Have you tried matching a stereo to your hearing?

The "perception curve" is more difficult. We hear with our ears, and listen with our minds.

Mceljo - Speaker might have perfect frequency characteristic measured with individual tones but horrible sound (phase shifts, wrong harmonics summing).

Unless the hearing change in one's ears was a sudden change, the person would hear the normal for them sound from perfect system, becaue only a correct to real system would sound to them, normal.
Any change to compensate would sound bad to the person. It would take quite a special person to want to listen to the distorted system to supposedly hear a normal sound of music as heard by non damaged hearers.It COULD be possible, but it would be crazy as hell... IMO.
However, some folks who enjoy moving coils with the tilted up treble are, in effect, doing just that.

Elizabeth, with all due respect, I beg to differ. Don't many use different corrective lenses to compensate for different viewing circumstances? Don't many listen in the dark? Why not hear things the way they were meant to be heard, rather than in an otherwise distorted fashion, when a remedy might be readily available? I suspect customizable equalization might be a better route, than trying to find a distorted system to compensate for human error. Of course customizable high fidelity hearing aids might be the best remedy.