I have been listening to a downloaded copy of freesound.org user "reinsamba"'s 30 minutes of thunder storms for years. Literally one track.
Probably half of the "flow" time I've had has been listening to that one track. Hundreds and hundreds of loops. I'm not sure if this is a recommendation of the track or condemnation of my sanity.
>>thearr+61
Exactly that one, yes. Well, I can't view that URL from here, but that integer is in the MP3's filename. Case closed! There's a lady's / small persons's voice admonishing someone for make noise with what sounds like a screen door part way through. It's not in English that I can tell. Do let me know if you understand what they say. I'm assuming it's just "shut up, recording!"
>>verytr+(OP)
That's interesting. I use a similar trick, when there are distracting noises I put on white noise just loud enough to mask it. That then turns into the new baseline and I somehow experience it as silence.
>>verytr+N1
There is a Reply All episode about something exactly like what you describe [1]. It's been a while since I've listened to it, but it's something about how making sounds like these is a whole business with resellers upon resellers. They dive into the process and try to track down the person who made a specific recording that also had some background noise that seemed particularly weird.