Grey Noise Ten Hours
Grey Noise is a variation of white and pink noise, though not as commonly used in audio.
It is close relative to pink noise with extra energy–sound frequencies in the high and and a solid low end. Midrange frequencies are lower in intensity which makes grey noise more aesthetically pleasing to the listener than white noise. It is sort of an electric version of a natural stream or water flowing over rocks. Good for listening at low levels and masking unwanted sound in the immediate acoustic environment. Listen to it during work or sleep.