Hi,
I read the link - from 2002. There was a proposal by Neil Young stating that you don't need 24bit audio since 16bit audio can contain a tone at -105dB compared to the signal to noise capable by 16bit audio (96dB).
(
https://web.archive.org/web/20120307015559/http://people.xiph.org/~xiphmont/demo/neil-young.html)
When you examine the audio file provided, to encode that sine wave at -105dB you need 5bits peak from the 16bits available, and you can actually see the sine wave, albeit blocky, in the signal using audacity.
Even the benchmark caveat the statement about jitter being audible in the same article :
"Jitter can only be considered totally inaudible if the worst case jitter induced sidebands are at least 23 dB below the A-weighted system noise.
Above this level jitter may be audible or it may be masked by the program audio"
I am always sceptical when there are claims of signals being heard much lower than than the best hifi S/N of approximately 110dB. Frequencies seen on a spectrum analyser are not always representative of real world hearing and as usual, if someone is selling something, there is always poetic licence in their text to some extent.
Regards,
Shadders.