Strange sounds (stock)
YouTuber 'Christine Diamond' uploaded video of 'crazy sounds' she heard in the skies of Delaware County, Pennsylvania on December 2, 2018.

'Christine' notes:
People around here keep insisting it was a firework show in the next town. However the sound was very loud and deep it did not sound like a firework show.
Two commenters on the video reported they heard the same sounds. One was in New Jersey and the other in Verona, Pittsburgh who said they heard the noise twice in the last two weeks.