I heard green noise could make me sleep well. Sometimes I couldn’t sleep, so I listened this kind of music (maybe), I felt it’s helpful and made me fall asleep more easily.

I searched more information (website sleepfoundation.org)

What is Green noise?

Green noise is a variant of white noise that some experts suggest may help sleep. While white noise contains equal volumes of all the sound frequencies the human ear can hear, green noise amplifies the frequencies in the middle of that range.
Many people use white noise to block out ambient sounds and help them sleep better. Other “colors” of sound, such as pink, brown, and green, are also being touted as helpful for sleep. While research into the effects of green noise on sleep is limited, it is gaining popularity on social media as a useful tool to help people fall asleep faster.
(Photo: soundcloud.com/greennoisedimension/sets/green-noise-to-sleep-1-hour)