Animals as diverse as elephants and parrots can mimic the sounds of human speech. But can any of them understand what they are saying?
In April 2010, Adriano Lameira set up his video camera in front of an enclosure at Cologne Zoo in Germany. Inside was an orang-utan called Tilda.
There was a rumour that Tilda could whistle like a human, and Lameira, of Amsterdam University in the Netherlands, was keen to capture it on camera. But as the camera kept rolling, Tilda did much more than just whistle. She clapped her hands, smacked her lips, and let out a series of deep-throated human-like garbled sounds: almost like someone who had inhaled sulphur hexafluoride, a gas that makes your voice deeper.
Lameira was baffled. \”These were not only very different from whatever we have heard from wild orangutans so far, but we could also see some similarities with human speech,\” he says.
Tilda wasn\’t the first animal that seemed to be able to mimic human speech. A handful of other species also make noises that sound like talking, including elephants and beluga whales – to say nothing of parrots.
These animals seem capable of bridging the language barrier that separates us. And their attempts at speaking like us make them quite irresistible. But can they really \”talk\” as we do? It\’s not just a matter of being able to make the sounds. To really count as talking, the animals would have to understand what they mean.
Tilda was born around 1965, captured from the island of Borneo and raised in captivity. She is among the first of our closest cousins known to have successfully imitated human-like sounds.
Lameira\’s team found that her calls were strikingly similar to human speech. Their rapid rhythm precisely matched that of humans speaking. Moreover, she seemed to be stringing together vowel and consonant-like sounds. That is a precursor to how we build syllables, words and sentences, Lameira says.
Nevertheless, her calls are far from being a perfect imitation of our speech. But she is not the only mimic out there. Famously, parrots are good at, well, parroting.
The undisputed champion of speech mimicry was an African grey parrot called Alex. He was trained by cognitive scientist Irene Pepperberg of Harvard University in Cambridge, Massachusetts. Alex could quickly learn and imitate new English words. He could even say \”I love you\”, and wished Pepperberg good night after a hard day\’s training. When Alex passed away in 2007 at the age of 31, fans from all over the world mourned.
Other mimics use completely different mechanisms
So what makes parrots like Alex such proficient impressionists?
Part of the answer lies in their vocal tract, says Pepperberg. \”Their vocal tract\’s complex musculature, and their thick, yet flexible, tongue may help them produce human speech sounds more easily,\” she says.
However, other mimics use completely different mechanisms to make the sounds. Take Noc, a beluga whale at Vancouver Aquarium in Canada, whose speaking abilities were described in 2012. Captured young by Inuit hunters and raised in captivity till his death in 1999, Noc would over-inflate his nasal cavities to produce human-like sounds.
One elephant can also mimic human speech, using yet another method. Described in 2012, Koshik produces several words of Korean by placing the tip of his trunk into his mouth to modulate his vocal tract.
By doing so, he accurately matches both the pitch and timbre patterns of his trainers\’ voices, says Angela Stöger-Horwath of the University of Vienna in Austria. This is remarkable, she says, considering that elephants\’ vocal tracts are anatomically different from ours: they are longer, and they have a trunk instead of lips.