ENT surgeon who has bilateral CIs and has been in the research field for 20+ years. This sort of stuff is cool, but there are lots of limitations at the auditory nerve interface that limits improvements to speech and music processing strategies. Crazily enough, many of these studies were done in the 1960s to 1990s and are still valid today. There are strategies that can help at individual level, but do not help everyone. Thus they have not made it to clinical use.
Software like Voicemod transforms speaking voice into a bright, robotic, or Miku-inspired digital idol tone in real time. I wonder if this would help in hearing and understanding speech better.
Author here. I'm Korean, and I have cochlear implants in both ears, which I received in a clinical trial in 2025. No one could tell me what I actually hear, so between 11 October and 4 November 2026 I ran seven psychophysical tests on myself (10,992 trials), using browser test apps that Claude built for me. I'm an amateur, so there are surely mistakes, and corrections are very welcome.
A sort of anti HN comment to say but very interesting reading, I don’t know if I have answers to any of your questions but thank you for sharing, I will read more and consider it.
This was beautiful to read. Thank you for writing it! Don’t worry about it reading like slop - your voice comes through very distinctly to me.
You mention a lot of ethics concerns; I am totally uneducated on medical ethics but I think those are pretty important questions. It doesn’t sound like you’ve had a lot of support from this startup.
I might suggest to you that you publish this on a website - GitHub pages comes to mind as something Claude or codex could do for you easily - it would let you segment this information in a way that someone who wanted to help with the medical questions could get right to that stuff, and someone who wanted to help with ethics could also jump to what they were interested in.
Either way, thank you for the write up! Your curious and open attitude is lovely.
This is interesting and I'm going to write out my thoughts for you here. Just some impressions.
Right off the bat after skimming this I'm caught up with a detail that you confirm multiple times - that you can tell literally nothing apart given any input over 70 hz. You have had this measured a few times and you definitely say that nothing is coming across above 70 hz.
Yet you are trying to hear all sorts of things that have most all of their information content above 70hz.
The Hatsune Miku music? You're hearing the bass and the kick drums and maybe some subharmonics generated in the reverberation of the higher stuff. But that is a tiny fraction of the music, and, I hate to tell you this, but that computer girl singing is all way, waaay up higher than 70hz. The beautiful sounds you are getting across are the cool synth basses of all that music. It's very modern, punchy music and the bass of that type of electronic music is very different from other classical music so whatever modulation your implants are doing to it from 70 hz down likely sounds very cool compared to a lot of other music, for sure.
But, stop- you're getting nothing by noise and wind sounds with no information differentiation over 70hz because your brain isn't demodulating that information, maybe due to something about how the implant was... implanted... or just your specific condition, who knows, but what you can do is work in the band you have.
You mention not getting human voices because the fundamentals of human voices are more than 2x where your cutoff is.
Have you tried using a program like Audacity - or - Get claude to write a script for you that takes in MP3's of modern music and slows them down 300-400 %. The music will be very slow, but it will shift instruments from higher up (pianos, horns, people's signing) down into the 20-70 hz range, and you will maybe hear patterns that are new. Did no one in the study post-op sit with you and go thru this kind of thing? You have all these external trials listed but most all of it is moot if everything above 70hz is missing and you aren't able to modify the modulator hardware.
Note that the type of rhythms in the bass of the bass synthesizers of that Hatsune Miku tracks are different that the more complex rhythms and melodies played by instruments higher up (like pianos and lead synths). (This is true for most all music genres...) Shifting those higher up things down in frequency, even if that means they play back slower, may give you an different musical experience.
Continuously pegging your implant modulation hardware with frequency content above 70hz attempting to discover something about how it interacts with your brain when you continuously get nothing but broadband noise over 70hz seems like a dead end exercise.
I mean hell, have you tried putting a low pass filter to block out on everything in the music/microphone input above 70hz just to make sure that information isn't somehow overloading the way the implant works with your brain, and maybe just causing confusion.
Lastly it sounds like you could benefit from talking with someone with a real audio / digital signals processing / electrical engineering background that can inspect your hardware directly and make suggestions because educating yourself with just GPT runs might be spinning you in circles.
