It’s been proposed (sorry that I can’t dig up the reference) that we humans in our earlier days formed bonds amongst ourselves through mutual grooming and that these grooming circles were limited in size to about 50.
It’s also said that, as we evolved, our hands became far too, well, handy, to fritter away in grooming. So, our ancestors came to maintain their social bonds by inventing speech and yammering at each other whilst they were using their hands to make tools, stir pots, change diapers, whatever.
It turns out, in fact, (again, sorry I can’t dig up the reference) that our conversations are still dominated by inconsequential blather, what some might call “noise.” This noise, as you point out, is ideally suited to maintaining social bonds.
What is interesting about all this is that what with all the twitter posts from mobile phones and keyboards is that we apparently have returned to using our hands to maintain social bonds. Perhaps its because we don’t want to waste our voices on such mundanities.