Hi Z10. I think it would be more accurate to say that we have diminished hearing rather than lost hearing. If you lose your sight, no glasses prescription will work. Fortunately for us, we can hear some frequencies that we thought were lost, with amplification.
I was very surprised to find out that headphones don’t have a flat frequency response. Look at the curve for the fairly high end phones I use here: https://www.innerfidelity.com/images/HiFiMANHE4002014.pdf
I REALLY want to find a pro to discuss this with. Standard audiograms top off at 8kHz. And the measurements are spaced very widely. So, I guess I would first need to be tested at more different frequencies above 2kHz? I don’t know. Then, maybe I need to find something called a parametric equalizer that I can customize to a high degree, maybe? I have these variables. My hearing may have peaks and valleys and the headphones will have different peaks and valleys. If I do 1 big general treble boost, and my headphones have a peak in that area, can I possibly damage my hearing? Don’t know.