Inspired by this two beautiful icons

http://dribbble.com/shots/794473-Video
http://dribbble.com/shots/805972-Yes-No-3

I decided as an exercise to make my own. When I finished, the icon reminded me of a game that I played (Silent hill) and on a radio in the game that helped me to notice the creatures so ...
In honor of silent hill here is the frequency generator :) 
Hope you like it ...