So:
Meteor Shower Audio of the Day: A US Air Force Space Surveillance radar in Lake Kickapoo, TX captured audio from the Perseid meteor shower over the weekend.
The “pings” you hear, reminiscent of sound effects from a retro video game, are caused by meteors hitting the Earth’s atmosphere. At the peak of the Perseids, observers reported 20 meteors per hour, each traveling at around 133,000 mph.
(Direktlink, via TDW Geek)