Netwrck 
Narrator
Choose your voice
Audio Volume
Image Generator
Bloop
Bloop is the most likely to come from some sort of animal, because its signature is a rapid variation in frequency similar to that of sounds known to be made by marine beasts. There's one crucial difference, however: in 1997 Bloop was detected by sensors up to 4,800 km (3,000 mi) apart. That means it must be far louder than any whale noise, or any other animal noise for that matter.