Time Magazine as one of the best inventions of the year.
Shortly after came the Lyric (2008, now owned by Phonak), the first-ever fully in the ear hearing device which can be worn constantly for months at a time. WIDEX made the first hearing aid for babies in 2010. Then, in 2011, Siemens launched the Aquaris, the first waterproof hearing aid. Things were now gathering pace rapidly, and it wasn’t long until the first fully-streamable hearing aid (GN ReSound’s Linx, 2014) and internet-capable hearing aid (Oticon’s OPN) became available to buy.
Just a couple of years ago in 2019, Starkey launched their Livio AI range, a sophisticated AI-powered hearing aid that included health monitoring, mobile app functionality (which is now standard across all new hearing aid devices), and even fall detection – perfect for elderly wearers. Then in 2020, ReSound launched their ONE range, complete with their unique Microphone and Receiver In-Ear (M&RIE) technology to allow for a more natural sound.
Looking Beyond the Horizon
If we take a look in the aggregate at how hearing aids have developed over the centuries, it’s clear to see that explosive periods of progress are balanced by short interludes of stagnation. Given the sheer number of recent innovations, it might be safe to assume that we belong firmly in the former.
However, this might not necessarily be the case. Modern devices feature everything from wireless streaming, Bluetooth connectivity with other devices, on-the-go charging, assistive AI sound balancing, multi-directional microphones, health monitoring and even combined microphone and receiver in the ear tech. The technology now is so finely-tuned and so much functionality is packed into each device that it could mean that we’re heading towards a period of relative stagnation as new ideas become fewer and fewer.
Then again, with advances in artificial intelligence coming in at an alarming rate, it could also be that we’re set for yet another set of revolutions. If recent trends are anything to go by, then perhaps this is the likelier answer.
Either way, for hearing aid wearers and professionals alike, it looks like we’re in the most exciting period of all. Long may it continue!