No one's really sure what Neanderthals sounded like, or even if they could speak. But one Florida researcher thinks he can guess.

Robert McCarthy, an assistant professor of anthropology at Florida Atlantic University in Boca Raton, Fla., used ancient skeletons to reconstruct an approximation of the Neanderthal vocal tract — and then had a computer recreate the sounds it would make.

• Click here to listen to how McCarthy's computer figures a Neanderthal would have pronounced the flat 'e' sound.

"They would have spoken a bit differently," McCarthy tells New Scientist magazine. "They wouldn't have been able to produce these quantal vowels that form the basis of spoken language."

McCarthy explained quantal vowels as sounds that are recognizable as "a" or "o," for example, no matter how high- or low-pitched the speaker's voice is.

Neanderthals' inamility to produce these vowels would have severely limited their ability to form and understand a complex language, McCarthy argues, though Erik Trinkaus of Washington University in St. Louis, one of the world's leading experts on Neanderthals, disagrees.

"Ultimately what is important is not the anatomy of the mouth, but the neuronal control of it," Trinkaus tells New Scientist, pointing out that Neanderthal brains were larger than those of modern humans, and that both species shared a gene essential for language.

• Click here to visit's Evolution & Paleontology Center.

Furthermore, some languages place less emphasis on vowels than others. Although English and French have about a dozen vowels each, Hebrew has only five vowels and Arabic three.

That doesn't mean a Neanderthal could speak Arabic well, but at least it'd be easier for him than Hawaiian, which has up to 25 vowels, depending on how you count them.

Neanderthals were a separate human species that lived in Europe from about 300,000 to 30,000 years ago.

• Click here to read the full New Scientist story.