Students in the classroom need a quiet atmosphere for working. Their teacher too. Also that atmosphere or environment should be relaxing.
I know a retired teacher of the first years of education that used to talk lowly to their very young students, who need to move around, stand up, they’re swift to move, as I said…
Those students did not move from their chairs at all.
So we teachers need to create that atmosphere.
For example, not to start an activity or a presentation until everybody is attentive and at disposal for that quiet work.
What I do with kids is to keep silent, stare and gaze at each of them or at someone who is chattering with his neighbor till he gets aware of the fault and stops talking.
And I address each student without raising my voice too much.
When I want to say something special or important, I also speak low and slow, playing with eye-contact and face expressions. / Photo from: nsp4kids com