For instance... you mention things like "
The logic of my test apps, which generate the test sounds and move the staircases, was checked with the Lean 4 formal verifier,"
Man... this has nothing to do with needing a 'Lean 4 formal verifier' to check your app or whatever. You need someone to sit with you and your damn hardware and work with some audio input. You need the someone that setup the original implant modular to explain the hardware mapping and filtering options to you and see if you can go back and change how that works, to get more options. You're getting some wildly mixed signals (bad pun) about how all this works, I think.
> Have you tried using a program like Audacity - or - Get claude to write a script for you that takes in MP3's of modern music and slows them down 300-400 %. The music will be very slow, but it will shift instruments from higher up (pianos, horns, people's signing) down into the 20-70 hz range, and you will maybe hear patterns that are new
You don't need to slow them down, you can just pitch shift everything into the 0-70 hz range. If there were a way to figure out how his brain is demodulating the signal, you might even get something pretty reasonable out - the essay describes sounds like cars as hissy rather than heavy.
The real difficulty is keeping genuinely inaudible frequencies (<40 hz? but who knows how his implant works) from swamping the rest, I would think.
Yeah, ordinary hearing is normally quoted as 20Hz to 20kHz, but most people are hearing mostly between 2000 to 5000Hz. If truly there was no perception above 70Hz that would lead to a very muddy and indistinguishable soundscape.
> most people are hearing mostly between 2000 to 5000Hz
That's pretty misleading, we tend to have excellent hearing anywhere in the 100 hz - 6000 hz range. Much of music and all fundamental frequencies produced by the human voice (except people with very rare whistle register abilities) is below 2000 hz. We're most sensitive to the range you're talking about because it's the most useful for discriminating between different sounds, but still only slightly more sensitive to that range than to lower frequencies.
The culture here is pretty split. Honestly, there's a sizeable contingent that will likely flame/flag you for mere use of AI. Try not to take it too hard; they don't represent everyone and I at least thought your post was a valuable addition here.
ENT surgeon who has bilateral CIs and has been in the research field for 20+ years. This sort of stuff is cool, but there are lots of limitations at the auditory nerve interface that limits improvements to speech and music processing strategies. Crazily enough, many of these studies were done in the 1960s to 1990s and are still valid today. There are strategies that can help at individual level, but do not help everyone. Thus they have not made it to clinical use.
Software like Voicemod transforms speaking voice into a bright, robotic, or Miku-inspired digital idol tone in real time. I wonder if this would help in hearing and understanding speech better.
Author here. I'm Korean, and I have cochlear implants in both ears, which I received in a clinical trial in 2025. No one could tell me what I actually hear, so between 11 October and 4 November 2026 I ran seven psychophysical tests on myself (10,992 trials), using browser test apps that Claude built for me. I'm an amateur, so there are surely mistakes, and corrections are very welcome.
All trial-level data, the analysis code and Lean 4 checks of the apps' logic are on GitHub (non-commercial licenses): https://github.com/mi-rae-lab/ci-psychophysics-data
I do not speak English. The page was translated with Claude, and I will use AI to read and answer replies, so my answers may be slow.
This is my first time visiting Hacker News, and my first post here. I don't know the culture here well yet, but I deeply respect it and support it.
It is past 1 a.m. here in Korea and I am very tired, so I need to get some sleep. I will check back around 9:30 a.m. Korean time (00:30 UTC).
A sort of anti HN comment to say but very interesting reading, I don’t know if I have answers to any of your questions but thank you for sharing, I will read more and consider it.
This was beautiful to read. Thank you for writing it! Don’t worry about it reading like slop - your voice comes through very distinctly to me.
You mention a lot of ethics concerns; I am totally uneducated on medical ethics but I think those are pretty important questions. It doesn’t sound like you’ve had a lot of support from this startup.
I might suggest to you that you publish this on a website - GitHub pages comes to mind as something Claude or codex could do for you easily - it would let you segment this information in a way that someone who wanted to help with the medical questions could get right to that stuff, and someone who wanted to help with ethics could also jump to what they were interested in.
Either way, thank you for the write up! Your curious and open attitude is lovely.
This is interesting and I'm going to write out my thoughts for you here. Just some impressions.
Right off the bat after skimming this I'm caught up with a detail that you confirm multiple times - that you can tell literally nothing apart given any input over 70 hz. You have had this measured a few times and you definitely say that nothing is coming across above 70 hz.
