Sperm whales are loud. One particular sound they make is considered one of the loudest mammal-made communication sounds on Earth. Why they make this particular sound isn’t fully understood, but one theory suggests the whales are basically peacocking, being loud and obnoxious as a way to stand out and attract a mate. Or maybe it’s to warn other males that there’s a big bad whale in town. Who knows. But it is loud as heck.According to a new study published in the Annals of the New York Academy of Sciences, researchers recorded male sperm whales in waters off the Seychelles, Sri Lanka, Norway, and Scotland, paying extra attention the mysterious “slow clicks” they make, the cacophonous calls they make every 5 to 10 seconds.Saying they’re loud is an understatement. They top out at around 200 underwater decibels and, as such, can travel as far as 70 kilometers when the sea conditions are ideal. Male sperm whales pull this off thanks to a huge nasal cavity that can weigh more than five tons. The bigger the whale, the lower the pitch, leading researchers to suspect these clicks were more about the whale showing off its size. Think of it like a guy revving his sports car engine to get attention at a red light.Sperm Whales Are Basically Revving Their Engines Underwater, Study SuggestsThe actual reason they put this message out there is not completely understood. The clicks could attract females, but they can also be a warning to nearby males, or maybe it’s a bit of both. It’s a mystery, along with how the whales managed to maintain the sound’s steady rhythm. One theory suggests that they use the echoes bouncing off of the seafloor as a kind of all-natural metronome that keeps them on beat.While the researchers do call it a communication sound, they stop short of grouping it into the broader whale language. There’s no evidence yet that the whales are using this sound to chit-chat about the weather or whatever. For now, all they know is that sperm whales can get loud and don’t really care if you’re bothered by the ruckus.The post Sperm Whales Make One of the Loudest Sounds of Any Mammal, and Scientists Still Don’t Fully Know Why appeared first on VICE.