An orangutan imitating his trainer’s calls could shed light on how human speech was first developed. A research paper published in Scientific Reports has unveiled that orangutans have the ability to learn sounds from humans and reproduce them at will.

Experiments carried out on Rocky, an orangutan who lives in the Indianapolis Zoo, have shown that the great apes like humans can choose when and how to use their vocal cords. Rocky used to choose when he has to make vocalizations.

Research fellow Adriano Lameira and his team said that Rocky can take out vowel-like calls by copying the pitch and tone of sounds made by the human researchers. Rocky used to imitate his trainer’s pitch and volume and reply to her in almost conversational matter.

There have been many studies that indicate that apes can understand language, including sign language. Researchers have compared Rocky’s sounds with the largest database that has ever been assembled of orangutan calls.

The data had more than 12,000 hours of observing 120 orangutans both wild and captive. The researchers came to know that Rocky’s sounds were having complete different frequency range. “We’ve demonstrated that apes are able to learn a new vocalization that is unknown in their species. We don’t know how he learned it, but he either innovated it on his own or was able to reproduce it, then learn it”, affirmed Robert Shumaker, Vice President of conservation and life sciences at the Indianapolis Zoo.

The research paper published in the journal Scientific Reports provides a new way to learn more about the vocal abilities of early hominids that lived before the orangutan and human lineages separated. The research findings could also see how the vocal system has evolved with full-blown speech in humans.