I'm very interested in what works for you. I have the same problem. In my case it's hearing damage from COVID. One of my ears has substantial high freq hearing loss and this ear also hears a lot of distortion and "grain" that isn't there. My doctor tested my hearing and says it's better than average, but the test is NOT hifi. It tops out at 6kHz. The bad ear doesn't hear certain cymbal sounds any more and it seems like my brain cranks up certain frequencies from the good ear to compensate, which results in sibilance. The same thing happens with any speaker in any room, but not with headphones! I think it's because of the room being removed and there's no cross feed between the ears.
