I’m a little reluctant to release this, as the police may use it on the occupy protestors. This is one annoying sound!
It was pretty hard to hear what the circuit sounded like in the video, so I modified it to have a line level output and recorded it on my computer. At first I was baffled, as the volume kept going up and down, and there were weird compression artifacts until I figured out the sound card in my computer was doing all sorts of noise reduction and signal processing on the microphone input! I turned it off and here’s the raw sound: