Snakes are pretty much deaf (notice, no ears- they have some remnant inner ear bones but mostly feel vibrations rather than true hearing) so no, I wouldn't worry about outside "noise" at all.
However, outside SCENTS are another matter- your snake will probably enjoy the variety though- just as long as no one near you is spraying pesticides, either at a home or if you're near a farm (?) as that would be dangerous health-wise.
As for humid hides, what hugsplox already posted. I've never bought one, I make my own as described. Big enough plastic container for damp moss + snake, cut doorway for snake to enter. Easy!