The blue whale, which is also the largest known animal on earth, produces the loudest sound. These giant marine mammals create a variety of vocalizations, including low-frequency humming and loud whistle-like sounds that can travel through hundreds of miles of water, possibly even through the entire ocean.
This blue whale sound measures in at 188 decibels, which is louder than extremely loud things such as jet engines and the peaks of live music. Though the blue whale's sound is in proportion to its massive size, not all loud animals are proportionately huge. The next loudest animal on earth is the howler monkey.