MP3 player. How does it work? Why would it respond to gold rather than something else? Please. I am serious, not making fun. I have at least one place I would like to try it out. This place is near or under power lines. How would that affect it? Also! How about digital cameras. I have a couple of kodaks. I also an android phone with a nice camera. Any info you gave would be helpful. I have also heard of function generators used for treasure hunting.