And on a lighter, darker note, Simon and Garfunkel would love this one
Just as the color white is the combination of all colors, "white noise" covers the full spectrum of sound waves. Now, here's the thing that puzzles me. Go ahead. Listen to this. The YouTube "video" has ten full hours of it:
No, there's nothing wrong with your hearing. This is black noise. The absence of noise.
This is a recording of ten hours of...silence.
This is one of the odder things I've come across on the internet. But if you ever want to listen to ten hours of complete silence, now you know where there's a recording of it.