The pop of a pop-gun is one of the all-time great sounds. All you need is a tube, a plunger, and a tapered cork. The cork should fit snugly in the end of the tube, and the plunger needs a plug at the end fitted to the interior of the tube. When you insert the plunger and slide it rapidly toward the corked end, air pressure causes the cork to pop out. Pop guns can be large or small. They produce varying pitches, but you can’t control the pitch with any accuracy, because it depends on where along the tube the plunger’s end-stopper happens to be when the cork pops out.
In the sound clip, pop gun pops are mingled with the slightly different tone of suction pops.