Cochlear Implant Atlas
CI Atlas · History of the Cochlear Implant · Module 03

3Djourno & Eyriès — the 1957 first

If the cochlear implant has a birthday, it is in 1957, in Paris. A physiologist-engineer, André Djourno, had been developing induction coils to stimulate nerves through intact skin. A surgeon, Charles Eyriès, was operating on a man whose ears had been destroyed by disease and who was completely deaf and facially paralysed. Together they did something nobody had deliberately done before: they laid a wire directly against the stump of the auditory nerve and drove it with Djourno's coil. The patient heard. The sounds were strange and speech was beyond him, but the principle was proven — and the modern history of the cochlear implant starts here.

FThe 1957 operation

The patient had lost both ears to bilateral cholesteatoma and the surgery that followed, leaving him totally deaf with a facial-nerve palsy. Eyriès was attempting a facial-nerve graft. Djourno, who had been working on stimulating nerves by electromagnetic induction, proposed that while the field was open they place one of his coils so as to stimulate the remaining auditory nerve. They did — and the patient reported hearing sounds in time with the stimulation.[2003]

THow the device worked

The design prefigured every implant since. An external coil generated a varying magnetic field; an implanted coil under the skin picked it up by induction, so power and signal crossed the intact skin with no wire through it — the same transcutaneous principle used by modern devices. A wire from the implanted coil carried the current to an electrode placed against the auditory nerve. There was no sound processor and no attempt to encode frequency: the device simply delivered a stimulating current to the nerve.

1957 — the first stimulation of the human auditory nerve

skinExternal coiltransmitterImplanted coilreceiver, under skinAuditory nervewire on the stump“a cricket”

In Paris in 1957, the engineer André Djourno and the surgeon Charles Eyriès placed an induction coil and a wire directly against a deaf patient's auditory nerve. An external coil drove it through the skin. The patient heard sounds — likened to a cricket or a roulette wheel — and could tell some rhythms apart, though not understand speech. It was crude and the device soon failed, but it was the true origin of the cochlear implant: proof that stimulating the nerve directly could produce hearing.

FTWhat the patient heard

The percepts were rudimentary but unmistakable. The patient described sounds like a cricket or a roulette wheel, and — crucially — he could distinguish some rhythms and report changes in the stimulation. He could not understand speech. By any modern standard the result was minimal, but the point was categorical rather than quantitative: a profoundly deaf human being had been made to hear by direct electrical stimulation of the auditory nerve. The thing was possible.

TWhy it ended — and what it started

The device failed within weeks, and a second attempt also failed; the primitive materials could not survive the body, and the collaboration between Djourno and Eyriès broke down. The French effort petered out. But a published account — and word of mouth — carried the idea abroad. In Los Angeles, a deaf patient reportedly brought a report of the French work to the otologist William House, who recognised its significance and resolved to build something a patient could keep and use. The torch passed from Paris to California.

CThe question of credit

For decades the cochlear implant's origin was popularly attributed to the American pioneers, and the 1957 French work was nearly forgotten. Later historical scholarship — most influentially Eisen's 2003 account — restored Djourno and Eyriès to their place as the true originators of direct auditory-nerve stimulation in humans. It is a useful reminder that the “inventor” of a technology is often a chain of people, and that priority can be obscured by language, distance, and the failure of a first attempt.[2003, 2013]

What survived from 1957 — and what had to be added

Feature
1957
Modern
Transcutaneous coil-to-coil link
Implanted receiver-stimulator
Direct electrical nerve stimulation
Durable biocompatible materials
Multichannel intracochlear array
Sound-coding processor

Strip a modern implant to its principles and the 1957 device is recognisably its ancestor: power and signal still cross the skin by induction, an implanted receiver still drives the current, and the target is still direct stimulation of the auditory neurons. What sixty years added was not a new idea but durable materials, a multichannel array to exploit cochlear place, and a sound processor to code speech. Djourno and Eyriès built the skeleton; everyone since has added the flesh.

Next, the man who took the French spark and spent a decade turning it into a wearable device against the doubts of his peers — William House and the single-channel implant (Module 4).

Case 1.3 · The transcutaneous link
A trainee examining a modern implant notes there is no wire or plug crossing the skin — power and signal somehow pass through intact skin to the internal device.

Which 1957 design feature does this modern arrangement directly inherit?

Self-assessment — Module 32 questions
Question 1 · Foundation

What did Djourno and Eyriès achieve in 1957?

Question 2 · Trainee

Which feature of their device survives in every modern implant?

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