I didn't mention just pitch shifting alone without speed change as depending on how that is done it can introduce artifacts. So just slowing things down like an oldschool tape player is the most 'pure'.
Any computer sound card will high-pass anything over about 16-18 hz and thus new lower stuff won't swamp, and it seems like his implant amplifier does indeed deal with low frequencies because he mentions using an 18hz tone to keep the device key'ed on.
Another thing then to mention would be 'binning' audio that has been pitch shifted own using notch filters / comb filters. Because it is possible that however the implant is wired could use some band gaps to help his brain 'decode' things more clearly and less muddy.
Again, all this is simple shit and I find it really surprising that there isn't someone to help run these tests on hardware with this person, and their blog post here has this very strange rabbit hole feel to it and I can't tell if it is because there is a lot lost in translation, or if there is a lot more to this that is coming across in translation... or if this person in being led down some near-AI-psycosis and is struggling because they simply don't have someone to sit with that can help.
It all comes off to me as very, very strange.
That is definitely the weirdest part to me. It is supposed to be a trial for this new implant right? So why isn't the company actually working with them on it? Like how is just telling someone do more therapy acceptable here? Studying their brain's reactions to the stimulus the implant is actually generating seems like something that should have already been done.
I would think you could take the audio processor out of the loop and run diagnostics on the implant itself using an EEG to determine how the brain is responding. They test the hearing of newborns with the tech, you don't need to "trust" a person or even need them to be able to communicate. Its right there in the data.
Based on my read of everything it feels like there is some issue with the implant sending electrical signals, but the nerve not actually picking them up and sending them on. Perhaps related to the original reason for the hearing loss. And the company should want to dig info it more. I know I would if it were my tech.