system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why, when our ears pop, does it seem like we suddenly have HD hearing?
gpt
Only because your hearing was very gradually being worsened until the pop.  So gradual you hardly noticed.
 
The pop is when air pressure on both sides of your eardrum is equalized after gradually being unequal, allowing your eardrum to function correctly again.  
  
I.e. The pop returned your hearing to normal very suddenly.