Let's look at some very unusual sounds that come from nature -
Taos Hum: A persistent low-frequency hum heard only by some people in the Taos, New Mexico area.' A source has not been found.
Ringing Rocks: Upper Black Eddy in Bucks County, PA has a huge wash filled with rocks that when knocked with a hammer, making ringing sounds.
Ohio's strange sounds: Lots of other states have reported this sound too.
In an intriguing episode on National Geographic, investigators tried to find out why Eastern State Penn was so haunted and came to find that when it rained and because of the construction and shape of the building, it created infrasound -- sound below the range of human hearing, but that makes you experience everything from seeing shadow people to feeling watched and uncomfortable. Just look at what happens when a teen in a car with huge bass speaker and music playing loudly does to your body when they pull up next to you at a stoplight. Your chest and body thump. We could be feeling sensations to things we can't even perceive with our ears. Some believe the reason dogs bark before an earthquake is because they can perceived the infrasound that occurs. This is an interesting new field of research.
Some even have supposed that Bigfoot is able to create infrasound, thereby making us so uncomfortable, we rush away. Cool, huh?