Shush

I stared at the board while the teacher was writing, the whole class was quiet, all focused on writing down what's on the board. I heard a yawn from my left and accidentally copied him, I covered my mouth as to not make any sound. I looked towards the board and the teacher was still writing, so I glanced around a bit. Some of my classmates were not writing, some even fell asleep. "Shush class," the teacher said, I looked at her and then to my classmates, I didn't hear anything. I ignored it and continued catching up with what's being written on the board, the room as silent as ever.

The room suddenly got colder, I looked at the thermostat but the temperature remained constant. Out of the blue, I heard the teacher say "Class quiet down, finish your work!". Once again shocked, I turned my head and looked at my classmates who were as confused as me. We all just kept quiet for the rest of the time while worriedly looking around, wondering what it is that our teacher heard.