Nature is noisy. If you sit on a rock in a forest, on a mountain or in a field, you will commonly hear something chirrup or snuffle about. Even in the concrete city of Berlin, I'm often yelled at by flocks of thuggish sparrows living in bushes or lulled to sleep by nightingales that visit the German capital annually in May.
We know that cows moo with regional accents, monkeys make sounds that are specific to the threats they face, mice sing and crickets scream for sex.
And now new research suggests that "clicks" heard in sperm whale vocalizations are like vowels in human speech. It appears that sperm whales communicate with patterns of a-vowels and i-vowels.
Increasingly, scientists have been using AI tools to study animal vocalizations, especially complex communication systems.
Scientists use AI to study animal communication
There has been a boom in our understanding of animal communication in recent years, and we owe it partly to artificial intelligence (AI).
AI allows researchers to analyze huge amounts of audio data of animal calls in seconds that would take humans decades to sift through.
There are hundreds of AI tools for analyzing vocalizations of different species.
Kevin Coffey, a neuroscientist at the University of Washington, US, helped build DeepSqueak, a machine learning tool which decodes rodent chatter.
DeepSqueak picks out rodent calls from raw audio data, compares them to calls of similar characteristics, and gives insights into the animals' behavior.
"Rats use ultrasonic vocalizations (USVs). High pitched 50 kilohertz (kHz) calls have been described as similar to a laugh, but there are many types of these made in different positive situations, like play, courtship, or even during the rush of a drug hit," said Coffey.
Rats also have 22 kHz calls that are used in negative situations, such as when they feel pain or sickness. Coffey uses those frequencies to tell when an experiment is making his lab rats feel bad.
Humans can't hear these calls as they are outside the frequency range that humans can hear, but DeepSqueak and other tools can help us to decode them.
Since its introduction in 2018, DeepSqueak has been used to study rodent social behavior, drug use, autism, and more. It has also been modified for use with many other species, such as dolphins, monkeys, and birds.
Coffey said they used to analyze USV spectrograms by hand but that AI tools allow them to automate the process, so they save time. But it's still up to humans to decide what the vocalizations mean.
"AI and deep-learning tools are not magic. They are not going to suddenly translate all animal sounds into English. The hard work is being done by biologists who need to observe animals in a multitude of situations and connect the calls to behaviors, emotions, etcetera," he said.
Do animals have languages?
Communication is essentially the transmission of information. All animals communicate somehow — by smells, pheromones, behaviors and vocalizations.
But the idea animal languages is contested — partly because of how humans view language and what it does for us.
Yes, animals do have forms of language, as far as we know. But the dialogues of sperm whales or symbolic communications of monkeys don't come close to the richness of human language.
Language is a particularly advanced toolkit for communication that seems to be unique to humans, said Coffey.
Anthropologists say language is unique to humans because of its ability to create and sustain cultural beliefs, relationships, and identities.
Human language also allows us to express our inner thoughts and feelings for other humans to understand. We think other animals are unable to do that with their vocalizations and actions.
Some theories even suggest that human consciousness, the higher metaphorical version of consciousness, developed alongside our capacity for language.
"People argue about what exactly defines language and if some elements of animal communication are similar to [human] language. The rodents we study are certainly very social and very communicative. The vocalizations they produce are highly varied and carry different types of information, but I still wouldn't consider them a language," said Coffey.