Yet you are trying to hear all sorts of things that have most all of their information content above 70hz.
The Hatsune Miku music? You're hearing the bass and the kick drums and maybe some subharmonics generated in the reverberation of the higher stuff. But that is a tiny fraction of the music, and, I hate to tell you this, but that computer girl singing is all way, waaay up higher than 70hz. The beautiful sounds you are getting across are the cool synth basses of all that music. It's very modern, punchy music and the bass of that type of electronic music is very different from other classical music so whatever modulation your implants are doing to it from 70 hz down likely sounds very cool compared to a lot of other music, for sure.
But, stop- you're getting nothing by noise and wind sounds with no information differentiation over 70hz because your brain isn't demodulating that information, maybe due to something about how the implant was... implanted... or just your specific condition, who knows, but what you can do is work in the band you have.
You mention not getting human voices because the fundamentals of human voices are more than 2x where your cutoff is.
Have you tried using a program like Audacity - or - Get claude to write a script for you that takes in MP3's of modern music and slows them down 300-400 %. The music will be very slow, but it will shift instruments from higher up (pianos, horns, people's signing) down into the 20-70 hz range, and you will maybe hear patterns that are new. Did no one in the study post-op sit with you and go thru this kind of thing? You have all these external trials listed but most all of it is moot if everything above 70hz is missing and you aren't able to modify the modulator hardware.
Note that the type of rhythms in the bass of the bass synthesizers of that Hatsune Miku tracks are different that the more complex rhythms and melodies played by instruments higher up (like pianos and lead synths). (This is true for most all music genres...) Shifting those higher up things down in frequency, even if that means they play back slower, may give you an different musical experience.
Continuously pegging your implant modulation hardware with frequency content above 70hz attempting to discover something about how it interacts with your brain when you continuously get nothing but broadband noise over 70hz seems like a dead end exercise.
I mean hell, have you tried putting a low pass filter to block out on everything in the music/microphone input above 70hz just to make sure that information isn't somehow overloading the way the implant works with your brain, and maybe just causing confusion.
Lastly it sounds like you could benefit from talking with someone with a real audio / digital signals processing / electrical engineering background that can inspect your hardware directly and make suggestions because educating yourself with just GPT runs might be spinning you in circles.
For instance... you mention things like " The logic of my test apps, which generate the test sounds and move the staircases, was checked with the Lean 4 formal verifier,"
Man... this has nothing to do with needing a 'Lean 4 formal verifier' to check your app or whatever. You need someone to sit with you and your damn hardware and work with some audio input. You need the someone that setup the original implant modular to explain the hardware mapping and filtering options to you and see if you can go back and change how that works, to get more options. You're getting some wildly mixed signals (bad pun) about how all this works, I think.
> Have you tried using a program like Audacity - or - Get claude to write a script for you that takes in MP3's of modern music and slows them down 300-400 %. The music will be very slow, but it will shift instruments from higher up (pianos, horns, people's signing) down into the 20-70 hz range, and you will maybe hear patterns that are new
You don't need to slow them down, you can just pitch shift everything into the 0-70 hz range. If there were a way to figure out how his brain is demodulating the signal, you might even get something pretty reasonable out - the essay describes sounds like cars as hissy rather than heavy.
The real difficulty is keeping genuinely inaudible frequencies (<40 hz? but who knows how his implant works) from swamping the rest, I would think.
Yeah, ordinary hearing is normally quoted as 20Hz to 20kHz, but most people are hearing mostly between 2000 to 5000Hz. If truly there was no perception above 70Hz that would lead to a very muddy and indistinguishable soundscape.
Wikipedia is not bad on the subject: https://en.wikipedia.org/wiki/Hearing_range
> most people are hearing mostly between 2000 to 5000Hz
That's pretty misleading, we tend to have excellent hearing anywhere in the 100 hz - 6000 hz range. Much of music and all fundamental frequencies produced by the human voice (except people with very rare whistle register abilities) is below 2000 hz. We're most sensitive to the range you're talking about because it's the most useful for discriminating between different sounds, but still only slightly more sensitive to that range than to lower frequencies.
The culture here is pretty split. Honestly, there's a sizeable contingent that will likely flame/flag you for mere use of AI. Try not to take it too hard; they don't represent everyone and I at least thought your post was a valuable addition here.