Researchers use 3D sound mapping to show aerodynamic forces during flight explain eponymous sound
Hummingbirds might be instantly recognisable from their eponymous sound, but the cause of the characteristic has long been a mystery.
Now researchers say they have cracked the conundrum, finally taking the “hmm?” out of hummingbirds.
David Lentink, the assistant professor of mechanical engineering at Stanford University and a co-author of the research, says that while the hum was known to be linked to the movement of the wings, it was previously unclear what exactly was behind the sound. Pressure changes generated by the flapping, vortices in the air flow, and whistling sounds from the feathers themselves were all among the possibilities.
Now it seems the answer predominately lies in the aerodynamic forces, and hence pressure changes, produced as the wings move.