Speech or the capability of structuring sounds into a comprehensible form of communication is the distinguishing mark between humans and animals. Although there are many animals who have evolved vocal tract capable of producing speech-like sounds, they are unable to modulate the sounds as to transform them into speech. However, a recent study proves that some primates’ vocal tract can produce vowel-like sounds, a fact dismissed by the scientific community in the past.
The theory which consolidated the fact that primates are capable of producing vowel-like sounds started from a simple taxonomy. As we know, humans possess what is called a low or lowered larynx. This anatomical feature is the embodiment of what we call the human voice – loudness, color, projection, and even emotions. The lower larynx is what allow our voice to produce speech-specific sounds.
On the other hand, primates have what is called a high larynx. Although this formation allows primates to produce various sounds, some of them even closer to human speech, it is unable to produce vowel-like sounds. This is the traditional theory which 86ed the primates’ ability to use speech-specific sounds.
However, a recent study performed by a team of scientists from the Grenoble Alpes University, France, proves that primates, especially baboons, can reproduce five distinct vowel-like sounds, despite their anatomical limitations.
To study how humans and primates are capable of producing vowel-like sounds, the French scientists turned their attention towards the science of phonetics. In speech, the larynx produces various sounds which have distinct frequencies. These vowel-specific frequencies are called formants, and, according to traditional beliefs, the primates’ vocal tract is not developed enough to reproduce the same frequencies.
However, the recent French study doesn’t only disprove the common belief but also shows that baboons are capable of producing five distinct vowel-like sounds. To make this determination, the team of scientists recorded a year-worth of baboon-specific sounds, and compared them to the frequencies produced by formants.
Their research proved that even though primates are still unable to master the intricacies of human speech, their vocal tract can produce five distinct vocal-like sounds. This also disproves the theory which stated that the primates’ primitive vocal anatomy deterred them from developing speech-related faculties
The team’s notes and results were published on the 11th of January, 2017 in the PLOS ONE scientific journal.
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