High Frequency hearing loss?

Curiosity got the better of me a few days ago. With active crossovers, I am able to use 50^th order 300dB/octave slopes - my ‘unusual’ system configuration accommodates something like this quite easily with super tweeters

As an experiment, I progressively used higher crossover points and a fairly high listening volume, the other amps controlling mid & bass below the crossover frequency were switched out of circuit. This was not music and obviously quite annoying to listen to, however all I was trying to do was see what I can still hear above set frequencies and if anything at all is audible beyond 20khz or on a CD

Album used for this: Tony Joe White ‘Closer to the truth’ which is very well mastered, contains a lot of hi-hat and the metallic ring of cymbals. I also have it on LP and CD to be able to compare which I did in ‘real time’ with volumes equalised. All the frequencies below are the lowest level permitted by the crossover, upwards to infinity and beyond as they say…

With CD –

18khz+: treble is clearly heard and slightly ‘brittle’ (when switching/comparing to the LP)

20khz+: its still there, reduced in volume

22khz+: Nothing at the listening position, a slight ‘tizz’ on hi-hats audible with my ear close to the tweeter (maybe even a brick wall crossover still bleeds upwards a bit from <20khz?)

25khz+: nothing I can hear

With Vinyl –

18khz+: treble sounds clear and quite ‘shimmering’

20khz+: still clear, slightly less reduction in volume than the CD ie a bit brighter sounding

22khz+: more audible than the CD from the listening chair. Quite a lot still going on but pretty low volume & subtle

25khz+: very slight occasional ‘sssz’ sound - only with my ear very close to the tweeter and only on the high percussion & LP ‘pops/clicks’. To all intents and purposes therefore, nothing much to hear

(by the way, slightly audible hiss from the Reflex M is at a lower level than surface noise so irrelevant once the needle hits the disc)

With vinyl playback, whenever I return to full range listening but switch out frequencies above 20khz, the music becomes slightly flatter and duller. I don’t think it’s imaginary. With everything back in circuit, it all sounds natural and immediate

Conclusion: Maybe my hearing has not deteriorated as it’s meant to be… yet. The higher frequency response on an LP is somehow audible above 20khz even though we are supposed not to hear it, especially at my age and may be contributing to the ‘airier’ and more natural sound that vinyl possesses? The CD high frequencies sound subtly different to vinyl and definitely die off above 20khz (I anticipate the Majestic smoothing the brittleness though…each type of cartridge/DAC will naturally vary so it’s virtually impossible to do a true comparison)

None of this is scientific of course but thanks for reading this far !

I am back listening to music as SWMBO is away for the weekend and have a lot to get through (must remember to brush the cobwebs off the TV by Sunday evening )