Whenever I am not hearing from God, I ask myself, "Who moved?" Invariably, I am the one who has not maintained the relationship in the manner I should.
Prayer and reading the Bible are essential. I do notice sometimes I go for a while, faithfully reading my Bible, and God is showing me nothing. I first, very humanly wonder if there is nothing left to learn! Ooops! Never!
Then, I repent of my sin of not keep the lines open to God. And he usually just pours out his love, his kindness and gives me wisdom when I read the Bible.
I have heard from God audibly a few times. When I was saved, when God called me to seminary, when he called me to start attending a certain church. They did come to pass. I especially needed to hear the voice of God in order to be saved. That was because I had such a hard heart. But those were voices inside my head. And it doesn't happen like that, very often. And no mental illness here!
When I turned away from God for 2 years, because of the pain and sickness of RA, I knew God was always there, right behind me. He told me to read 5 psalms a day. I finally did for 2 years, and it healed my heart, and suddenly, I was on good meds and got my life back.
There are certain Catholic saints who call not hearing from God, "The Dark Night of the Soul." I even got the book, but never managed to get through it, because the language was so archaic. Something you might want to look into, although I cannot vouch for the source. Still, the phrase has a nice ring to it, n'est-ce pas?