NB: Contrast this with another parenting maxim that when a toddler goes suddenly quiet it is the moment you should check they are not cutting their sister's hair or drawing life-size figures on the wall with a felt-tip.
The world is louder now - just listen. Traffic, machinery, household appliances, the TV, the incessant piped muzak playing in shops, lifts and even public toilets all contrive to push up the noise level.
At home it might be the TV, stereo or computer games all competing for space in the soundscape. The advent of compact headphones means people can walk about with their ears full, replacing the noise of the world with other sounds, often at a level where hearing damage will occur - going deaf in the quixotic pursuit of sounds that will block out the noise.
In a world that is increasingly awash in sound it seems that we no longer distinguish between the natural and artificial and are resorting to shutting up children and young people in lieu of attempting to challenge the rising levels of traffic, advertising and environmental sound that invades our ears on a daily basis.
In some countries the train services provide quiet carriage where passengers are actively discouraged from talking on their phones, playing loud music or being rowdy. It is not clear whether this include children being children - but I would hope not.
Contrast this with the way museums and libraries have moved to encouraging children in their doors. Thank goodness there is no longer a funereal hush about such places and children can discover what's in them without being intimated by the shushing of the curmudgeonly.
At one time children were told they should be seen but not heard. Now it seems that we need to turn down the volume to hear them and realise that the rest is just noise.
Terry Sarten is a musician, writer and social worker. He has discovered that sometimes saying hello to a crying child in the supermarket astonishes them into silence and forgetting what it was they were upset about. Feedback email: tgs@inspire.net.nz