Evolution and the moment of silence for a broken glass

Broken Sky by makemesomeart

You know how when someone drops and breaks a glass in a noisy restaurant, there is that brief lull in conversation? Even though we know what it is, we've heard that many times before, still, the group gets quiet for a moment.

I like to think this goes back to the days when a strange noise could be a predator lurking in a bush, and the group becoming silent so they could listen and figure out what is going on could be the difference between life and death.