11 of the Loudest Animals on Earth

Blue Whale

The blue whale, the largest animal ever known to exist on Earth, has an impressive call to go with its massive size. The call of a blue whale reaches 188 decibels—louder than a roaring jet engine's ear-piercing 140 decibels. They make pulses, groans, and moans that can be heard up to 1,000 miles (1,600 kilometers) away. Researchers have found that blue whales have been lowering the frequency of their calls over the last several years. Climate change, warmer waters, and ocean noise could be to blame.

Listen to the blue whale on the NOAA Pacific Marine Environmental Laboratory.

Sperm Whale

Although blue whales are considered by most to be the loudest animals, there are many ways to measure loudness. At pure decibels, the sperm whale is louder than the blue whale because its clicks have been recorded at 230 decibels. Sperm whales communicate at a lower frequency and a lower intensity than blue whales, and their clicks last for very short bursts. They’re often out of the human-hearing threshold. Research has found that sperm whales seem to speak in distinct dialects. Apparently they also make a trumpet sound at the beginning of a dive.

Listen to the sperm whale on Ocean Conservation Research.

Snapping Shrimp

Primarily found in coral reefs and oyster reefs, snapping shrimp (also known as pistol shrimp) stun their prey by closing the larger of their two claws shut at a speed of about 62 mph (100 kph). That action forms a giant air bubble that makes a loud snapping sound when popped. As loud as 200 decibels, the sound is enough to stun or even kill the shrimp’s prey. Humans with their heads submerged underwater can hear them as a popcorn or crackling sound.

Listen to the snapping shrimp on Ocean Conservation Research.

Howler Monkey

Named for their unmistakable cries, howler monkeys are the largest of all New World monkeys, found throughout Central and South America. When several howlers start yelling at dusk or dawn, they often can be heard as far as three miles away, telling other monkeys to stay away. Male monkeys have large throats and shell-shaped vocal chambers that give them the ideal anatomy for sound. Their howls have been recorded at 140 decibels.

Listen to the howler monkey on the University of Michigan's Animal Diversity Web.

Bulldog Bat

When bats navigate and forage for food, they use high-pitched calls and echoes. This echolocation helps them, but only within a short distance. Researchers figured that bats with higher-frequency calls would cover greater distances with their louder cries. In a 2008 study published in PLOS One, researchers found that the lesser bulldog bat (Noctilio albiventris) and greater bulldog bat (Noctilio leporinus) reached 137 decibels and an estimated 140 decibels. Bats also make low-pitched calls to let other bats know they're around to avoid collisions when hunting.

Listen to bats and watch how they hunt on Discovery.

Kakapo

The world’s largest parrot is also the loudest bird. The critically endangered bird, which is nocturnal and flightless, has a varied vocabulary that includes squawking and braying sounds. The male kakapo emits a sonic boom-like noise during breeding season. Then, after 20 to 30 loud booms, it makes a high-pitched metallic “ching” call, also described as a wheeze. The loud booms can reach 132 decibels. This boom-ching pattern can go on continuously for up to eight hours every night for two to three months. The kakapo will give loud territorial calls as well, screaming in response when scientists play another bird's boom call through an amplifier.

Listen to the kakapo on the Cornell Lab of Ornithology's Macaulay Library.

Lion

The king of the jungle can be pretty intimidating when he roars. In a 2011 study in PLOS One, researchers found that these big cats have flat, square focal folds. (By comparison, humans and many other animals have triangular folds, or vocal cords.) The folds are very elastic and fatty, allowing them strength and flexibility as they vibrate. A lion can roar as loud as 114 decibels, and typically lasts as long as 90 seconds. That's about 25 times louder than a gas-powered lawn mower.

Listen to the lion on the British Library's sound collection.

Bushcricket

A recently rediscovered species of bushcricket has a calling song as loud as a chainsaw that males use to attract females. Researchers found that the male katydid (bushcricket Arachnoscelis arachnoides) sings at about 74 kHz, using “stridulation,” where one wing acts as a scraper rubbing against a row of teeth-like grooves on another wing. The movement results in high sound levels of about 110 decibels.

Listen to the bushcricket via Orthoptera Species File Online.

Oilbird

This nocturnal bird, known as the guácharo in its native South America, uses echolocation to navigate in its dark cave home. In studies, researchers measured their clicks as high as 100 decibels. Unlike the calls of bats, the sounds of oilbirds are within the range of human hearing. The sound is nearly deafening when large groups of the birds gather to roost.

AskNature explains how it works: "The bird contracts its respiratory system in a way that allows it to emit quick bursts of audible clicks. The sound waves bounce off objects, returning to the bird’s ears in a way that allows it to determine the objects' sizes and locations and so avoid smashing into them."

Listen to the oilbird on the Cornell Lab of Ornithology's Macaulay Library.

Water Boatman

Relative to their size, water boatmen are the loudest animal on Earth. They’re also the only ones that make their deafening noises using their sex organs. The calling song, meant to attract a mate, is produced by the male water boatman (Micronecta scholtzi) rubbing his genitals across a ridge on its abdominal segment, earning the nickname of the "singing penis." The result is a 99 decibel sound that can be heard by humans on the other side of a pond. (The Center for Biological Diversity said 78.9 decibels, which is comparable to a passing freight train—still impressively loud.)

Listen to the water boatman on the British Library's sound collection.

Common Coqui Frog

Coquis are small tree frogs that are named after the male’s loud “ko-KEE” call. Males often respond to the first part of the call as a warning to stay away, while females are attracted to the second. The frogs are a problem in Hawaii, where they have no natural enemies and have reached populations over 10,000 per acre in some areas. Their calls are as loud as 80 to 90 decibels, compared to a lawnmower, and have caused restless nights for residents and tourists.

There's some concern that environmental change is affecting the length and pitch of the calls, and making it harder for females to pick up on mating signals. From Smithsonian Magazine: "Because they are so sensitive to temperature, frogs and other ectotherms may face higher risks with climate change in general, and their communication systems would be more indirectly at risk."

Listen to the coqui on Hawaiian Ecosystems at Risk.