User Defined Sweep

I had an idea today. Earlier, we had problems with an overview of the map, which I will call a gist. We didn't know how to give an overview of the map, but we knew we needed to have one. I thought that maybe we could have the user define the sweep. For example: the user presses a button and sweeps his finger across an area he wants to know more about. The computer will then play a sound for every group of pixels he passes through. For this design, we will need to experiment to get the right settings. we will need to experiment with how big the groups of pixels will be, what shape those groups would be (square, hexagon, triangles, etc.), how fast to do the sweep (same speed as user sweep, or set speed), and what information would be in the sweep. If you have any other ideas, please feel free to post them.