[cronix]

I was expecting to just hear white noise. Isn't that what all frequencies is added together, like the color white is all colors added together?

[robmiller]

White noise is equal energy across all frequencies linearly. Sounds hissy because there are more frequencies included within each musical octave as you go higher.

A more even-sounding spectrum is pink noise which is equal energy per base 2 logarithmic bandwidth. Sounds like a waterfall.

[Schwolop]

You should look up 'black noise' on the chart. It's music generated using MIDI so that the printed score maximises the quantity of black ink used. The "music" aspect is like listening for the whitespace in a sea of sound.

http://everynoise.com/engenremap-blacknoise.html