The ambient sound has been compared to rain and ocean waves.

Pink noise, a staticky sound that’s supposed to help people fall asleep, may actually worsen your rest, a new study found.

Pink noise — like white noise — contains all the frequencies humans can hear, but it plays lower frequencies more prominently. Sounds that are used for different types of brain stimulation or relaxation are assigned a color based on how their noise spectrum matches with a colored light spectrum. White noise plays all frequencies at the same intensity, and white light combines all the visible light colors.

Pink noise has been compared to sounds of rain and ocean waves. Research on its benefits for memory and sleep has been mixed.