4.14 — Hearing Aids: Rediscovering Sound

Host Walter Isaacson and guests trace the evolution of devices used to help us hear better, looking to the past for information about the earliest hearing aids all the way through the advanced versions available now.
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Hearing aids have come a long way from the days of holding seashells up to the ear.

In this episode, we follow the ever-improving quality of the latest in hearing aid technology and look at some of the ways that this humble device might continue to evolve.

What you’ll hear in this episode:

● A device fit for a queen (0:00)
● A problem as old as humankind (2:43)
● Can you hear me now? (5:05)
● Hearing aid prototypes (6:48)
● Going mini (8:56)
● Computers come to the rescue (11:34)
● Going to the source: the auditory nerve (16:38)
● Putting the AI in hearing (22:17)
● A solar solution (26:30)

“Hearing aids were the first personal portable communications devices.”

— Mara Mills, associate professor of media, culture and communications, New York University

Guest List

  • Dr. Jaipreet Virdi is a historian at the University of Delaware whose research focuses on the ways medicine and technology impact the lived experiences of disabled people and the author of Hearing Happiness: Deafness Cures in History.
  • Dr. Mara Mills is a professor of media, communication and culture at New York University and the author of the book “On the Phone: Hearing Loss and Communication Engineering.”
  • Dr. Harry Levitt is the Chief Scientist with the company Advanced Hearing Concepts Inc. was a researcher at Bell Laboratories in the 1960’s, and former head to the Digital Sensory Aids Laboratory at the City University of New York.
  • Dr. Michael Merzenich is a professor emeritus at the University of California, San Francisco, one of the scientists who helped create the cochlear implant and author of “Soft-Wired: How the New Science of Brain Plasticity Can Change Your Life.”
  • Brandon Sawalich is the president of Starkey. Starkey’s Livio AI is the world’s first hearing aid to feature integrated sensors and artificial intelligence.
  • Tendekayi Katsiga is the co-founder and operations manager of Deaftronics. Deaftronic assembles and provides solar rechargeable hearing aids and accessories for the hearing impared in rural Africa.

Walter Isaacson: It’s August 9th, 1902 and Edward VII is about to be crowned the new King of England. It’s a grand affair. A procession of 30,000 military personnel escort Edward and Alexandra of Denmark, his wife and soon to be queen, down the street in their royal carriage. Flags and banners flap in the wind as they make their way to Westminster Abbey. The streets are lined with their loyal subjects, and spectators are waving from apartment windows overlooking the procession. 8,000 people have gathered to watch Edward’s coronation, including luminaries and royalty from around the world. Among these glittering nobles is a guest of a notably humbler sort, a 26 year old American inventor named Miller Reese Hutchison. He’s there on a personal invitation from none other than Alexandra of Denmark.

Walter Isaacson: Alexandra is one of Hutchison’s clients and the avid user of one of his peculiar electrical contraptions. In fact, today she’s planning on openly using one of his inventions as she watches her husband’s coronation, but it’s not something to help her see the coronation. Instead, it’s something to help her hear it. The invention she’s using is called the Akouphone. This bulky device amplifies audio signals, allowing the partially deaf Alexandra to follow the details of the ceremony. Today, we’d call it one of the first electrical hearing aids. For the new queen, who always felt isolated by her hearing difficulties, it was a revelation. But even so, on that cloudy day in London, neither she nor its inventor could imagine how a hearing aid technology would go on to drive technological innovation over the next century.

Walter Isaacson: I’m Walter Isaacson and you’re listening to Trailblazers, an original podcast from Dell Technologies.

Speaker 2: As we mature, the hearing starts to deteriorate.

Speaker 3: The smallest end would be placed in the ear, with the horn facing outwards.

Speaker 4: The modern hearing aid completely transformed society.

Speaker 5: Can you hear me clearly?

Speaker 6: Oh man, this sounds much better.

Walter Isaacson: More than 460 million people across the world suffer from some sort of disabling hearing loss. Whether it’s due to illness, injury, or genetics, it’s a problem that’s been around as long as we have.

Mara Mills: Improvised hearing aids are as old as humankind.

Walter Isaacson: Mara Mills is an Associate Professor of Media Culture and Communication at New York University.

Mara Mills: Hearing aids start with the gesture of a cupped hand behind the ear. Natural objects like shells and horns have also been repurposed as hearing aids around the world since ancient times. But in Europe, in the early modern period, we start to see itinerant tin dealers selling things like ear trumpets, so-called tin ears, along with cups and other household objects.

