The cause of this strange phenomenon remains unknown.
According to one man who lives in the suburbs of Pittsburgh, somewhere high in the sky is a source of strange sound, prevent live peacefully. The sound is similar to metal or bassy roar “Trebinje”. The man was able to record the anomaly on the video, the material is attached below.
A strange roar is not terminated, in connection with which creates a certain discomfort: interfere with sleep at night. The hero of the story already went to the officials but to no avail. Near no factories or airports, so the sounds supposedly nowhere to be. A resident of Pennsylvania had already begun to think about moving, because the sound slowly drives you crazy.
According to the American, in the sky the aliens are conducting some kind of activity. It is noteworthy that this occured in other parts of the world. At the moment, the man communicates with ufologists to investigate.
It is important to note that previous cases of “trubine” failed to study: the audio source is either well hidden, or is too high. Not the fact that this investigation succeeds.