Search Here

A rare African monkey makes a lip-smacking sound which surprisingly bears similarities with human speech and making them the only species known to use a speech-like rhythm, U.S. researchers said Monday.

Geladas, the primate which is found only in the remote mountains of Ethiopia, was observed by scientists to use an undulating rhythm of lip-smacks in friendly encounters, featuring rapid fluctuations in pitch and volume. Researchers who analyzed recordings of the vocalizations uncovered a structural rhythm that closely matched that of humans speaking.

According to the study published in the journal Current Biology, the scientists propose the finding is evidence lip-smacking could have been an evolutionary step toward human speech.

'Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is plausible,' said lead scientist Prof Thore Bergman, from the University of Michigan in Ann Arbor, US.

'It demonstrates that non-human primates can vocalize while lip-smacking to produce speech-like sounds.'

Geladas are a highly gregarious species with a large vocal repertoire, expressed using complex facial movements. Also known as the "gelada baboon," the species is mostly terrestrial, and spends much of its time foraging in grasslands.

Bergman first became interested in geladas when he began studying them in 2006. "I would find myself frequently looking over my shoulder to see who was talking to me, but it was just the geladas," he said in a press release. "It was unnerving to have primate vocalizations sound so much like human voices."

"Language is not just a great tool for exchanging information; it has a social function," Bergman added.

Watch Gelada lip smacks and wobbles video below: