And on a lighter, darker note, Simon and Garfunkel would love this one

I've gotten into the habit of using the various YouTube videos (well, audios, really) of white noise, gray noise, and brown noise to help me sleep. They crowd out distractions in the environment and help one to calm the mind and relax. The various "colors" of sound, as I understand it (and I'm probably wrong) are sound waves which correspond to the light waves which would manifest as the specific colors in their names.

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.

Of nothing.

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.