The Secret Struggle in Crawford's Room

This past Wednesday, April 11th, there was a very annoying and painful high pitched noise coming into the room occupied by Calculus teacher Mr. Crawford. This noise was not heard while walking through the hall nor could Crawford himself hear the noise. This noise do to its annoyingly high pitch, had to have been of a higher frequency than less annoying pitches. Also, as humans age, we can begin to lose the keenness of our hearing of high frequency sounds. This explains the confused look on Mr. Crawford's face when the entire class complained about the seemingly nonexistent noise.