White noise

Yes, there are from various colours (white, pink, brown,..) with slightly different frequency of noise.

I personally find rain sounds the most enjoyable.

There is also 40hz binaural beats which are interesting.

I've never heard of brown noise.

I can't stand white noise, it hurts and I run away screaming

no I suffer tinnitus - so use music all day long as distraction.

the sound of rain (not the wet stuff itself) I love and use rain and thunder playlists on an echo speaker - to fall asleep