2 million-years-old fossils reveal what our ancestors` hearing was like

They have the range of about 1.0-3.0 kilohertz, which is better than previous human species. It suggests that they had sharper hearing in certain frequencies, and the hearing pattern resembles that of chimpanzees.

Two-million-year-old fossils including the three tiny bones of the middle ear are helping scientists figure out the auditory abilities of early human ancestors at a time when they were beginning to hear more like a person and less like a chimpanzee.

Research posted on Friday related to couple of group from South Africa, Australopithecus africanus and Paranthropus robustus, confirmed they will talked better hearing when compared to either chimps or those in a volume vary that have helped speaking conversational skills within the savanna territory. The team made the conclusion after reconstructing the internal anatomy of the ears of the two species of human ancestors. To do so, the researchers used Connecticut scans and virtual computer reconstructions based on fossils.

Modern humans can hear a wider range of frequency, between one and six kHz, than other primates.

Millions of years ago, ancient humans hear different sounds compare to what we hear today. While these ancient humans would not have had the capacity for language, scientists believe that they would have been producing meaningful vowel-based calls. “These are considered “voiceless consonants” because the vocal chords do not move when they are produced”.

Past studies have show 430,000-year-old Sima hominins (later Neanderthals) had identical hearing patterns to modern day humans, but the earlier South African specimens have now been shown to have had much more primitive hearing. Apparently, in more open, sprawling habitats, sound waves do not travel as far unlike in the rainforest, which means that short communication ranges are more ideal on the savanna. According to Live Science, the study results suggest that human ancestors had greater sensitivity to some high frequencies because of the difference in anatomy.

Quam said that we are not discussing on the matter that the human ancestors had language or not, might be they communicate vocally.

Computer simulations have illustrated how humans’ ancestors used these frequencies to initiate short-range communication at a distance of 23 meters. They have found that human ancestors consumed plants that could only be traced in the savanna 2 million years ago. In this same frequency range however, chimpanzees and mostly other primates can lose their hearing sensitivity since this range encompasses sounds the spoken language of humans.

Quam and his colleagues think the new findings have contributed to the better understanding of humans’ hearing and speech apparatus.