Char_lotte and Overdose, given your recent tests, I have no doubt that your hearing is acceptable for your age, but like most things in life hearing deteriorates over time.
http://www.roger-russell.com/hearing/hearing.htm
I am not rude enough to ask your age, but unless you are superman (or woman) it is likely that your hearing has declined along the graphs on the link above.
I have spent a longtime equalizing the response of my system and listening room using measurement mics and REW - give or take a few dB, it is flat to well over 22KHz - but I can't hear a damn thing over 14KHz (I am 50). The only beneficiaries are my teenage kids and the dog.
An interesting question for those who follow subjective reviews of equipment - should magazines publish the age of the reviewer so that the readers can make allowance for the fall-off in hearing?
For example, if the reviewer is over 30, it is very likely that he won't be able to hear the dreadful splashy HF at 18KHz from some ghastly piezo tweeter. But there again, since HiFi is not a hobby of the young, if the reviewer can't hear it, and the buyer can't hear it - does it matter?