AI breakthroughs unlock secrets of orangutan conversations

The dream of understanding animal speech is coming true – thanks to technological progress – before our very eyes. After years of experiments with monkeys using sign language or communication with dolphins, the time has come for a new generation of translators. These are algorithms that study the complex language of orangutans.

Orangutans are among the animals whose way of communicating is the most complex. Research conducted on them has led to questioning the notion of the uniqueness of human speech.

Dr Adriano Lameira from the University of Warwick points out that humans use lips, tongue, and jaw to articulate voiceless consonants, activating the vocal cords (folds) in the larynx with exhaled air for vowel articulation. Orangutans can also produce both types of sounds simultaneously.

The discovery of anatomical mechanisms responsible for the communicative abilities of some monkeys – especially orangutans – has also led to a revision of views on the origin of human speech.

The beginnings of communication through controlled, conscious sound production may be as old as the common ancestors of humans and great apes. Research on orangutans, for example, indicates this, among other things. They communicate in an unusual way—they can, which is rare in the animal world, produce two sounds at once.

""Humans rarely produce voiced and voiceless noises simultaneously. The exception is beatboxing. But the very fact that humans are anatomically able to beatbox, raises questions about where that ability came from. We know now the answer could lie within the evolution of our ancestors," notes Dr. Madeleine Hardus of the Pongo Foundation.

While the ability to produce certain sounds has a genetic basis, researchers believe that the development of language itself was primarily influenced by social conditions. This is indicated by studies confirming that it is the community that shapes the vocal abilities of orangutans.

But what exactly do Bornean monkeys talk about? Although there have been successful attempts to understand and even have conversations with different mammals, a breakthrough is happening before our eyes, thanks to artificial intelligence.

New research published in the journal PeerJ Life & Environment sheds light on the complexity of Bornean orangutan vocalisations.

"Our research aimed to unravel the complexities of orangutan long calls, which play a crucial role in their communication across vast distances in the dense rainforests of Indonesia. Over the course of three years, we accumulated hundreds of long call recordings, revealing a fascinating array of vocal diversity," says Dr. Wendy Erb from Cornell University in the USA.

Researchers used traditional sound analysis methods and machine learning tools such as Uniform Manifold Approximation and Projection (UMAP - Manifold Embedding Space Clustering) to decipher orangutan conversations.

After recording over 3,800 hours, they examined 117 long calls from 13 orangutans separated from the rest of the group. Based on this, they identified as many as 1,033 distinct sounds, whose sounds can be distinguished by both the algorithm and the human ear.

Although the content of the messages is not yet known, scientists note that the orangutan language appears to exhibit much greater "potential complexity" than previously thought. Moreover, another study indicates that some monkeys deliberately use distorted sounds, which researchers liken to slang.

This confirms the richness of sounds conveyed during a single call, during which monkeys – researchers believe – can convey not only superficial information, e.g., about food or threats but also complex, detailed messages.