hear a pin drop, one/you could

hear a pin drop, one/you could

Complete silence. This hyperbole dates from the early nineteenth century. An early appearance in print is in Susan Ferrier’s The Inheritance (1824): “You might have heard a pin drop in the house while that was going on.” Although pins are a far less common household item than they once were, the expression survives.
See also: could, hear, one, pin