When it comes to making noise in the natural world, the blue whale (Balaenoptera musculus) takes the podium for being the loudest animal. For not only is it the largest animal on the planet, it’s also the most vocal.
This marine mammal can emit rumbling calls, known as ‘songs’, recorded at over 180 decibels (dB) – loud enough to cause permanent damage to human eardrums.
Its cacophony comes with a purpose. Blue whales are baleen whales, meaning they have bristly baleen plates instead of teeth, which are used to filter small prey from sea water.
They are often solitary, swimming alone except when mating or migrating – so they need a booming call to communicate with fellow whales in the expansive submarine world to find mates and develop social bonds. In fact, a blue whale’s song, generated by its super-large larynx and vocal chords, can be heard thousands of kilometres away.
Toothed whales, such as the sperm whale, also make a racket under the waves. Using echolocation, a sperm whale can find its prey (often a jumbo squid) at depths of up to 1,800 metres. Its high-pitched clicks can reach 230dB, technically louder than a blue whale’s song, but last for a mere fraction of the time. When considering combined loudness and duration, the blue whale comes up trumps.
Back on land, various creatures vie for the title of loudest land animal. The echolocation signals of the greater bulldog bat can hit a piercing 140dB, as can the screams of a howler monkey.
The loudest bird in the world is responsible for an ear-splitting sound that's far from the tuneful birdsong you would expect.
A person shouting is around 85dB, while a baby crying can exceed 100dB. So, next time you can’t ‘hear yourself think’, be grateful for the limits of the human voice box.