Scientifically, the experiments behind 20Hz to 20KHz hearing range are vastly misunderstood by audio enthusiasts. Women in their 40s can hear 5-10dB better than men in high frequency range. Teenagers can hear significantly higher frequencies than adults, because their ears have smaller vibration receptors which fall off as we get older. Most humans who can hear frequencies up to 12Hz in ideal laboratory conditions.
So as you can see, 20Hz to 20KHz is not a scientific law, it is merely an averaged-out range over multiple test subjects. There are many people with demonstrable hearing abilities outside this range.
As a research engineer, I can say with certainty that if you include frequencies that you cannot hear but you can feel in air cavities of your body the 20Hz-20KHz range will need to be extended significantly. For example, I have two industrial-sized subwoofers and playing a 9HZ tone you can feel the vibration in the air cavities of your stomach. It has also been proven by research papers that constantly playing ultrasonic frequencies in the background can induce nervous behavior in people. There is a paper which shows that >22KHz tones can affect brain activity.
So the bottom line is that trust your ears! If you can hear something in a blind A/B test, it is real. As a rule of thumb, to really appreciate 24bit / 96KHz sound recordings you will need a system capable of affecting air-cavities using massive subwoofers and a tweeter capable of up to 50KHz range like the one found in Adam AX / SX series monitors. If you are listening to headphones or small speakers which cannot affect air-cavities, 16bit/44KHz is fine.