Prolonged silence
Consider these, separately:
A fork tapping a wine glass
The words, “Let us pray.”
The phrase, “May I have your attention please?”
A request for volunteers
The first three situations prompt brief silence, and then someone speaks.
It’s that fourth one that presents the most awkward and prolonged silence.
You’re at a meeting. Heads will nod. All will agree: Yes. This is something we need to do. It’s important.
“And who will volunteer to do it?”
<silence>
Many times, we don’t need more head-nodding.
Many times, we need more people to raise a hand and to step forward.