It has been shown my various posts Ive made, that
There is a valid geologic/scientific explanation for the alleged sounds.
Despite stories, there are cases where the alleged videos were made, where no-one actually reported any sounds to anyone
A sharp eared web guy studied and isolated the sounds and compared the wave forms and sounds, to the same sounds in a movie, (about sounds in the skies funny enough), and has suggested without doubt, the sounds are the same. I happen to agree with the samples he chose
A video has been posted that shows a snow plough and the sounds it makes, along with examples saying road scrapers also make sustained long sounds...at night...when the roads are not busy
And...a pro UFO site has claimed they are the hoaxed works of religious cults
In fact there have been a few more examples of other possible sources creating sounds.
Also to further show that you do not know what you are talking about. That is a Motorgrader, not a snow plow. That is what we call "A Blade" being used to clear snow. A Snow plow is more similar to a front end loader with an upside down V shaped blade on it. Got it?