Apparently the school thinks that a whistle is “too aggressive” and could leave the children “afraid of noise”.
Last time I went past a school playground there was plenty of noise.
The alternative is for the teacher to raise a hand. As if the children are all going to be looking in the same direction. And if there’s an emergency?
We are in danger of bringing up a generation of risk-averse children who will be frightened of their own shadows.