How Do Whales Communicate and Make Sounds Under Water? Latest Science


Whenever I listen to the song of a Humpback whale, I am captivated by the eery quality of the complex sounds. There’s no doubt that whales are highly intelligent creatures that regularly communicate with one another.  In this article, I well dive deep into the biology of whale communication.

Whales communicate primarily through complex sounds, including clicks, chirps, whistles, and intricate songs.  Whales do not have vocal cords. They produce sound by squeezing air through the larynx or through complex systems of air sacs and specialized soft tissues.  Whales can also produce sound by slapping parts of their body, such as flukes and tail, against the water surface.  There’s good evidence to suggest that whales and dolphins can identify one another based on the sounds they make. 

There are about 90 species of whales, dolphins, and porpoises, known collectively as “cetaceans”.

Cetaceans can emit and hear sounds in a much wider range of frequencies than we humans can.  For example, dolphins utilize clicks at frequencies as high as 110 kHz.  The average human, by comparison, cannot hear sounds above 20 kHz.

Humpback whales produce songs that last several hours. Blue whales and fin whales produce low frequency sounds that can travel 2,000 miles (3,200 km) or more. Sperm whales produce the loudest sounds of any animal; up to 230 decibels.

Toothed whales and dolphins, such as sperm whales and killer whales, have particularly large and complex brains.  Researchers believe that the complex intelligence of toothed whales has evolved over millions of years because of the complex social life and highly communicative lifestyle of these predators.

How do Whales Communicate Underwater?

Sound travels 4.5 – 5 times faster through water than through the air. Whales and dolphins have evolved to communicate primarily via sound and live largely in an acoustic environment.

Whales don’t have vocal cords, but they can still produce an amazing range of sounds, far beyond the range of frequencies that human can hear.  Dolphins can make clicks that reach frequencies as high as 110 kHz, while our hearing is limited to 20 kHz.

Cetaceans have a different physiology for producing sound, compared to the way we humans produce sound.  Instead of vocal cords, whales produce sounds by squeezing air through their larynx as well as through complex systems of air sacs near the blowhole.  The air sacs are used to produce the high frequency clicks used in echolocation.

The sperm whale uses the nasal passages in its massive nose to squeeze air through two fleshy ‘lips’ called “monkey lips” at the front of its nose just below the blowhole.  Using the lips, it can make loud clicks that are amplified in the oil-filled spermaceti organ.  The whale shoots the clicks out through the nose in highly directional sound beams that they can aim, like we aim a flashlight in the dark.

The clicks are so loud, that sperm whales can hear one another hundreds, perhaps even thousands of miles away.

How Loud are Whale Sounds?  Can a Whale Click Kill You?

Sperm whales are so loud that the clicks could potentially kill a human within close range of a few feet.

Sperm whales are the loudest mammals on the planet, with clicks that can reach a mind-blowing 230 decibels. In comparison, a jet engine produces about 140 decibels when measured 100 feet away.  Your eardrums would burst at around 150 decibels, and the threshold for death is estimated to be in the range of 185 to 200 dB.

James Nestor, an avid ocean-adventurer, author, and speaker, relates the experience of swimming alongside a pod of sperm whales and feeling the clicks vibrate inside his body.

“These clicks are so powerful in the water that they can blow out your eardrums easily, and they can actually vibrate a human body to death,” he said.

Loud sounds carry even more punch when traveling through water, since the water is much denser than air.  Sperm whale clicks are far more amplified in the ocean than they would be on land.  A sperm whale’s click of 200+ dB in the water would ‘only’ be 174 dB in the air. 

Considering that sperm whale clicks are loud enough to rupture a person’s ear drums, close contact with these creatures doesn’t sound like a great idea. But that won’t deter scientists with a passion!

Watch this short video for a glimpse into the world of sperm whales, complete with the sound of their clicks.

How do Whales Use Echolocation?

Most of the toothed whales use echolocation to find their prey, often in the pitch black of the deep ocean. Echolocation consists of a series of clicks that the animal aims forward from its snout, with the ability to receive even the faintest of echoes as the sound waves bounce off objects, plants and animals and return to the originator of the clicks.

