Sit in a quiet room, take a clock and keep it at a proper distance. The distance of the clock should be such that you can hear its ticking sound comfortably. Now close your eyes and listen to the ticking of the clock carefully. When the ticking sound starts to be heard very clearly near you, then increase the distance of the clock from where you are hearing it unclearly. After a few days, the ticking of the clock will start to be heard clearly. When we concentrate on listening to the ticking of the clock repeatedly by using our