Sperm whales are among the loudest living animals on the planet. They produce creaks, bangs, and clicks to communicate with other cetaceans that are a few meters or hundreds of kilometers away.
This symphony of sperm whale sounds is sophisticated enough to qualify as a full-fledged language. But will humans ever understand what these whales are saying?
The answer is: maybe
Before deciphering the language of the whales, researchers must collect and analyze an unprecedented number of communications between sperm whales, this is little but certain.
With a brain six times larger than ours, sperm whales (Physeter macrocephalus) are whales with a complex social structure, which spend much of their time socializing and exchanging messages. Sequences of messages that can be short (like 10 seconds) or last more than half an hour. Indeed, “The complexity and duration of whale vocalizations suggest that they are at least theoretically capable of exhibiting complex grammar” compared to other non-human animals.
This is what we read in an April 2021 paper on whales published on arXiv.org.
What does this study say?
This document, from an interdisciplinary project known as CETI (Cetacean Translation Initiative), outlines a plan to decode the vocalizations of sperm whales, first by collecting recordings of these whales, and then using machine learning to try to decode the sequences they use to communicate. CETI chose to study sperm whales over other whales because their clicks have a Morse code-like structure, which artificial intelligence (AI) could more easily analyze.
Break the ice
What little we know about sperm whales we learned quite recently. It wasn't until the 50s that we noticed these whales making sounds. And for 20 years we didn't understand that they used these sounds to communicate.
With a dual purpose, however. Sperm whales can dive to depths of 4.000 feet (1.200 meters). IS three times deeper of nuclear submarines. It is pitch dark down there: therefore, these whales have evolved to search for squid and other food using these sounds also to locate themselves, like a sonar. This same type of sound is also used in their social vocalizations, although in that case the communication clicks are denser, according to the CETI document.
Understanding this was also difficult
Sperm whales have long been very difficult for humans to study. We now have the tools to be able to look deeper than ever before thanks to artificial intelligence, robotics and drones.
David Gruber, marine biologist and leader of the CETI project.
Pratyusha Sharma, a data science researcher for CETI and a doctoral candidate at MIT's Computer Science and Artificial Intelligence Laboratory, is very confident in recent developments in artificial intelligence and language models, such as GPT-3, which uses deep learning to build human texts or stories. Scientists hope these same methods can be applied to sperm whale vocalizations to construct their language. There is only one problem: these methods have a voracious appetite for data.
We have 100.000 registrations, but we need 4 billion!
The CETI project currently has records of around 100.000 whale clicks, painstakingly collected by marine biologists over many years, but machine learning algorithms may need around 4 billion of these clicks. To fill this gap, CETI is creating several automated channels for collecting sperm whale records. Methods include underwater microphones placed in waters frequented by whales, and microphones that can be dropped from flying drones. Even robotic fish that can follow and listen to whales without being noticed.
But even with all this data, will we be able to decrypt it?
Many of the machine learning algorithms have found audio more difficult to analyze than text. For example, it may be difficult to analyze where a word begins and ends. As Sharma explained, “Suppose there is the word “umbrella”. Is “om” the word? Or is it “nice”? Or is it an “umbrella”?” The barriers between spoken words are more ambiguous and less regular, and patterns may therefore require much more data to discover.
This is not the only difficulty CETI will face.
“Whether someone is from, say, Japan or the United States or wherever, the worlds we talk about are very similar; we talk about people, we talk about their actions,” Sharma said. “But the worlds that these whales live in are very different, right? And the behaviors are very different."
Also, from a 6-year study published in 2016 in the journal Royal Society Open Science, it is known that sperm whales even have dialects.
If this seems like enormous difficulty, think about going to the moon. These difficulties are precisely what makes the project so ambitious and worthy. What one whale says to another is today as dark as the waters they swim in, but it is a mystery that makes CETI very, very intriguing.