Walter Isaacson: Ear trumpets were the most prominent hearing device of the 19th century. It was a horn shaped device that funneled and amplified sound into the ear. And there was a sizeable demand for this new technology.

Mara Mills: I would also say that hearing aids were the very first personal portable communications devices. They created a market for these devices before electronics, and long before the present. So hearing aid firms and hearing aid inventors had to come up with ways to make hearing aids wearable, and sometimes ways to make them fashionable.

Walter Isaacson: In the late 1790’s, a London businessman by the name of Frederick C. Rein set up shops selling ear trumpets and other assistive devices. They were often disguised in everyday objects like headbands, fans, and false beards to hide the user’s conditions.

Walter Isaacson: Jaipreet Virdi is the author of the book Hearing Happiness: Deafness Cures in History.

Jaipreet Virdi: Rein was a prestigious company with many of their expensive products often used by members of the British royal family. To own a Rein trumpet was to be part of a privileged and elite social status which, of course, not everyone could be included in. At the same time, ear trumpets were portrayed as objects of ridicule.

Walter Isaacson: But no device would have as much impact on the hearing aid as the greatest auditory innovation of the 19th century, Alexander Graham Bell’s telephone. The word telephone was actually coined decades before Bell’s invention. It was even used to describe ear trumpets. Bell himself had deep ties to the deaf community. In fact, his invention owed more than a little to hearing aid technology.

Mara Mills: Because Alexander Graham Bell famously worked as a deaf oral teacher, the myth often circulates that his telephone was designed as a hearing aid. Now it turns out that that’s not true. What is true is that he was inspired to design a telephone, made of various materials that undulated an electrical current, based on a teaching tool that he used with deaf students. The tool that he used to inscribe or write down sound waves for deaf students to then read. Now, his telephone was inspired by deaf education, but it was not itself meant to be a hearing aid. However, it was almost instantly repurposed into the very first electrical hearing aids.

Walter Isaacson: In an early example of hardware hacking, some hearing impaired users jerry rigged the telephone and used its powers of amplification to turn them into improvised hearing aids. But the sound wasn’t loud or clear enough for everyone. The technology needed its next leap forward. Miller Reece Hutchison was an Alabama born inventor with an interest in hearing. Long before he attended Edward VII’s coronation, he was inspired by a friend who lost his hearing after a childhood bout of scarlet fever. Hutchison noticed that his friend couldn’t even hear the extremely loud whistles of the steamboats they traveled on. So he used his training as an electrical engineer to design a series of ingenious devices that took advantage of a new and revolutionary piece of technology, the carbon transmitter. The carbon transmitter converts sound into an electrical audio signal, and it was an important component of early electric hearing aids. Most famous of Hutchison’s devices was Queen Alexandra’s cherished Akouphone. It was a large and heavy device that can only be used if it lay flat on a table. And while it caught the attention of royalty, it wasn’t universally loved.

Jaipreet Virdi: Even though the Akouphone was a novelty and a testament to the power of electricity to deliver sounds to deaf ears, the bulky and awkward features of the machine made it unpopular. Some deaf people testified that they’d been fooled by the illusion of hearing sound, when in fact they were only feeling vibration. It had other problems, too. The electric components [inaudible 00:08:27] when the battery got too hot, and it was heavy to carry around. So two years later, in 1902, Hutchison and his business partner unveiled the Acousticon, a body worn carbon hearing aid with a single microphone, and powered by batteries lasting from a few hours to a week. Even though the Acousticon was more practical and resilient, it did not provide sufficient acoustic gain for users with more than moderate hearing loss.

Walter Isaacson: It took one of the most important innovations of the early 20th century to transform hearing aids into being truly portable devices, the vacuum tube. The vacuum tube was invented in the 19th century, but perfected in the 1920’s by the telecom giant AT&T at their Bell Labs Research Facility. Vacuum tubes were essentially fragile glass tubes, but they had the ability that amplify electrical signals and sound with minimum power. They revolutionized communications technology in many ways, enabling the spread of radio and long distance telephone calling. And they were perfect for hearing aids.

Jaipreet Virdi: Vacuum tubes enabled hearing aids to shift from being portable devices to being wearable devices. So the person could wear the hearing aid on their clothes, or in body harnesses, or keep them in pockets rather than carrying them in accessory cases.