According to the Smithsonian Museum, sperm whales can use echolocation to detect a small squid less than a foot long more than a mile away, and schools of squid from even farther away.

Graphic showing how sperm whale can focus it clicks like an acoustic flashlight. Credit Te Papa Museum NZ

Animals that use echolocation for hunting, such as the sperm whale, will often increase the speed of the clicks to achieve higher resolution and a more detailed ‘picture’ of its prey as they get closer. Just before the prey is captured, the clicks blur together, reminding us of the sound of a “creaking” door.

Here’s an excellent video from the Museum of New Zealand Te Papa Tongarewa showing how Sperm whales use echolocation to hunt giant squid. We can see how the whale uses echolocation like an acoustic flashlight.

How do Whales and Dolphins Hear?

Whales and dolphins don’t have external ears.  They use their jawbones for hearing.

Whales and dolphins have ears, but their ear canals do not open to the outside.  They don’t have external ears that stick out like ours do. 

Whales and dolphins generally hear sounds through special structures in their jawbones, with fatty lobes near the jaw being connected to the inner ear. 

Once the vibrations reach the inner ear, neural impulses are sent to the brain.

Reminds me of a kid’s ditty: jawbone connected to the earbone, earbone connected to the nervous system, nervous system connected to the brain…

Can Whales and Dolphins Identify One Another by Sound?

Yes, there’s good evidence to suggest that whales and dolphins can identify one another based on the sounds they make. 

Take the bottlenose dolphin, for example.  Scientists have found that each bottlenose dolphin develops a its own distinctive signature whistle (Tyack, 2000).  Each unique whistle appears to serve as a means of individual identification.  

Bottlenose dolphin. Photo credit NOAA

Just as we refer to one another by name, each dolphin identifies itself by using its own unique whistle and copying the whistles of other individuals, as if calling them by name. Dolphins will often whistle to another dolphin, with the other dolphin moving toward the whistler. Dolphins also whistle when separated from their family group. If they become separated, a young calf and its mother will whistle repeatedly until reunited.

Dolphins are the only animals other than humans that have been shown to transmit identity information independent of the caller’s voice or location (Janik 2006). 

Not only do these dolphins call each other by name, they can remember the whistles of other dolphins after 20 years of separation. Research from the University of Chicago shows that dolphins have the longest memory of any species other than humans (that we know about).

Wouldn’t it be fascinating to learn how bottlenose dolphins refer to themselves?  The romantic non-scientist in me likes to think that they adopt catchy names like “Surf Rider” or “Shark Chaser” or “Bubble Brain” or “Tail of Steel!” OK, not “Bubble Brain.”

How do Whales Communicate Over Long Distances?

The large baleen whales, like blue whales and fin whales, produce very low-frequency sounds that can travel through the ocean for thousands of miles. 

In some species, notably the humpback whale, males can repeat long, complicated songs.  The standard hypothesis is that these songs appear to play a role in reproduction, by helping to attract mates and by sending signals to potential rivals. 

The latest science, however, is not so clear cut.  Some scientists, Dr. John Hildebrand, Scripps Institution of Oceanography, and Dr. Jim Darling, Whale Trust, for example, postulate that whales sing to convince other whales that they have certain characteristics that they want project.  

In other words, the power of the sound isn’t about propagating long distances as much as it’s about projecting a particular profile to other whales, which might include demonstrating a male’s dominance or fitness to mate.

Can Whales Communicate Visually?

Whales can communicate visually in ways that we don’t fully understand.  Take the killer whale (Orcinus orca), for example.  There are certain clans of orca known as transients that specialize in hunting marine mammals, including seals, sea lions, and other whales.  In marked contrast to the hunting style of most toothed whales that hunt using echolocation, including clans of fish-eating orcas, the transient orcas have developed the ability to hunt cooperatively in silence. Silent hunting allows these killer whales to sneak up and ambush their prey, but it also means that they must be using visual signals to coordinate the hunt.

