Hearing is the only human sense that remains fully active while you are deeply asleep, constantly monitoring your environment for potential threats so you don't get eaten by a…

A closer look

Hearing is the only human sense that remains fully active while you are deeply asleep, constantly monitoring your environment for potential threats so you don't get eaten by a predator; your brain simply blocks most of the auditory processing so you can stay unconscious, but it actively filters for important sounds like your name or crying babies, which perfectly explains why your deeply ingrained evolutionary survival instincts can be instantly bypassed by the persistent, ungodly shrieking of an iPhone alarm clock set to the radar tone at six in the morning