Walter Isaacson: Vacuum powered hearing aids came of age in the 1930’s as tubes became smaller and easier to manufacture. But they weren’t perfect. They still required harnesses, and straps, and awkward battery packs. But they were more accessible than older hearing aid technology, and this helped open up an entirely new market. It turned out that this market would go on to push the electronics industry further into the age of miniaturization. It pushed towards the tiny computer you could carry around in your pocket every day.

Mara Mills: And hearing aid users in particular were consumers of miniaturized electronics. They were manufacturers of them, sometimes even inventors. And this is true from the vacuum tube era through integrated circuits in the ’70’s. Why? Well, again, due to the stigmatization of hearing loss, users generally demanded small or even invisible devices. And by that point, they were well known as a large consumer market and the group who were willing to pay an initial high price for small innovations for these so-called luxury items that were hearing aids. Hearing aid users became the first consumer market for printed circuits, transistors, and integrated circuits. Although those components were invented for other purposes, they were marketed first with hearing aid users.

Walter Isaacson: Nowhere was this more evident and when it came to what is arguably the most significant invention to come out of Bell Labs, and quite possibly the most significant invention to come out of the 20th century, the transistor. Invented in 1947, the transistor is a miraculously small device that can amplify or switch electrical signals. It paved the way for the computerization of the next 70 years. Somewhat amazingly, AT&T let companies working on hearing aids use transistor technology royalty free. Those companies and their customers would go on to push the technology even further down the road. The hearing aid market was so important for the further development of the transistor, that in 1953 the New York Times even called hearing aid users the guinea pigs of transistorization. And while hearing aids had reached an acme of evolution as analog electrical devices, there was still more that the new computer technology could bring to the table.

Walter Isaacson: Computer processors could do much more than just amplify sound. They could reshape, smooth, and change its properties to better adapt to the hearing aid users, users who each have their own unique auditory challenges. The only problem was that computers in the 1970’s were very large, and by today’s standards, very slow.

Harry Levitt: My view, in the very beginning, was let’s simulate the most fancy hearing aid that you could possibly think of digitally.

Walter Isaacson: This is Harry Levitt. He’s a former member of the Digital Sensory Aids Laboratory at the CUNY Graduate School. He was also a researcher at Bell Labs. His goal was to help create a digital hearing aid.

Harry Levitt: The dynamic range of human hearing changes as a function of frequency, and it is very different for a person with a hearing loss. You have to know what the person with hearing loss has a limited dynamic range of sound. That’s all very difficult to deal with with a traditional analog signal.

Walter Isaacson: Levitt arrived at Bell Labs in the early 1960’s, when it was at the peak of its powers. Its campuses were bustling complexes full of scientists in white lab coats and oversized computing devices with blinking lights, big plastic dials, and cables running in every direction. The age of the microprocessor and the compact personal computer was in its infancy. But the hearing aid would be one of the first to benefit from this new technology. In the 1970’s, Levitt and his team pushed the very limits of computer technology. They were committed to improving the audio processing capabilities of the era’s hearing aids.

Harry Levitt: We were using a mainframe computer, very large IBM, that had developed a special device known as an analog to digital converter. And you had to play your tape recorder, play what you wanted to be digitized. A few hours later, the computer department would call and say, “Okay, your stuff has been digitized in the computer.” And then I’d arrange for it to go from a digital to analog converter, then they’d send me the actual tape. So this was like a 24 hour turnaround for any attempt at doing any digital work.

Walter Isaacson: An analog electrical signal, digitized by a computer, and then printed onto a tape so that the digital signal could be read by an analog hearing aid. That’s quite the process, and not a very efficient one. So the solution ended up being a semi digital, semi analog hearing aid. It wasn’t until 1984 that the first fully digital hearing aid would arrive on the market.

Harry Levitt: I did work as a consultant to the company that produced the first commercial digital hearing aid. It was called the Phoenix. It was body-worn. It was inconvenient to use, had a wire between the body-worn unit and the thing you want your ear. It was very visible, and people who could have benefited from it didn’t want it because it was inconvenient and told everybody in the world that they had a big hearing aid. So it died. But it was the world’s first commercial digital hearing aid.

Walter Isaacson: Once again, the conspicuousness of the hearing aid worked against it, and there were no false beards or decorative headbands to hide it. But a new hearing technology was in the works that would utilize a hardware that was far more internal in more ways than one. While researchers like Harry Levitt worked on methods of amplifying and enhancing audio signals, another approach began to take shape in the early 1970’s. Instead of clarifying the signal that reached the damaged part of the ear, this new method involved routing around the damage completely. It sent an audio signal directly to the auditory nerve that bridges the ear and the brain.

