On rare occasion, Santa Cruz residents have noticed an object in the night sky flying south at low altitude. The general consensus is that it must be a drone because a conventional aircraft would be much louder and obnoxious. Could it be a Joby test flight? We may never know. But in this video, engineers at Joby flew a series of aircraft over an array of calibrated microphones, demonstrating the low noise profile of the evolutionary Joby aircraft. This is one of the reasons why Joby Aviation is turning the heads of the conventional aircraft industry.