Neanderthals, our closest ancient cousins, had developed the ability to perceive and produce sounds from human speech, according to a study published in Nature’s ecology and evolution.
The idea that Neanderthals were much more primitive than modern humans is outdated today. Three years ago, analyzes of several dozen skeletons had indeed suggested that they also treated their patients and came to the aid of pregnant women.
We also know that our old cousin, often portrayed as a bloodthirsty being, was ultimately no more violent than modern humans. More recently, we also learned that Neanderthal newborns had a similar weight to that of human newborns, indicating a likely similar gestational history.
New work today depicts new points in common between our two species.
A more complex hearing than we thought
The evolution of language is a long debated question in anthropology. In particular, many have wondered whether or not the human form of communication – spoken language – is also present in other species of hominids. For Neanderthals, it would seem so.
As part of this work, a team from the University of Alcalá (Spain) performed high-resolution CT scans of the skulls of five Neanderthals to create virtual 3D models of their ear structures. They also modeled these same structures in Homo sapiens and on the skull of a Protoneanderthal from about 430,000 years old, found on the prehistoric site of the Sierra d’Atapuerca.
The data collected was entered into a software model focused on auditory bioengineering. In doing so, the researchers were able to estimate the hearing abilities of the subjects studied up to 5 kHz, which encompasses most of the frequency range of modern human speech sounds. Compared to the Atapuerca fossil, the Neanderthals showed a hearing more closely resembling that of modern humans (between 4-5 kHz).
Capable of producing consonants
But that’s not all. As part of this work, the researchers were also able to calculate the frequency range of maximum sensitivity – known as the occupied bandwidth – for each species analyzed.
Concretely, a wider bandwidth makes it possible to use a greater number of easily distinguishable acoustic signals in the oral communication of a species. Again, the Neanderthals displayed greater bandwidth compared to their ancestors from Atapuerca, more closely resembling modern humans in this feature.
Finally, last interesting point: it also emerged from these works that the Neanderthal speech probably included a increased use of consonants. In other words, he was not able to produce only vowels, as was previously thought.
This is a very important difference, as the use of consonants is a way to include more information in the speech signal. In addition, our ability to produce consonants is also what distinguishes human language from the modes of communication developed by almost all other primates.
An increasingly complex co-evolution of behaviors
In other words, this study shows us that our former cousins had a communication system as complex and efficient as us. “It is one of the most important studies in which I have participated in my career”, explains anthropologist Rolf Quam of Binghamton University. “The results are solid and clearly show that the Neanderthals had the ability to perceive and produce human-like speech“.
That doesn’t necessarily mean Neanderthals had the cognitive ability to do so, the researchers warn. However, they were physically capable of it. Thus, the study provides strong evidence for the coevolution of increasingly complex behaviors and increasing efficiency of voice communication throughout human evolution.