Over the last few days, an unexplained strange sounds in the sky is annoying residents of several districts in Cluj, Romania.
Here a recording of these weird noises from the sky.
A Youtuber finds that ‘the sound is exactly that of an airplane propeller, which is in the startup phase / ground test engines. Such noise is frequently heard from the airport. The atmospheric conditions were probably favorable to transport the sound waves over long distances.
Good or bad explanation? You have the last word on this new mystery sound.