The team also admits that 'monkey talk' might not sound anything like human talk, but the vocal ability to shape five vowels and several common consonants is there. They say that by using living monkeys rather than the cadavers analysed for past studies, their findings are far more accurate. Credit: Tecumseh Fitch and Asif Ghazanfar Monkey vocal anatomy (left), X-ray used in the study (right). In this case, the scientists went deeper than previous research from the '70s, using X-ray videos to record 99 different vocal tract outlines, including those used in monkeys' threat calls, lip smacks, yawns, and when feeding. 'Our findings imply that the evolution of human speech capabilities required neural changes rather than modifications of vocal anatomy.'

'For four decades, the inability of non-human primates to produce human speech sounds has been claimed to stem from limitations in their vocal tract anatomy, a conclusion based on plaster casts made from the vocal tract of a monkey cadaver,' the team explains in their paper. Researchers from Princeton University and the University of Vienna in Austria say their work suggests a basic form of spoken language could have evolved at any point in the evolution of our primate relatives, with no changes needed in vocal anatomy.

Monkey sounds