Michael Merzenich: The auditory nerve is usually significantly intact in deafness, even though the ear is substantially or completely dysfunctional.

Walter Isaacson: Michael Merzenich is a professor emeritus at the University of California, San Francisco, and one of the scientists who helped create the cochlear implant.

Michael Merzenich: And that’s because the most sensitive structures in the ear, to damage or to loss, are actually the cells that transduce the acoustic information, the sound information, the sound energy. So they die first, they’re most sensitive to damage and loss. But almost always, even after they die, the nerve is still significantly intact. And it’s sitting there inactive because there’s no way that it can be excited by sound now that the translational machinery is damaged or destroyed.

Walter Isaacson: Merzenich and his team had a big challenge. They had to figure out how to send audio information that was detailed enough so that the brain could interpret it as a human language. By using an implanted device to shock the auditory nerve, they hoped to create patterns the brain could recognize as speech. But their first attempts were, to put it lightly, crude.

Michael Merzenich: I liken it to playing Chopin with your fist or maybe your forearms. When you’re shocking the nerve, it’s very difficult to control the patterns of input by shocking it with any sort of sophistication. The inner ear very elegantly represents the details of sound. I mean, think of the beauty of listening to a complex piece of symphonic music and you understand what an incredible job it’s doing. So, not surprisingly, when we turned the devices on, people didn’t particularly like what they heard. They were excited they heard something, but they weren’t particularly excited about what they heard. Because they said it sounded like a robot speaking, or it sounded like maybe an alien voice that they’d maybe probably never understand.

Walter Isaacson: But in trying to increase the fidelity of their implant, Merzenich, and his team stumbled into a massive insight. An insight that had profound implications for how we understand the inner workings of the brain.

Michael Merzenich: We came in to the laboratory one day and the person told us that they had begun to hear everything. And they claimed that it sounded like it sounded before they lost their hearing. We realized, quite quickly, that this was not a miracle of our engineering. We were trying very, very hard to improve the sophistication of that coding and that engineering, but the brain did it. The brain was making the correction. Basically we began to realize that the brain had a capacity to make a marvelous, in a sense, self-correction with even this very limited information it was receiving, and interpret what it heard in a meaningful way. And interpret, in terms of within the framework, of its long ago learned native language.

Walter Isaacson: In other words, it wasn’t the technology that was improving, it was a test subject’s brain. The longer they used a cochlear implant, the more their brains changed and adapted. They were now able to understand the signals they were being fed. Merzenich calls this brain plasticity, and it’s been the focus of his career since the 1970’s. His work since has looked at the various ways that the brain can rewire itself in response to different stimuli. And it’s helped us better understand how we learn. The cochlear implant has been an incredibly successful technology. Since its invention, over 600,000 patients are estimated to have undergone implant surgery. But, ultimately, it’s the human mind that does most of the heavy lifting.

Michael Merzenich: This was a product of an incredible capacity of the brain to modify itself, to make sense out of information that it received. Even when that information was in very different or substantially different forms, the brain made sense of it. This is a testimony to the power of plasticity that’s with us. With every one of us.

Walter Isaacson: The hearing aid continued to evolve through the 1970’s and ’80’s, but one of the most significant events in the history of the hearing technology didn’t take place in a laboratory or research institute, it happened at the White House. On September 7th, 1983, Ronald Reagan’s press secretary announced to the world that the president had been fitted for a Starkey brand hearing aid. Reagan needed the device because of all the loud gunshots he was exposed to on the sets of the western films he starred in. This remarkable admission was a godsend for the industry. It saw a significant and immediate jump in sales. But more importantly, it helped change the public perception and stigma around hearing aid technology.

Brandon Sawalich: When he came out, it was sociably okay for people to go seek hearing help. And it almost puts Starkey out of business because it couldn’t keep up with demand.

Walter Isaacson: Brandon Sawalich is the president of Starkey.

Brandon Sawalich: The stigma has been there. And it’s my goal, and everybody’s goal here, is really educating, but also wanting to overcome that stigma.

Walter Isaacson: By the late 1980’s, the goal of a fully digital hearing aid had finally been achieved. And while the quality increased steadily over the next 20 years, it took the smartphone revolution to completely change the hearing aid. Starkey’s newest product is called Livio AI. It’s a hearing aid that takes full advantage of advances in portable computing and machine learning technology, and it’s doing a lot more than simply improving the hearing capabilities of its users.

