I re-read it and looking more at the tests and... I think you're right but also maybe OP is confused about how the audio spectrum works in general then, because they themselves talk about this 70hz shelf in the same breath as human vocal ranges etc -- that isn't amplitude modulation frequency. But maybe there is just something here that is lost in translation or I'm just not getting the real purpose of these test measurements.

If I'm a bit more imaginative on this 2nd read of their 'experience' of these tests it seems that maybe yes, they hear 'something' at higher frequencies but it just just broadband noise- broadband noise mind you, is, all frequencies... so I was confused at how someone could say they 'don't hear anything above 70hz' and yet can somehow hear 'noise' at '2000 hz'. But it is dawning on me that the implant / associated driver hardware may simply be 'saturating' when the spectral content of audio is too large at all those frequencies, and OP can actually 'hear' something, but it just blurs into white noise when the spectral power is too high - kinda like there is a massive amount of reverb being applied to everything over 70hz.

But again they talk about their struggles with understanding voices and whatnot but if they are hearing parts of music at all then they could be hearing people' voices shifted into bands and toned down to amplitudes that helps them. Like, clinicians with experience here should be helping with this and it is kinda insane that this person is attempting to discern anything themselves.

The exposition is strange and again that could just be the translation and writing style but some of those little bits and just the way I've seen some people literally start spiraling when they start to pair-autodiadict with AI - coupled with the fact this is a medical condition and a life-altering disability - along with a few other small oddities in this post - make me kinda worried there is a lot more to this than posted and OP may need other kinds of help with their situation.