Science

Having read the NYT article (with the PNAS paper still not available through a certain hub), I think a useful analytical framework would perhaps be to think of silence as a negative space. E.g., take some background noise (this could be the environmental noise averaged over some time scale) at certain overall intensity as "zero" (or reference level), then complete silence will have the same frequency content as that background but with negative intensity. From there one can start talking about various forms of "partial silence" as different spectral compositions of negative intensity. I'd even posit that some of the illusions they discovered would work in a similar fashion with positive intensity boost as well (e.g.two disjoint boosts vs one sustained boost). It is probably more about the frequency content than the intensity relative to the reference level.

I agree with ya. I can hear it whenever I intentionally seek it out, even when it's relatively loud out there. I tend to think of it as some baseline intensity (at some extremely high frequency/frequensies I've tried but yet to pin down) my brain perceives, that gets washed out more as external stimuli become stronger. This is partly what prompted me to speak about a reference level of intensity distribution over frequency (and therefore a power spectrum if you will) in the other comment thread. Normal brains have a reference level that adapts to the environmental average. Those of us with tinnitus have some nasty spikes at high frequensies. "Hearing silence", I speculate, is more of a response to a changing reference level -- some of the responses will be the brain compensating for the change and thereby inducing acoustic (?) illusions reported in this work. A tinnitus brain will respond to a receding reference level by focusing again on those nasty frequency spikes.