Look at the Bible. Look at all the different ways God spoke to people. Moses (burning bush), Gideon (dew and fleece), Paul (bright light and a voice), and so on. But nowadays, many people don't often have these physically tangible forms of communication with God, let alone hear an audible voice. But look back at the first sentence in this paragraph. Look at the Bible. We have the whole complete Word of God. It is one of the major ways that God speaks to us. Remember that when you rely on the Word of God, it will never lead you astray.
We should spend time listening to God's voice by reading the Bible, by spending time in prayer, or just in quiet thought about Him and His promises, or even in worship. The more time we spend with Him, the more easily we recognize His voice and when He is speaking to us.