College level texts on hearing or senses might be a good place for you to look. Lots of basic info in one place. It may not be pre-chewed enough. You'll find spending some effort earns large dividends. Some is not directly related to things like THD or reflections etc. But enough is so you'll be able to put 2 and 2 together if you'll do the work.
https://www.amazon.com/Introduction..._rd_t=40701&psc=1&refRID=WQEATP0TZ07J3FYDKPMY
This is a good example of one that is worthwhile. You'll learn basics of how hearing works, theories describing how our ears/brain process sound, masking and enough to go a long way toward filtering out what matters and doesn't.
https://www.amazon.com/Fundamentals..._rd_t=40701&psc=1&refRID=2AE2H5DH68RBW971MH4P
This one is more enlightening I think, though not quite as easy as the Moore text.
Now do you have to become educated in the psychophysics of hearing just to buy audio gear? No you don't. Many of the various limits of audibility are nailed down with in reason. It is worthwhile to note it isn't like "wow, you can really hear that!" and you reduce it by fraction of a percent and the effect is suddenly inaudible. If some of the suggested limits are off of maximal limits of the best hearing humans alive, its not like you'll have a massive degradation nor that removing edge case spurious signals will make it all sound like you've never heard it before. You might barely detect .1 or .2 % distortion with test signals in just the right frequency range. It is doubtful anyone would find that level of distortion audible with music.
Basic frequency response of up to 20,000 hz within .1 db of flat, distortion below .1%, and noise levels low enough they aren't obvious won't leave much on the table if anything with music. Audiophiles aren't advancing the psychophysics of hearing. They just let bias convince them they are.
Various other guidelines people are telling you are backed up by research somewhere. They unfortunately aren't in a wikipedia of audible hearing limits.
If you don't want to learn a bit more, or don't have the time, you'll have to decide what kind of info is worth trusting. You might choose wrongly. One guideline that helps plenty with some of the more dismissible claims is people really can't hear above 20 khz. People really have to have it LOUD to hear anything above 15 khz. Whenever someone is selling you on an idea involving ultrasonic signals there is usually something wrong with their claims.