About the difference of “cars passing” and “birds chirping”, I think there are two axes to it: translatability and variability.
I expect translatability from children (lots, even as background sound), cars (less) and birds (some, depending on the bird). It’s something about ease of sorting the auditory information.
(And in the context of a mini-map nim described, it would be cool to map out the physical limits of the heard area.)
But noise variability is another matter. When we talk about silence, what matters more—the intensity of sound or it’s spectral parameters? There’s at least one classification of noise (for example, https://en.m.wikipedia.org/wiki/Colors_of_noise ). I can’t hear the difference between, say, white and pink noise, and I’m like 90% sure they have indistinguishable effects on health and cognition, within “not loud doses”). But at least it’s some quantitative way to describe it.
About the difference of “cars passing” and “birds chirping”, I think there are two axes to it: translatability and variability.
I expect translatability from children (lots, even as background sound), cars (less) and birds (some, depending on the bird). It’s something about ease of sorting the auditory information. (And in the context of a mini-map nim described, it would be cool to map out the physical limits of the heard area.)
But noise variability is another matter. When we talk about silence, what matters more—the intensity of sound or it’s spectral parameters? There’s at least one classification of noise (for example, https://en.m.wikipedia.org/wiki/Colors_of_noise ). I can’t hear the difference between, say, white and pink noise, and I’m like 90% sure they have indistinguishable effects on health and cognition, within “not loud doses”). But at least it’s some quantitative way to describe it.