Since whales and dolphins live in an acoustic environment with greater dependence on sound processing, this is reflected in the structure of the brain.  In a cetacean brain the neural area devoted to visual imaging is only about one-tenth the comparative size of that in the human brain.  Conversely, the area of the brain devoted to acoustical imaging is about 10 times as large.

Whales Have Had Sophisticated Communication for Millions of Years

The largest brains that ever evolved on earth belong to whales.  Whales evolved big brains about 20 million years ago, many millions of years before early humans developed big brains (only about 1 million years ago).  What are some of the implications?

Whales and primates both show dramatic growth in the same two regions of the brain: the cerebellum and neocortex. Both regions are important for the higher cognitive functions involved in communication.

In 2006, scientists at the Mount Sinai School of Medicine reported that “sperm whales, killer whales and certainly humpback whales exhibit complex social patterns that include intricate communication skills, coalition formation, cooperation, cultural transmission and tool usage.” They noted that it is “likely that some of these abilities” are related to the comparable complexity of the brain structures possessed by both whales and hominids.

After analyzing the brains of both toothed and baleen whales, the Mount Sinai researchers found concentrations of spindle cells associated with higher cognitive functions.  In humans, these types of brain cells are involved with self-awareness, a sense of compassion, and use of language.

One of the amazing things is that whales evolved these highly specialized neurons millions of years before we humans did! 

This is a good example of parallel evolution, whereby physical traits that perform a similar function evolve independently in different species. 


Another good example of parallel evolution is the eye of the octopus, with the same complicated structure as the human eye. For more fascinating facts about Octopus read my popular article: Why do Octopus have 3 Hearts, 9 Brains, and Blue Blood? Smart Suckers! Yes – these amazing animals have 3 hearts and 9 brains!


Do Whales Develop Different Dialects?

Whales can develop various dialects much like humans. 

Take killer whales, for example.  We’ve learned that there are cultural differences among killer whales based on their vocalizations. There are four clans of “resident” orcas in the coastal waters of British Columbia and Washington State, each consisting of several pods. Even though the clans can share the same waters, their vocalizations are as different as English and Greek. And each pod has a dialect of its own, akin to the differences between the English spoken in Scotland vs Canada.

Photo of Orca whales
Orca whales off the Pacific coast. Photo by Nitesh Jain on Unsplash

One use of dialects among the orcas is to avoid inbreeding.  The males seek mates outside of their own pods, based largely on the differences in vocalization. 

Hal Whitehead, a marine biologist at Dalhousie University in Nova Scotia has been tracking and recording sperm whales around the globe since the early 1980s.  He has positively identified five distinct clan dialects that use different codas.

Codas are “Morse code-like pattern of clicks” that the whales use to communicate with one another.

Do Whales Have Unique Cultural Groups?

According to biologists, behavior is what you do, culture is how you do it.

All whales do the same things, such as communicating, swimming, feeding, defending themselves, and even babysitting.  But how they do these things varies, even within the same species.

We humans have different ways of eating – forks or chopsticks for example – and widely different food preferences.  Whales have similar cultural differences in terms of what they eat, how fast they travel, how far they roam, and much more.

Aerial photo of sperm whales taken during an Atlantic Marine Assessment Program for Protected Species survey. Photo: Tim Cole/NOAA.

Let’s consider sperm whales.  They live in elaborately structured clans which are large groups of thousands of individuals spread over many thousands of miles of ocean.

Within each clan there are smaller family units or pods. Young whales are raised within the pod by a network of female caregivers, including the mother, aunts, and grandmothers.  Sperm whales have a matriarchal society, and it is the females that pass along important lessons in communication, as well as hunting techniques, food sources, etc.

“It’s like they’re living in these massive, multicultural, undersea societies,” says Hal Whitehead, the world’s foremost expert on sperm whales. “Really the closest analogy we have for it would be ourselves.”

Can Whales and Dolphins Communicate with Humans?

Dolphins can learn human sign language and can use whistles for communicating with humans.

Research conducted at the Kewalo Basin Marine Mammal Laboratory in Honolulu, Hawaii on bottlenose dolphins, showed that they could learn to understand individual words and basic sentences.  Akeakamai, a female bottlenose dolphin, could carry out tasks in response to a sentence such as, “touch the frisbee with your tail and then jump over it” (Herman, Richards, & Wolz 1984).

