No, these aren’t sounds of random animals or top secret planes, but rather real clips that can’t be explained. Sure, some of them are theorized to be icebergs, like “The Bloop” and “The Slow Down Sound”, but all of it is just speculation. Continue reading to hear them all.

5. The Bloop

Bloop is the name given to an ultra-low frequency and extremely powerful underwater sound detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. According to the NOAA description, it “rises rapidly in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over 5,000 km.”

4. Mistpouffers

Mistpouffers are unexplained reports that sound like a cannon or a sonic boom. They have been heard in many waterfront communities around the world such as the banks of the river Ganges in India, the East Coast and inland Finger Lakes of the United States, as well as areas of the North Sea, Japan and Italy; and sometimes away from water.

3. Slow Down Sound

This sound was recorded May 19, 1997 on the Equatorial Pacific Ocean autonomous hydrophone array. The sound slowly descends in frequency over about 7 minutes and was of sufficient amplitude to be heard on three sensors at 95W, and 8S, 0, and 8N, at a range of nearly 2,000 km. This type of signal has not been heard before or since.

2. Saturn’s Radio Signal

In May 2005, Cassini began a series of occultation experiments, to measure the size-distribution of particles in Saturn’s rings, and measure the atmosphere of Saturn itself. For over 4 months, Cassini completed orbits designed for this purpose. During these experiments, Cassini flew behind the ring plane of Saturn, as seen from Earth, and transmitted radio waves through the particles. The radio signals were received on Earth, where the frequency, phase, and power of the signal was analyzed to help determine the structure of the rings.

1. Trumpets

There have been some mysterious, trumpet-like horn sounds, heard booming from the sky all around the world. These bizarre noises were heard recently from Europe to Canada – in Germany, noises coming from the sky were recorded on a video camera and uploaded to YouTube, with car alarms clearly heard going off in the background.

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