I remember that there was some pseudo-religious society called something like the Bene Gessirat in the "Dune" books by Frank Herbert. They were a sinister lot, with special powers and some horrible habits. One of the things they did was control people by the power of their voice.
Much as I do as a teacher.
Much as I did as a parent.
I remember that once, in a furious rage, I shouted at my infuriating toddler so loudly that she fell over backwards. "Not Good", I thought, and decided that it would be better if I changed tactics. So, for a while, I made myself speak softer and softer, the crosser and crosser I felt. Then my children started saying "Mummy, please don't whisper at us".
I use silence as a tactic quite often as a class control mechanism when teaching a chatty, fidgety, inattentive crowd. Like today's samba class. I stopped explaining something in mid sentence (mid-word, even?) and just sat down on the floor next to my drum and waited. Silence happened quite soon, and then I finished the explanation in a whisper. The rest of the lesson went much better - I won't say the children were quiet - samba really isn't that kind of an activity - but I had their attention.