FYI = D'oh! = No dui!
No audiophiles in this thread.
22.4 KHz is also around the threshold of producible sound from a digital recording whose sampling rate was 44.1 KHz because the audible range is half the sampling rate due to filters. Now that we have more storage on CD-sized discs, and if we're not going back to vinyl, which we should have never left, they should sample around at least 3x the current.
The audio rags used to say vinyl could produce a range up to 45 KHz. I know I could quickly tell the difference between vinyl or CD as source when listening to a cassette recording from an album no matter how crappy the playback equipment, including musac type ceiling speakers and unfamiliar source material. There's a lot of information coming from them moving magnets or moving coils riding on the vinyl that just ain't there on CD I tells ya!