I'm a fan of ambient noise and the likes of Brian Eno. I'm somewhat fearful of using the same tones for _very_ long periods of time. The inner ear doesn't tolerate these well (especially white noise), nor does the brain. In moderation however, bring it on. Thanks for the links.
I had a much harder time finding info about the mechanism I reported than I would have thought. I think perhaps I was wrong and I appreciate the prompt to research further.
Even at low levels, anything droning I _theorize_ (for the moment) must _habituate_ the listener (e.g. cricket song). I thought I understood that physiologically, such droning caused the tiny hairs of the inner ear to either die or become less sensitive. The brain filters "noise" I understood. Again, I cannot seem to find evidence of this at low sound pressure levels(~volumes), so my reasoning may be a byproduct of some pseudoscience.
I understand that tinnitus suffers sometimes use white noise to habituate themselves to the ringing they perceive, and that this reportedly improves their symptoms. However, this conclusion seems incomplete to me. I think there is habituation happening, but I suspect it's: (1) a desensitization to nearly all frequencies (white noise = broad spectrum) and (2) frequency masking. (1) would be sacrificing the ability to perceive across the spectrum in order to minimize the effects of "the ringing" which is only sometimes physically present. (2) (masking) fools the brain/ear into not hearing something that "really" (psycho-acoustically, in this context) is there. Enough of my theorizing though.
Most of what I find suggests that "noise" by definition is loud and only sometimes unwanted. I take issue with both over-simplifications. lol.
I first learned about the concept while studying to become an Audio Mastering Engineer. I gave up before making it to that level, though.
The concept of "central gain" is pretty interesting as a topic of research in this field.
To be honest, I'm happy to learn there is little evidence of droning causing damage at low SPLs; I used to sit on a data center room floor with a direct line of sight to hundreds of computer racks. :-)
Playnoise.com is an HTML5 noise generator that supports Brown noise (as well as pink and white). I find it much less harsh than white noise for any period of time.
