Thanks for the link.
That article presents strong evidence why it is important to filter signals above the audio bandwidth when recording so that they do not create alias artifacts in the audible portion of the spectrum.
To quote from the study itself:
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...and points out that even if ultrasound be taken as having no effect on perception of live sound, ... its presence may still pose a problem to the audio equipment designer and recording engineer.
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And errors in the analysis that may appear to be audible phenomenon , but in reality are a measurement artifact:
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...even if a spectrum had no content above 20 kHz, it might nevertheless look as though it did because of the adding-up of "bumps" from energy below 20 kHz. I call this putative phenomenon "window-splatter."
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