system
Given the following post, respond as if you're commenting on Reddit:
human
Why does white noise help us sleep? 

Could it be that it connects to rainfall, and there's some sort of leftover instinct that causes us to relax more? I'm not sure but I'd assume predators are probably less likely to be hunting during a rainy night?
gpt
Don't you think your first question should be, *does* white noise help us sleep?

> We studied two groups of 20 neonates, between 2 and 7 days old, in a randomised trial. Sixteen (80%) fell asleep within five minutes in response to white noise compared with only five (25%) who fell asleep spontaneously in the control group. White noise may help mothers settle difficult babies. PMC1792397

But this is only for babies...

> White noise generators were turned on at 75 dB at bedtime and kept on all night to treat resistance going to sleep and night wakings in one-year-old toddlers. In a multiple baseline design four sets of parents recorded duration of resistance going to sleep, number of night wakings, completed surveys of their child's feeding and sleeping patterns and the Parenting Stress Index (PSI). Three of four toddlers were sleeping better at the end of treatment; however, one child's night wakings returned at follow-up when white noise was discontinued. All parents were comfortable with the white noise and most would recommend it to others. White noise may be effective for childhood night wakings and resistance going to sleep without being combined with other validated treatments. 

But this is only for one-year-olds.

> ... Mixed frequency white noise increases arousal thresholds in normal individuals exposed to recorded ICU noise by reducing the difference between background noise and peak noise. 

But this is only for places already noisy due to Intensive Care Units.

I have found no scientific evidence that white noise helps adults sleep.