Jungle rain is a real field recording of rain near Uxmal, in the Mexican state of Yucatán. Its source names no recordist and no date, so greensound shows neither rather than guess. It's in the public domain under CC0, and what plays here is a loop cut from the original.
Where is Uxmal?
This recording's source, on Freesound, places it at Muna, near Uxmal, in the Mexican state of Yucatán. On greensound, its catalog entry shortens that to "near Uxmal, Yucatán, Mexico," which is what this page and the mixer's info panel both show.
Why is no recordist named?
The site that hosts this recording gives only a Freesound username and an upload date, and neither one is a fact about who made the recording or when. A username isn't necessarily the person who held the microphone, and an upload date says only when a file reached the internet, not when it was recorded. Rather than treat either as a fact it isn't, greensound leaves both blank, on this page and in the info panel. This recording is CC0, a public domain dedication that asks for no credit at all; greensound credits what it can anyway, which here is only the place.
Rain or brown noise while studying?
Jungle rain carries some natural variation moment to moment, being a real recording rather than a formula, where brown noise has none by design, generated the same simple way every time. It's still cut to a loop and turned up or down by one fixed amount like every real recording here, so it matches the other sounds in level even though its texture stays its own. Which one suits a particular study session is a matter of preference.
Is it looped?
Yes. What plays is a loop of twenty to forty seconds, cut from the original recording, chosen so that no single sound inside it stands out each time it comes back around, with a 2-second equal-power crossfade baked into the seam so it can't click.