2 million year old fossil reveals how humans heard sound

Early humans who lived around two million years ago had hearing abilities similar to chimpanzees but with some slight differences in the direction of modern humans, new research that looked into ancient human fossils has revealed. They plan to carry out additional studies to find out how humans arrived at such a wide range of hearing frequencies (modern humans can perceive sounds ranging between 1 and 6 kHz). They hear differently compared with humans and chimpanzees being sensitive to close-range sounds. They were interested in finding out when this human-like hearing pattern first emerged during our evolutionary history.

A paleoanthropologist named Rolf Quam of Binghamton University in New York said, the species if we compare to that of chimpanzees are more inclined towards higher frequencies and have maximum hearing sensitivity.

“It turns out that this auditory pattern may have been particularly favorable for living on the savanna”. Sound waves can’t travel so far in open environments which is why short-range communication is usually favored rainforest canopy.

Next, researchers hope to determine how hearing went from a chimp-like pattern to a more human-hearing pattern.

A team of scientists led by a researcher at Binghamton University have used ancient fossils to reconstruct the internal anatomy of the ear of our early ancestors. This means that they could hear better and within a frequency range of 1.0-3.0 kHz. These fossils are about 430,000 years old and are considered to represent ancestors of the later Neandertals.

However, research also says that while the ability might have been similar, the physical aspects of the hearing organs between the chimpanzee and our early human ancestor might have been very different.

Quam also informs “We know these species regularly occupied the savanna since their diet included up to 50 percent of resources found in open environments”.

Did the early humans communicate vocally? These types of sounds are used in modern-day human communication – including the sounds made by the letters “K”, “T”, “Th”, “F” and “S” – and could have helped hominins detect short-range vocal communication during their time, the researchers said. “No”, said Quam. “We’re not arguing that. All primates do, but we’re not saying they had fully developed human language, which implies a symbolic content”.

He is careful not to suggest that Australopithecus or Paranthropus had anything resembling human language, which other evidence suggests came much later. In terms of how human ancestors communicated with each other, anthropologists believe that the small brain size and vocal tract of these individuals would not have given them the capacity for language.

The study was published on September 25 in the journal Science Advances.