What you're hearing
Pink noise loses a little energy with each octave up, so it sounds more even to the ear than white noise: closer to steady rain or wind in the trees than to a hiss. If it's too bright, try brown noise; if you want more edge, white.
It's made in code, so it has no seam and nothing in it changes. It's also in the Starship sleeper starting point, far off in front of a ship's hum. The sleep timer can fade it out after 15 to 90 minutes.