Researchers from an Austrian university have confirmed that an Asian elephant, Koshik, at a South Korean zoo can reproduce human speech in Korean but it does not exactly mean what it says.
The pachyderm accomplishes this in a most unusual way: he vocalizes with his trunk in his mouth. Its vocabulary consists of exactly five words, "annyong" (hello), "anja" (sit down), "aniya" (no), "nuo" (lie down) and "choah" (good).
"Human speech basically has two important aspects, pitch and timbre," says study co-author Angela Stoeger of the University of Vienna, the journal Current Biology reports.
"Intriguingly, Koshik is capable of matching both pitch and timbre patterns: he accurately imitates human formants as well as the voice pitch of his trainers," says Stoeger.
"This is remarkable considering the huge size, the long vocal tract, and other anatomical differences between an elephant and a human," adds Stoeger, according to a Vienna statement.
For one thing, Stoeger says, elephants have a trunk instead of lips. While their large larynx can produce very low-pitched sounds, Koshik's speech mimicry exactly copies the pitch and other characteristics of his human trainers' voices.
Stoeger, Daniel Mietchen, Tecumseh Fitch and colleagues confirmed that Koshik was imitating Korean words in several ways. First, they asked native Korean speakers to write down what they heard when listening to playbacks of the elephant's sounds.
"We found a high agreement concerning the overall meaning, and even the Korean spelling of Koshik's imitations," Stoeger says. But as far as the scientists can tell, Koshik doesn't actually mean what he says.
Koshik was the only elephant living at the Everland Zoo in South Korea for about five years, during an important period for elephant bonding and development. Humans were his only social contacts.
"We suggest that Koshik started to adapt his vocalizations to his human companions to strengthen social affiliation, something that is also seen in other vocal-learning species - and in very special cases, also across species," Stoeger says.