If you destroy your sense of hearing, or that of someone else, that does not mean that the world stops making sounds. You, or that other person, simply have become deaf.
Likewise if you destroy your own or someone else's ability to hear God (as he actually speaks), that doesn't mean God has gone away. It simply means that you have committed spiritual suicide or murder. God is still there even if you destroy your own or someone else's organs of hearing.
This is why God insists that children be raised "in the faith." It is not an "adult option." Would you pour lye in your children's ears figuring they shouldn't hear anything until they are adults and can have "hearing aids of their own choosing" installed.
Wise up. Hell's packed already but has infinite capacity, expanding to need.