Scientists’ analysis of the monkeys’ grunts, barks, ‘wahoos’, ‘yaks’ and copulation calls could have major implications for the evolution of language.
Scientists from the National Center for Scientific Research (CNRS) and Grenoble Alpes University, both in France, and their colleagues recorded baboons in captivity, finding the animals were capable of producing five distinct sounds that have the same characteristic frequencies as human vowels.
Writing in the journal PLOS ONE, Dr Louis-Jean Boë and colleagues said: “Language is a distinguishing characteristic of our species and the course of its evolution is one of the hardest problems in science.
“It has long been generally considered that human speech requires a low larynx, and that the high larynx of non-human primates should preclude their producing the vowel systems universally found in human language.
“Examining the vocalisations through acoustic analyses, tongue anatomy and modelling of acoustic potential, we found that baboons produce sounds sharing the f1/f2 formant [sound frequencies] structure of the human vowels.”
They said their research confirmed that hominoids like baboons were capable of making contrasting vowel qualities despite their high larynx.
And Dr Boë, of Grenoble Alpes University, France, argued this had significant implications for the beginnings of the languages spoken by people today.
Previously it was thought that the spoken word originated sometime within the last 70,000 to 100,000 years.
However the researchers wrote in the PLOS ONE paper that their findings suggested “spoken languages evolved from ancient articulatory skills already present in our last common ancestor with Cercopithecoidea, about 25 million years ago”.
As part of their work, they listened to some 1,335 spontaneous vocalizations produced by 15 male and female Guinea baboons in different social contexts.
They also studied the anatomy of vocal tracts from two baboons after they had died of natural causes.
Humans are able to make vowel sounds because they can precisely control the position of the tongue.
The anatomical examinations of the baboons’ tongues found they had the same muscles found in humans, suggesting they use a similar technique.