Today, February 25th, is a special day. We’re celebrating International Cochlear Implant Day, a day that commemorates the anniversary of the first successful cochlear implant surgery—a milestone that transformed what was possible for people with profound hearing loss.
But to understand why that moment matters, we have to go much further back in history. The story of the cochlear implant didn’t begin in an operating room in 1957. It began with humanity trying to understand hearing itself.
Welcome back to Can You Hear Me?, a podcast about hearing, hearing loss, and everything in between. To celebrate International Cochlear Implant Day, I thought I’d release a special episode about the history of cochlear implants.
To understand this story, we need to rewind thousands of years. The earliest written reference to hearing loss is found in the Egyptian Ebers Papyrus from 1550 BC, which described remedies for “ears that hear badly.” It suggested treating hearing loss with mixtures of olive oil, ant eggs, red lead, and goat urine. Historians today speculate that the olive oil was used to soften earwax, but the other ingredients’ use is unclear at best and dangerous at worst.
Fortunately, our understanding of hearing improved significantly over time. In the 1500s AD, the Renaissance brought increased interest in the human body. Bartolomeo Eustachi, an Italian anatomist, first detailed the ear’s anatomy, and the Eustachian tube, from the middle ear to the side wall of the upper throat, is named after him.
The real groundbreaking discovery came from Alessandro Volta, inventor of the battery. In 1800, he performed an experiment on himself. He inserted two metal rods into his own ears and connected them to a 50-volt battery. He described the sensation as a “boom within the head,” followed by a sound like “thick boiling soup.” Volta proved that the auditory system could be stimulated with electricity. The challenge for the next 150 years would be turning the “boiling soup” into speech.
Fast forward to the 1950s. We finally had the electronic components and surgical techniques to internally stimulate the ear with electricity. In 1957, French pioneers André Djourno and Charles Eyriès performed the first recorded implant. Their patient was a man who had lost his hearing due to bilateral cholesteatomas, or cysts in the middle ear. They routed a wire directly onto his auditory nerve. International Cochlear Implant Day actually commemorates this moment, even though it wasn’t technically a cochlear implant because the wire wasn’t routed into the cochlea itself. But, I’ll give it to them. When they turned it on, the patient wasn’t able to understand words or differentiate meaningfully between pitches, but he could identify rhythms.
It was a proof of concept, but internal politics and technical failures led them to stop their work. The torch then passed across the ocean to Los Angeles, to a man named William House.
House is often called the “Father of the Cochlear Implant.” While we in the 2020s know that cochlear implants are incredibly successful, with more than one million implanted to date, in the 1960s, the scientific community was incredibly skeptical. Many believed that the human ear was too complex to ever be mimicked by a machine.
House ignored the critics. In 1961, he developed the first clinically practical cochlear implant. While it was only single-channel, meaning it used a single electrode to broadly stimulate the cochlea, it laid the foundation for future designs. In 1962, the Stanford University team of otolaryngologist Blair Simmons and engineer Robert White implanted the first multichannel cochlear implant, featuring six electrodes to exploit the fact that the cochlea has spatially-organized hair cells that are sensitive to different pitches. By developing an implant with multiple electrodes, Simmons and White could stimulate different parts of the cochlea, which the brain perceives as different pitches.
The torch was picked up at the University of California, San Francisco (UCSF). In the late 1960s, Robin Michelson and Melvin Bartz began constructing devices using biocompatible materials—materials the human body wouldn’t immediately reject. By 1970 and 1971, Michelson teamed up with Robert Schindler and Michael Merzenich to test these implants on a small cohort of four patients.
Their results, as well as those of many others, were presented in June 1973 at the first international conference on electrical stimulation of the acoustic nerve as a treatment for profound sensorineural deafness in humans. By this point, the term “cochlear implant” had been definitively introduced into the medical literature.
As the 70s progressed, a new challenge emerged. While these single-channel implants were showing promise, allowing recipients to hear environmental sounds and helping with lip-reading, they still couldn’t provide clear speech. The race was on to create a clinically-viable multichannel device that could hit different parts of the cochlea at once.
Over in France, Claude Henri Chouard developed a complex system with seven electrodes, each requiring its own separate opening in the cochlea. It required a much more complex surgery, but it proved that multiple frequencies could be identified by the brain. Meanwhile, in Australia, Graeme Clark was working on his own version. He was convinced that single-channel stimulation would never be enough for speech, and rightly so. He spent years studying how to thread electrode arrays deep into the inner ear without causing damage. By 1978, Clark implanted his first multi-electrode prosthesis, which would eventually become the first successfully commercialized multichannel system under the company Cochlear.
By 1977, an independent evaluation known as the Bilger Report provided the validation the field desperately needed. It confirmed that cochlear implant recipients were scoring significantly higher on tests of recognition with their devices turned on. They concluded that while single-channel prostheses worked, the real future lay in multichannel technology. This conclusion actually annoyed William House at the time, as he felt the researchers were jumping to theoretical conclusions before the hardware was even fully wearable.
Unfortunately for House, the future of cochlear implant technology would be dominated by the multichannel single-wire electrode initiated by Simmons and White and implanted by Michelson’s team in 1974.
As the 70s turned into the 80s, the cochlear implant was no longer constricted to the lab. Researchers across the globe proved it had clinical translatability, but to reach the masses, they needed the backing of the ultimate gatekeeper: the FDA.
Finally, in 1984, the history of hearing changed forever. The FDA officially approved the 3M single-channel cochlear implant designed by House for use in adults. This was a monumental first—it was the first time a medical device had ever been approved to replace a human sense.
But House’s CI didn’t stay for long. While the single-channel device was technically first over the finish line for FDA approval, the multi-channel systems pioneered by Graeme Clark in Australia and the Hochmairs—other CI researchers—in Austria were rapidly gaining ground. These devices weren’t just letting people hear that a door had slammed or a dog was barking; they were beginning to pull the curtain back on the nuance of human speech. In 1985, the year after House’s CI was approved, the Nucleus 22, named for its revolutionary 22-channel design, from Cochlear Limited received FDA approval, marking the beginning of the end for single-channel systems.
By the late 1980s, the focus shifted toward the most vulnerable and potentially the most benefited group: children. In 1990, the FDA lowered the age of implantation to just two years old. This was a turning point that brought both incredible hope and intense controversy. While parents of deaf children saw a path for their kids to enter the “hearing world,” the Deaf community began to voice deep concerns. For many who communicated through Sign Language and viewed deafness as a culture rather than a disability, the implant was seen as a threat to their identity—an attempt to “fix” something they didn’t believe was broken.
Nevertheless, progress with cochlear implants continued. This period of the 1990s and early 2000s became an era of refinement. The external processors, which used to be the size of a bulky walkman worn on a belt, began to shrink until they could fit discreetly behind the ear. Engineers started implementing “speech processing strategies,” which are essentially the software algorithms that translate sound waves into electrical pulses. They realized that sound perception now had more to do with how the electrodes were utilized than how many there were.
Today, we are in the era of “intelligent” hearing. Modern implants use AI to filter background noise and Bluetooth to stream audio directly from smartphones. We are even seeing “totally implantable” designs in clinical trials.
From the olive oil and ant eggs of the Ebers Papyrus to the sophisticated devices we have today, the journey of the cochlear implant shows us that humanity can do anything it puts its mind toward. To date, more than one million people have regained hearing with a cochlear implant, with millions more to come.
And with that, I’ll wrap up the seventh installment of Can You Hear Me? This is Rishi, and I wish you a happy International Cochlear Implant Day.