First of all, yet again, you are assuming that there is some well established standard for "what quantities of jitter cannot possibly be audible". In fact no such standard exists. (Although a few tests have shown that, under certain specific conditions, relatively high levels of jitter may be inaudible.) Your second assertion is technically incorrect... although, yet again, you persist in describing "inaudible levels" as if such a clearly established standard actually existed. (When you're talking about things like jitter sidebands, which occur at audible frequencies, there is no such thing as "inaudible", there is only "too far below a specific noise floor to be heard".) Start with 100 watts of pink noise.... Now add 1 watt of pink noise.... You will find that the added pink noise, spread over the entire spectrum of the original noise floor, will result in an inaudible rise of a tiny fraction of a dB in the noise floor.... Now, start with the same 100 watts of pink noise.... And add 1 watt of a pure 440 Hz sine wave.... You will find that the 440 Hz tone, at exactly the same level as the added pink noise, but limited to a single frequency, will result in a clearly audible tone.... Your last one is easy..... Up until recently "it was well known" that "the range of frequencies audible to human beings went from about 20 Hz to about 20 kHz..... Until recently published test results proved that humans can actually hear as low as 10 Hz.... (And, now, knowing that one end of the "well established range" was wrong, I'm not sure how much faith I place in the "well known limit" at the other end.) https://www.ncbi.nlm.nih.gov/m/pubmed/15273023/ https://www.sciencedaily.com/releases/2015/07/150710123506.htm Note that, in the article in Science Daily, while an MRI was used initially, "All persons concerned explicitly stated that they had heard something --".