This image shows Ashley Stoeger and Daniel Mietchen recording Koshik's vocalizations at the Everland Zoo in South Korea. Credit: Current Biology, Stoeger et al.

An Asian elephant named Koshik can imitate human speech, speaking words in Korean that can be readily understood by those who know the language. The elephant accomplishes this in a most unusual way: he vocalizes with his trunk in his mouth.

The elephant's vocabulary consists of exactly five words, researchers report on November 1 in , a Cell Press publication. Those include "annyong" ("hello"), "anja" ("sit down"), "aniya" ("no"), "nuo" ("lie down"), and "choah" ("good"). Ultimately, Koshik's language skills may provide important insights into the biology and evolution of complex vocal learning, an ability that is critical for and music, the researchers say.

"Human speech basically has two important aspects, pitch and timbre," says Angela Stoeger of the University of Vienna. "Intriguingly, the elephant Koshik is capable of matching both pitch and timbre patterns: he accurately imitates human formants as well as the of his trainers. This is remarkable considering the huge size, the long , and other anatomical differences between an elephant and a human."

This video shows Koshik, "an elephant that speaks Korean," interacting with his trainer. Following vocal interaction with the trainer is documented: Koshik: "choah" (good), Trainer: "choah choah annyong" (good good hello), Koshik: "choah" (good), Trainer: "choah choah annyong" (good good hello), Koshik: "choah" (good), Trainer: "choah choah" (good good), Koshik: "choah" (good), Trainer: "annyong" (hello), Koshik: "choah" (good), Trainer: "annyong" (hello) Credit: Stoeger et al., Current Biology

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. A structural analysis of Koshik's speech showed not just clear similarities to , but also clear differences from the usual calls of elephants.

There have been some earlier reports of in both African and Asian elephants. have been known to imitate the sound of truck engines, and a male living in a zoo in Kazakhstan was said to produce utterances in both Russian and Kazakh, but that case was never scientifically investigated.

This is a recording of Koshik imitating human speech: Trainer (first) and Koshik (second) producing "annyong"(hello) Credit: Stoeger et al., Current Biology

In the case of Koshik, Angela Stoeger, Daniel Mietchen, Tecumseh Fitch, and their 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.

It's not completely clear why Koshik adopted his unusual vocal behavior, but the researchers suggest that it might go back to his days as a juvenile. 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.

More information: Stoeger et al.: "An Asian elephant imitates human speech." DOI: 10.1016/j.cub.2012.09.022

Journal information: Current Biology

Provided by Cell Press