This is a trick question of sorts with two animals sharing the title depending on your perspective. The sperm whale has been recorded reaching 230 decibels, the loudest recorded sound in the animal kingdom. However, they can hold that level for less than one second. In fact, they can only maintain the sound for 100 microseconds. Considering that a microsecond equals 1 millionth of a second, the 230-decibel sound emitted by a sperm whale happens in such a fraction of a second that the human ear would not likely hear the noise. However, any noise above 120 db is considered painful to the human ear so the 230-db sound would most likely happen so quickly that a person wouldn’t hear it, but would feel it – and it would hurt.
The blue whale is widely considered to be the world’s loudest animal because the 188-db threshold it routinely reaches can last up to 30 seconds. The call of the blue whale is so loud that it can be heard more than 1,000 miles away and is believed to be heard across any ocean in the world.
A third contender is worthy of mention to the title of loudest animal, and the pistol shrimp’s unusual use of sound is so unique that it could easy win the argument for most creative use of sound. The crustacean has a special claw that is able to snap shut so quickly that it creates a shockwave that stuns prey which the shrimp can dismember and eat. Like the call of the sperm whale, the sound created by pistol shrimp (also called the snapping shrimp) lasts for just a millisecond, but the short burst can reach 200 db. Resembling the sound of popcorn popping or a person snapping their fingers, the predatory sound of the pistol shrimp can easily be heard by anyone swimming, snorkeling or scuba diving in the shallow, warm waters the crustacean inhabits.