When we look around in any crowded place where mass of people from different ages gathered, we might reach to this conclusion: how easy for adults nowadays to keep their children quiet in a crowd.
Years ago, there were people who easily disturbed by the (annoying) voice of little kids. How the kids cry, whine, sulk, or even shout near them although the kids were not theirs, might drove them crazy.
But adults nowadays could still hang out in public while bring their kids together with them, without getting worry their kids might cause any voice polution to the public. The noise cancelling trick? Just give any gadget to each of their kids, I bet no sound could be heard from the little group.
I witness this a few years ago in an airport. The kids just litterally sat on the floor playing with their gadgets, while waiting for mommy taking a queue to withdrawn money, and daddy taking zoom-in-pictures (haha!) of the kids with his DSLR.
Perfect potrait of a family in public? Not to me. If only raising kids is that easy.