Have you ever stop and just listen? You could do it at the trainstation, your home, your workplace, or even at the toilet.   I mean really listen to everything. You might be surprised by the number of things you heard.

Today at the station, I heard people talk to each other, the footstep, the sound of the train itself, and the driver's annoucement.  It's a lot of fun to distinguish all the noises that your ears pick up and then to concentrate on the important one -- like people's conversation.

On the other hand, if you wear headphones, you will get the feeling that you're in some kind of movies, and the music is playing in the background. You will begin to use your eyes more than your ears.  And you will notice something differently.

Try it. It's fun and educational.