[nullc]

What you are showing is _precisely_ the effect of low-passing, nothing more, nothing less.

See the digital media primer 2 for more information on that: https://wiki.xiph.org/Videos/Digital_Show_and_Tell

If humans were able to hear audio above 22kHz (or what not) in any meaningful way, we'd expect to be be able to demonstrate that effect in carefully controlled studied and then that lack of low-passing may matter; but that isn't what the best evidence so far shows.

[yzhou]

The low-passing with a brick wall filter on 44.1KHz audio can be a bad thing sometimes, for example, pre-echo https://en.wikipedia.org/wiki/Pre-echo You won't hear the pre-echo on a 2.8MHz DSD audio.