For years, researchers have known that rock artists didn't paint their bison, bears, lions and other images in random locations. Art tends to show up on places where echoes in rocky grottos and caves bounce back to listening human ears. That suggests there’s something about the acoustical landscape of caves that may have inspired or focused ancient artists. Archaeologists have even used the pattern as a way to find new cave art.

Inspired by this pattern, MIT linguistics professor Shigeru Miyagawa and a team of researchers from Tokyo and Brazil came up with an idea. What if cave art represented a way that early humans tried to communicate about the sounds they heard by visually representing what the echoes sounded like?

As Sarah Gibbens reports for National Geographic, the researchers examine the interplay between cave art and echoes in the caves where they are found in a new paper, published the journal Frontiers in Psychology.

In a press release, the researchers point out that cave art has a lot of features seen in language. “You have action, objects, and modification,” says Miyagawa. Drawings located in acoustic “hot spots” may represent a convergence of hearing information and then trying to represent it visually. They posit that this “cross-modality information transfer” may have helped ancient humans "enhance their ability to convey symbolic thinking."

But the researchers are quick to say that the study is only intended to serve as a working hypothesis (even the paper's subhead clarifies the idea is "A Hypothesis about the Relationship among Prehistoric Cave Paintings, Symbolic Thinking, and the Emergence of Language").

As April Nowell, a University of Victory archaeologist, explains in an interview with Gibbens of National Geographic, linking the development of language with ancient cave drawings is tough; various other factors could explain why cave art was produced where it was. For instance, Nowell says, cave art may have occurred in spaces where storytelling was already taking place, and may have served a decorative purpose. “I don’t think it was the only explanation for why people made marks in the places they did," she tells Gibbens.

After all, experts are still debating over what the earliest examples of art, themselves, even signify. As Andrew Curry reported in Smithsonian in 2012, is cave art straightforward representations of what people saw or was it more abstract — an example of symbolic thinking?

Absent more clear evidence that cave art represents intentional communication and symbolic thinking, experts will continue the search for the origins of language. But if we're ever going to crack the mystery, this study shows how important it is for researchers to get creative and rely on all their senses, including listening to the sounds of the past.