Imagine not reading for 10 years because of bad eyesight, eye glasses do not make it so your brain can read, but instead makes it easier for your brain to see the symbols. your brain still needs to decode and comprehend them.
Our hearing system is far more complicated. You can look in the direction you want to see....but you hear all around you, even through walls.
You cannot stop hearing, even in your sleep. It is far more crucial to our environmental awareness than more people realize.