Brandon Sawalich: When we launched Livio AI in August of 2018, it was the first step really of our path of, as we say, hearing health and wellness. One of the most common things with hearing loss is social isolation. You start drawing inward, you don’t engage. And so then we have what we call our brain and body score. The hearing aid is embedded with sensors where it’s measuring somebody’s steps, along with the brain score, where they’re monitoring their social engagement.

Brandon Sawalich: It also translates up to 27 different languages. Livio AI is the first and only to do these features.

Walter Isaacson: Paired with a smart phone app, it’s even able to adjust the sound it amplifies to better suit the environment of the user. Livio AI has proven so popular that some people who do not suffer from a hearing loss are starting to use it, including Brandon’s son.

Brandon Sawalich: He wore them to school proudly. And then his friends started seeing them, and then their moms started asking my wife how do they get a pair. Because he was streaming music, showing them the translation, and all the other different features outside of it being a hearing aid.

Walter Isaacson: But as with every advance in hearing aid technology, digital hearing aids haven’t been universally embraced. Some users are reluctant to change a device so intimately connected with the way they communicate with the world.

Walter Isaacson: Jaipreet Virdi.

Jaipreet Virdi: So I’m deaf and I’ve been deaf since age four, when I lost my hearing to meningitis. And for most of my life, I wore analog hearing aids, behind the ear models. And when digital hearing aids entered, I initially resisted them because I dreaded the exercise of readjusting to my surroundings with the instrument.

Walter Isaacson: Eventually Virdi can no longer find replacement parts for her analog hearing aid, and was forced to change to digital.

Jaipreet Virdi: But the new pairs were quite beautiful. They were the smallest, sleekest, most inconspicuous pair I’ve ever owned. So here I had arrived at the digital age, but not without consequences. For one thing, I lost autonomy over my hearing aids. Gone with the days of me tinkering with them, taking out my box of tools to fix the regular blockage to avoid a trip to my audiologist or my hearing aid dealer for repair.

Walter Isaacson: That’s the problem with many new technologies, the problem of accessibility. And the issue of hearing aid accessibility is compounded even further when you look at the developing world. How do you distribute these technologies where users might not have regular access to electricity or replacement parts? One African company is working to change that.

Tendekayi Katsiga: Deaftronics is an organization which manufactures affordable solar powered hearing aids made by deaf people for people with a hearing loss.

Walter Isaacson: Tendekayi Katsiga is the cofounder and Operations Manager of Deaftronics. The Botswana based company was founded in response to the lack of access to affordable and consistent electric power in communities across Africa.

Tendekayi Katsiga: If you look at it, really 70% of the hearing aids that were distributed in Africa through non government organizations were only used for a month due to the problem that you can find hearing aid batteries in rural Africa. People would rather buy bread than buy hearing aid batteries. So as a result, children were cut off from school activities. Those who were recipients of hearing aids, they couldn’t use them for many days. So as a result, deaf students at that time came up with a concept to design the solar powered hearing aid so that there’s continuous use of hearing aids, and also children can participate in school.

Walter Isaacson: Deaftronics products are simple and easy to use, and they’re manufactured by a workforce that is itself 70% hearing impaired. Beyond their hardware, they’re also developing an app that helps with early detection of hearing problems for areas without access to hearing tests.

Tendekayi Katsiga: The mobile application is in use in Uganda, Kenya, and Zimbabwe. The results we’ve seen that really there is a high number of people who have never been tested before, and the response has been overwhelming. And also realized that people require hearing aids, but they can’t afford them.

Walter Isaacson: Deaftronics has sent 5,000 kids from 40 African countries to schools with their solar powered technology. Hearing aids have come a long way from the days of ear trumpets and disguised walking sticks. Their story is a secret history of every major telecommunications innovation of the last 150 years. If the point of communications technology is to connect us to the world, then there’s no better example of it than the devices that allow those with hearing loss to communicate better. And as technology is interwoven even more intimately with our daily lives, the line between assistive devices, like hearing aids, and the gadgets we increasingly rely on has begun to blur. And one day that line may disappear completely.

Walter Isaacson: I’m Walter Isaacson, and you’ve been listening to Trailblazers, an original podcast from Dell Technologies. For more information about the guests on today’s show, you can visit our website at delltechnologies.com/trailblazers. Thanks for listening.