I was sitting in my greenhouse tending my plants when it started to rain, I have a corugated PVC roof, so you can imagine how loud it sounds during a good downpour

 

a thought occured as it started to rain drop at a time and then gradualy more and more until it was impossible to hear the lightening monitor.

 

at what point from tap tap tap, to the full roar of white noise, is the transition made?

 

when does it cease to be individual tapping sounds?

Good question!

 

I've no idea of an answer but conjecture is always good.

 

Possibly when the sound is coming from so many sources and directions that the wave pattern that is formed is so screwed up that it's impossible to work out nodes and antinodes or to be able to distinguish one source amonst the many.

 

Have you ever noticed that concentrating on white noise can make it seem much louder? In a silent room I can concentrate on the tiny noises generated in the ears to the point that it seems almost deafening. Maybe it's more a function of the mind rather than a physical thing?