This research shows that dolphins can learn sign language and understand the significance of the order of tasks in a sentence. Akeakamai was involved in many successful scientific studies of dolphin cognition, language acquisition, and sensory abilities.

Do Whales and Dolphins have Their Own Languages?

We don’t know if whales and dolphins are using what we might call language. The sheer complexity and abundance of the various sounds they make, does, however, make one wonder? What if…?!

Scientists have determined that whales can make “human-like” use of hierarchical syntax to communicate. In studying humpback whale songs, though, they’ve come to the conclusion that the sounds convey less than one bit of information per second. By comparison, humans speaking English generate 10 bits of information for each word spoken. 

But what if the human word is a poor comparison when it comes to whale communication?

Some people believe that the coda that whales and dolphins use are more akin to data transmission, such as fax machines, than they are to human language.  According to James Nestor, data is a much more evolved way of communicating, which why modern communications is digital, such as cell phones and the internet.

Researchers have measured 1,600 microclicks in a single second of sound being sent by one sperm whale to another.  And they can repeat the exact pattern of microclicks with great precision. Nestor believes this is a very deliberate signal. He believes that the sperm whale clicks represent encoded packs of information that are much more refined than the words we use in human language, which he considers “really clunky.”

“If I mispronounce something just slightly, you don’t understand me. Transmission of data is a much more precise.”

Nestor says, “If you’re diving with these animals, they’ll sit there in a circle and crane their heads in just the right way to shoot clicks to one another with a clear signal. It’s a pretty mind-blowing experience to be in the middle of. To see them conversing. There’s obviously something so powerful there.”

We have a long way to go in our understanding before we can say with certainty that whales are communicating using their own ‘language.’

Fun Facts

  • Bottle-nose dolphins have a signature whistle that they use as their own unique ‘name.’  They can call other dolphins by their ‘names’ and they can remember the ‘names’ of other individuals after 20 years!
  • Whales and dolphins don’t have external ears or vocal cords.  They use their jawbones for listening.
  • Sperm whale clicks are so powerful at 200+ dB that they can blow out human eardrums and potentially kill a human at close range.
  • The songs of whales were sent into space aboard the Voyager spacecraft to represent sounds from Planet Earth.
  • The Beluga whale is also known as the Sea Canary due to its high-pitched squeaks, squeals, and whistles.

Food for Thought

  • We know that whales have had large brains for millions of years.
  • We know that whales have complex communication abilities.
  • We search the universe for signs of intelligent life, but do we appreciate the intelligent creatures living on this planet?!

References

Herman, L. M., Richards, D. G., & Wolz, J. P. (1984). Comprehension of sentences by bottlenosed dolphins. Cognition, 16(2), 129–219. https://doi.org/10.1016/0010-0277(84)90003-9

Janik VM, Sayigh LS, Wells RS. Signature whistle shape conveys identity information to bottlenose dolphins. Proc Natl Acad Sci U S A. 2006 May 23;103(21):8293-7. doi: 10.1073/pnas.0509918103. Epub 2006 May 12. PMID: 16698937; PMCID: PMC1472465.

Nestor, James. Cetacean Echolocation Translation Initiative, CETI.  Independent research project focused on studying and attempting to comprehend sperm whale clicks.

Smithsonian National Museum of Natural History, Bigger Brains: Complex Brains for a Complex World https://humanorigins.si.edu/human-characteristics/brains

Tyack, Peter L., 2000, Dolphins Whistle a Signature Tune, Science, Vol. 289(584), 2000

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George Sranko

George Sranko, B.Sc., MA (Hons), is a retired professional biologist, photographer, author and speaker. He has explored fascinating nature topics and epic destinations for over 40 years, beginning with his first job as a National Park naturalist. George is a popular destination and science lecturer on cruise ships throughout the world, with hundreds of presentations under his belt. He has visited over 90 countries and happily shares his personal experiences and insights in a dynamic and entertaining style.

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