1.   After he finished telling the story you could have heard a pin drop.

2.   The auditorium was quiet enough to hear a pin drop.

3.   Well you could have heard a pin drop.

4.   You could have heard a pin drop if anyone in the room had dropped one.

5.   You could have heard a pin drop in there.

6.   Suddenly you could have heard a pin drop, which is enough to make anyone feel self-conscious.

7.   The other players carried on getting changed and opening lockers and stuff, but you could hear a pin drop.

8.   You could have heard a pin drop.

9.   And when he died last week, you could hear a pin drop.