Source: PLANETA UFO and Clarin.com
https://www.clarin.com/sociedad/misteriosos-ruidos-inquietan-habitantes-cipolletti-neuquen_0_r1t4E1qf-.html
Date: 06.12.2017
Argentina: Bizarre Sounds in the Sky Over Cipolletti and Neuquén
* Loud Howling Sounds Heard in the Early Morning Hours *
Residents of Cipolletti and Neuquén were startled awake this morning when a loud, inexplicable sound could be heard over both cities. The sound appeared to emerge from an elephant's trunk, but clearly these animals native to Africa and India are not readily found in Alto Valle. No one dared offer reasonable explanations about the event. The "trumpet" is a mystery in the locality, one which shall be told to children in later years.
According to media and residents of the province using social media, "abysmal screams or howls that wound up dominating the night" could be heard around 2 o'clock int morning. The testimony of frightened witnesses soon became known.
Someone on Twitter said it was a garbage truck making its rounds of Cipolletti's various neighborhoods. According to this story, the truck must have been experiencing motor difficulties. Another possibility is that its brakes were not properly lubricated and that the "alien-flavored trumpet" made itself heard whenever it stopped.
The problem with this theory is that there are residents of Neuquén Capital and other cities of Alto Valle who also described hearing a similar phenomenon. Videos taken with cellphones are proof that this is not an urban legend.
Last July, area residents were frightened by explosions heard past midday outside General Roca, a city near Allen and Cipolletti. A local mining concern said that the sounds "had no relation to their quarry operations" so the mystery was never solved.
An astronomer from the Neuquén Observatory said days later that the explosions had been caused by a meteorite measuring 12 meters in diameter. This theory did not satisfy those who were disturbed by the noise.
[Translation (c) 2017 S. Corrales, IHU with thanks to Guillermo Gimenez, Planeta UFO]
{NOTE: Clarin.com includes an eyewitness video taken by a citizen willing to brave the cold night to capture the strange howls on his cellphone. It can be seen (and heard) at "Extraños sonidos en Cipolletti" https://vodgc.com/index.php/extwidget/preview/partner_id/102/uiconf_id/23448755/entry_id/0_d57l8rbn/embed/dynamic and the howls can be heard faintly at 0:11, 0:26, 0:42, 0:48, 0:58 and 1:13]