Posted by R. Berg on December 11, 2001
In Reply to: So quiet you could hear a pin drop posted by Nikki on December 09, 2001
: Does anybody have any idea where this saying originated or what it applies to?
It applies to any instance of silence or near-silence. I haven't found an origin for it specifically. The Oxford English Dictionary has a quotation from 1870, "As the phrase is, 'you might have heard a pin fall'" (Miss Mulock, "Fair France").