There is a 'why' and a 'how' to listening to God. If we know why to listen, but don't know how, then we won't be able to listen at all. If we know how, but don't know why, then we won't be able to make use of that knowledge. It's best to both understand the process and make use of it.
Why listen to God? Contrary to popular belief, God isn't pointing fingers and commanding "Do this! Don't do that!". God is more like: "Isn't that flower beautiful over there?" or "You know, if you bang your head in the wall, it's gonna hurt." He likes to tell jokes too; some are quite funny, but sometimes he misses the context. (That's God for you.)
Listening to God is an internal process. We are part of God, and God is our 'true self' in the deepest sense. Thus, when we listen to God, we listen to our true selves. Is it possible not to listen to ourselves? Sure it is - then we end up confused and conflicted. (If you listen to God, you find/create yourself, if you don't, you lose yourself.)
How to listen to God? An important part is breaking the habit. Not only our behavior, but also our thoughts and emotions have habits. Many of these habits are detrimental and they are like 'static interference' over our lives. Due to such habits we do things without really thinking or feeling them through. To listen to God we have to break these habits and awaken from the slumber.
When we remove a set of limitations from ourselves, we open up to new experiences and we're able to see the world more fully. God speaks through the experiences of our lives, and we speak to God by choosing how we wish these experiences to influence us. The communication with God is there within our being - we can choose to 'tune in' and listen to God consciously.