raise you hand if you can still hear 40Khz

[deckeda]

mikebw wrote:
[quote=Rolando]
I used to torture my kids with a 20K tone, loud.

I couldn't hear it, but they would come out and say "What is that"

At max volume, I still could not hear it, but I could feel the sound pressure in my ears.

I experience the same thing. Feeling is believing!
Yet another example where measured specification doesn’t reveal much. We sense sound in ways other than what our ears transmit. You can feel low frequencies fairly easily because it’s a longer waveform. Hard to “measure” bass impact.