And as you may know, the Martian heat ray sound effect was a truck starter motor. (The visual was created with a grinding wheel photographed in a darkened studio.)
I figured the visual was a grinding wheel or maybe some kind of welder, but I had no idea about the audio portion. But recalling the "beat", yeah, that does make sense. What about the "levitation" audio, the sound later used for the phasers? I'm personally reminded of cicadas or locusts, but what was really used?