How to train perception?

Lately I have realized how awfully unaware of my surrounding I am in terms of visual and audio reception. I have never been able to generally locate the source of a sound by just listening to it (I could not know it was the person sitting in front of me who was playing music through his phone's speaker the whole time on the bus.) I have to walk back and forth to know if the audio source is close or far from me. In terms of eyesight, I find it hard to notice small to normal details like a pen in the pocket or the color of the tie or whether or not a person is wearing a watch.

Is there a way for me to train myself to better more perceptive? I just find it interesting and quite something I can use later on .