YouTube user 'ShadowBandit91' shared footage of 'trumpeting sounds' he heard in the North Carolina sky on July 15, 2019:

So, I was coming into work like normal. I got into work at 3:30am ... no construction, no loud vehicles, nothing on the two major highways. It is quiet when I come into work. I've never heard the sound before or since I've been coming into this building for 11 years (more less.)

In my 28 years of living, I've never heard a sound like this at all. It sounds like mating calls for whales or a really good trumpet player that can throw sound from hell-a-far. It was so loud when I walked into the building, I could hear it before I could even open the warehouse doors and for those of you have not seen videos of my warehouse, you can tell what doors I'm talking about. I could hear that clearly so when I stepped outside this is what I heard:

On July 2, 2019, YouTube user 'iamtheicelord' uploaded footage of strange "unsettling" sounds he heard in the skies of Merrillville, Indiana:

Earlier this summer right in the middle of June 2019 my friend and I stepped outside to grab some air and started hearing these strange low rumbling horn like sounds coming from the distance. We got a couple of them I'm recording. Let us know what you think they were.

A mystery over a loud noise which woke people up across North Lincolnshire and the surrounding area remains unsolved - although an earthquake has been ruled out.

The noise was heard around 10.30pm on Thursday last week in places including Epworth, Crowle and Gainsborough.

Some people who heard the noise initially wondered if it had been an explosion or an earthquake.

Some attributed it to a sonic boom - the noise an aircraft makes when it breaks the sound barrier - but the RAF confirmed none of its aircraft would have made the sound in the area at the time it was heard.

It happened on the same day that southern California was hit by a 6.4 magnitude earthquake, the biggest in 20 years, leading some people to believe there could be a connection.

On May 13, 2019, YouTube user 'D4RK-AURA' uploaded video footage of strange noises he heard in Tennessee:

Some residents living in Cleveland's Slavic Village neighborhood are reporting and recording unexplained booms and flashes of light in the nighttime sky at all hours of the evening.

Some of the light flashes and explosions have been recorded by home outdoor security cameras and are being posted on YouTube. Some are posting comments on Facebook.

In recent weeks, the phenomenon has left residents guessing and speculating.

Community activist Edward McDonald said the sonic booms are shaking both homes and the nerves of homeowners in the area of Fleet Avenue.

"What I've heard is like a loud bang, like a boom," McDonald said. "It shakes houses, it rattles windows. It hasn't caused any destruction yet, or it hasn't caused any property damage, but it's definitely noticeable."

On April 20, 2019, YouTuber 'Dumitru Daniela' posted video footage of strange noises she heard in the skies of Tulcea, Romania on March 20, 2019:

Hi guys! I really need your point of view about this strange noise. There wasn't any sign of plane or helicopter, no wind, no explosion, no asteroid.

She comments that the nearest airport was 16 km from her city and hadn't been operating since 2014. Nobody heard anything from the area of the city's stone quarry either.

The sound was bizarre enough that she notes the effects she saw and felt then:

The strange thing about the noise is that he [it] was going straight ahead and coming back but not rise up... and more than that, the sound was so powerful like you could feel the vibration of it, like when you are staying next to a speaker.

On May 1, 2019, You Tuber 'Abhigyan Rai' shared video of strange sounds he heard in the sky of Kurseong, West Bengal:

On April 21, 2019, YouTuber user 'B. Attila' published two videos of strange sounds he heard in Kazincbarcika, Hungary. He reports that the noise 'was very loud' and that 'there are no factories, railway networks and other facilities nearby that could produce [the] loud noise.'

On April 7, 2019, YouTube user 'Zahra Khoshonesh' uploaded video of strange sounds she heard in the skies of Tehran, Iran:

On April 10, 2019, YouTuber user 'Peter The Pleater' recorded two strange sound events he heard at his home in Shirehampton, Bristol, UK:

First heard 10pm, last heard 3am on night of 10th/11th April 2019. Repetitive trumpet/metal grinding sound that was at times very loud.

Woke up my children, and later me. Very strange. We live in Shirehampton, near Bristol Port so this could conceivably be big ships moored in the harbour making groaning noises, but otherwise I am not sure what to think! Was genuinely spooked by it. Sounds a lot like the 2018 Gothenburg video.

The roaring background noise is the M5 motorway which is somewhat dampening the strange sound. It was much clearer/louder in real life.