Researchers from the University of Durham conducted a research on orangutan in Indiana Polis Zoo and found that the animal can have the ability to actually control their voice including the pitch and tone.

The study started back in 2012 when Rocky the orangutan was still eight years old. Using a game called 'do as I do', scientists found that Rocky was able to copy the voices made by human. The team also found that it included rhythm and pace similar to human speech.

Comparing the result with more than 120 orangutans in the wilds and zoos, the researchers found that Rocky's ability to imitate is not present in the others.

Rocky orangutan is able to replicate sounds and control his pitch and tone

Lead researcher Adriano Lameira speculated that there might be an evolution process that shows humans derived from ancestors with the similar voice control capacity.

Lameira who has joined the team since 2015 explained that this study can give scientists clues on early human speech. Before this study was done, scientists assumed that humans have to firstly master the vocal cords. And the human speech is probably the result of vocal system evolutions in early hominids. However, after analyzing Rocky's performance in the game, this can unlock the origin of language back since ancestral great apes, CBS News reported.

Great apes might have the ability to control vocal cords for conversation

In the video below, Rocky is given snacks as a reward after being able to copy the sound that the scientist makes. The orangutan surprisingly can change the tone and pitch of his voice to match the human speaking to him. This also means that they are not just making sounds uncontrollably.

Currently, Rocky is 11 years old and still lives in Indianapolis Zoo. Researchers are still examining the vocal control of orangutans to better understand how human speech evolved.

Read more