Fuck i can only hear up to 17000, it is questionable as to wether or not i could hear 18000 with better speakers at the correct volume. But at different hz of course i get different results... i can hear 18000 at 50 hz but not at 15
when taking these tests, don't forget that there's a good chance your speakers can't reproduce the tones over 18k-19k very well... I can't hear anything over 17k on my cheap shitty desktop speakers, but I can hear 19k in the studio.