Florida witnesses alerted to hovering UFO by loud humming sound...Unusual Sounds in the Air and Water of UFO and UAP...Air Force Witness: UFO Moved Slowly With Unpleasant Hum!...What Does a UFO Sound Like? Actual Recordings of UAP sounds

"The reporting witness heard the humming sound for five to eight seconds and first thought it might be someone’s garage door opening.

“But it was unusual, unlike anything we ever heard before,” the witness stated. “It was so loud it caused alarm. So we immediately went outside. Several neighbors went outside to express concern and alarm. The dogs in the neighborhood were barking and then they got very quiet.”

The witness looked north and saw an object hovering"
https://beforeitsnews.com/paranormal/2014/09/florida-witnesses-alerted-to-hovering-ufo-by-loud-humming-sound-2475830.html

"Unusual sounds in the air and water that are associated with UFO and UAP sightings are often described as a low hum, buzzing, or droning sound that is heard in the vicinity of a UFO or UAP."
https://unidentifiedphenomena.com/topics/unusual-sounds-in-the-air-and-water-of-ufo-and-uap/

Air Force Witness: UFO Moved Slowly With Unpleasant Hum! #shorts

What Does a UFO Sound Like? Actual Recordings of UAP sounds