Cochlear Implant

Hi folks,

I just came across this project after getting my first taste for these things with the Sapien LLC Cthulhu Shield Tongue IO project.

I’m curious - how would I go about using the Tympan to recreate a very basic cochlear implant? Can the line out pins be used to deliver an electrical stimulus? Or do you guys have any other recommendations for a project like that?

Thanks for the help!

Hi, I’m not really sure what you’re asking, so I’m going to try to explore some of the ideas adjacent to your post. I think there might be a misunderstanding somewhere in here, but I’m not sure, so pardon me if I get something wrong, or go over something that you already know.

Let’s look at what components are in a cochlear implant:

Like the name suggests, there’s a portion of the device that is implanted on the inside of the skull, with a wire that threads through the cochlea. This is the cochlear implant.

For many reasons, the Tympan should not be installed inside of someone’s skull. It is really big, it is not sealed or enclosed, it heats up, and it has physical switches on it that would be made inaccessible, to name a few. Plus, you wouldn’t be able to access the 3.5 mm jacks. To be very clear-- cochlear implants are INSIDE the head. INSIDE! You would be a madman to even dream of installing your own cochlear implant!

Perhaps you were not thinking ‘cochlear implant’, perhaps you were thinking ‘signal trasmitter’?

So, the Tympan is a board for audio processing. If you look at top left portion of the image, the Tympan could replace the portion near the patient’s ear-- the part that says ‘microphone and speech processor’. It sounds like the Cthulhu IO projects are closer in knowledge area to the ‘transmitter’ portion of the image, and to the ‘receiver and stimulator’ areas in the inner image. Rather than the Tympan being an audio analog to the Cthulhu IO project, it looks to me like the Cthulhu IO project’s tongue nerve stimulator is something that could possibly take input from the audio processing of the Tympan and send it along elsewhere.

Does that help clear things up? I suspect the communication method between the transmitter and the internal cochlear implant is obfuscated, but perhaps you could find more information on it by looking up the FDA approval documents for the implant’s receiver portion.


Hi Meredith,

Thanks so much for the reply. Yeah I’m just doing some research around cochlear implants and would no way intend to implant anything in anyone!

I guess what I’m trying to figure out is how I might be able to build the functionality of a full-system cochlear implant (without the wireless power transmission, on the bench) with a project like Tympan. I guess I could use Tympan for the microphone and circuitry for the DSP but it looks like the output of Tympan is the modified audio signal?

I would then need something to take that signal and process it in to say, 20 discrete electrode channels and then stimulator module that would send electrical impulses to those electrodes correspondingly. Are there any other projects than the Cthulhu that might be suited to this purpose?

I also came across a rather cool project that takes audio input and lights up LEDs that would represent electrodes on a cochlear implant:


Hi Francis,

That LED cochlear implant project looks cool! I don’t think this group looks at cochlear nerve i/o much, but if you wanted to get the lights lighting up according to an audio ‘prescription’, the Tympan would be a good fit. I’m not a Tympan developer, but there are i/o pins on the board, and I imagine you could use them to send out an electric signal based on frequency.

To me, it seems like you might not need a Tympan at all for at least a first pass at your project, if you modified the LED implant simulator to deliver a small current instead of lighting up an LED. I think the Tympan is primarily designed to apply transforms to change sound into different sounds, though I don’t think that’s the only thing it could do.