Silent treatment

As long as I'm on the subject of environmental effects on people, what about the noise level that saturates our ears? I live not far from a highway, so it is never very quiet, but you have to get very far from a city to avoid electric hums and noise from cars and radios.

Camping is not always an improvement. For some reason mosquitoes seem exceptionally loud in your tent, and if your camping trip turns out to be in the middle of a 13-year cicada eruption you might as well be listening to trucks on the other side of the fence. (And that amorous couple made themselves heard afar, at intervals.)

A quick search doesn't turn up anything obvious about the effects of low levels of noise on behavior. Moderate levels (80 or 103dB) on mouse neurons, yes, but I suspect low level effects would be small enough to require a large population study=$$ and a lot of measuring small behavior differences=$$$. (If low noise level effects were large, we'd have noticed it quickly.) There's a JAMA article that I can't get at in the first hundred references, but nothing else that seemed relevant to the question. And is white noise the same as distant machine noise, or a 3600Hz hum from bad fluorescents, or noise in the same frequencies as communication? (A fool can ask more questions than a wise man can answer...)