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  • Richard Conniff writes about behavior, in humans and other animals, on two, four, six, and eight legs, plus the occasional slither.

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Loud Neighbors

Posted by Richard Conniff on March 2, 2011

Howler monkey with a song in its heart

The first time I visited a rain forest, in Panama in about 1981, I woke up to a horrific roaring.  My first thought was, “Oh, my God, Reagan’s done it.  He’s fired off the cruise missiles.”

Turned out it was just the howler monkeys saying “I’m awake now and if you come any closer I will throw shit at your head.”

With that memory in mind, this item from The Mail caught my eye.  It’s about a few of our noisier neighbors:

The male blue whale’s song reaches an astonishing 188 decibels, while a jet engine reaches 140. A staggering difference when you think that the decibel system means that a rise of ten decibels corresponds roughly to a doubling of volume.

That means a whale’s song is almost five times louder than a jet.

Blue whale calls can be heard up to 1,000 miles away — which is useful because they can be miles apart from one another, and only occasionally meet to mate.

Their call is produced at a very low part of the frequency spectrum, at between 15 and 30 Hertz, because water is a good carrier of low-frequency noise.

By contrast, human voices are in the frequency range of 80 to 1100 Hertz. This means that we would feel a blue whale’s song rumbling through our bones more than we would hear it.

Meanwhile, the loudest-mouthed land-based animal is one of our near relatives: the howler monkey.

These large New World monkeys live high in the upper canopies of jungles, ranging from southern Mexico down to northern Argentina.

The howler’s screaming starts at 90 decibels and rises, and can be heard three miles away through dense tropical foliage. The high volume is achieved thanks to the unique anatomy of its throat.

Howlers have an outsized bone at the base of their tongue, which enables them to brace their tongue directly against their larynx and emit what sounds like a super-human scream.

It’s an excruciatingly loud noise which is used by male and female alike to ward others off  their territory.

Meanwhile, anyone who has sat out in the tropics at night will know the identity of the world’s noisiest insect. Yes, it’s the cicada — which produces sounds up to 120 decibels.

These creatures use their drum-like stomach organs to make a sound which can be heard 440 yards away.

The world’s loudest cicada is the double drummer, from Australia, which has a six-inch wingspan and produces a noise that’s been compared to the bagpipes.

Also found in Australia is the superb lyrebird, thought to have the loudest bird call in the world.

This colourful  bird is only about the size of a chicken — but it’s an outstanding mimic. It has even been heard imitating the sounds of chainsaws, trains and babies crying.

But if you really want to know how to make a racket, take note from the pistol shrimp.

By snapping its large claw together, this tiny shrimp is capable of making a noise at least as loud as a whale. Some estimates say that it can hit 200 decibels.

The pistol shrimp uses its vocal power to stun prey — chiefly small fish and other shrimps.

When the shrimp snaps its claw shut, a jet of water spurts out at a velocity of up to 62 mph.

This causes the pressure around the jet to drop, allowing a naturally occurring air bubble in the water, called a cavitation bubble, to swell.

The bubble generates huge acoustic pressures strong enough to kill small fish. The cracking sound is louder than a gunshot and has been known to interfere with ships’ sonar navigation.

Pound for pound, the pistol shrimp may be the loudest animal in  the world.

To put all this in perspective, the Mail article wraps up with an account of the loudest burp by a human female, 107 decibels at a beer festival (where else?) in Italy.

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