Language has been one of the most significant evolutions of human history. Without speech, communication between people would have been limited, preventing the progress that has occurred over the past thousands of years. But have you ever wondered how the human speech mechanism works?
Speech and human beings
There are two aspects to human speech. The first is the physical structure that enables it. The second is the sound/pronunciation system that results in the creation of sentences. The lungs, voice box, vocal tracts, tongue, and lips comprise the physical structure of the speech system, while vowels, consonants, syllables, and words form the sound/pronunciation system.
“To pronounce words, we push air from our lungs up through our throat and vocal cords, through our mouth, past our tongue and out between our teeth and lips… To change the sound that we are making, we mainly use the muscles of our mouth, tongue and lips to control the shape of our mouth and the flow of air. If we can control the shape of our mouth and the flow of air correctly, then our pronunciation is clearer and other people understand us more easily,” according to English Club.
To pronounce vowels, air is allowed to flow freely as it travels through the mouth. For consonants, air is blocked as it travels through the nose or mouth. To block the air, physical structures like lips, teeth, the tongue, the back of the throat, and the top of the mouth are used either individually or in combination with each other. A syllable is a unit of pronunciation that has a vowel sound with or without surrounding consonant sounds. A word is created from one or more syllables, with each word specifying a meaning. Multiple words are finally stitched together to create sentences, thus forming a coherent speech mechanism.
Humans vs apes
Given that humans and apes have so many similarities, why is it that we alone are capable of speech while our cousins in the animal kingdom have yet to evolve a complex speech system? The answer to this might lie in the brain, according to a study published last year in Frontiers in Neuroscience. Zoologist Jacob Dunn and co-author Jeroen Smaers ranked 34 primates on the basis of their vocal ability, judged according to the distinct number of calls they make.
The “more vocally adept apes… had relatively large areas of the brain known as cortical association areas — essentially brain regions which receive sensory input and decide what to do with it… bonobos and the other more vocal apes — including chimpanzees — had much larger parts of the brain dedicated to control of the tongue… while our primate cousins may well be sufficiently smart to develop and understand complex ways of communicating, the voluntary control of their ‘vocal apparatus’ — rather than their intelligence — is the limiting factor,” according to the BBC.
It is thought that since human beings placed higher importance on vocal communication, certain regions in the brain evolved to fulfill these needs. In contrast, apes had a different set of priorities that did not include complex vocal communication. As a consequence, apes remain limited to rudimentary forms of communication while human beings developed complex, systematized speech and languages.
However, this does not mean that apes and other animals will never be able to communicate with us in our language. Scientists are currently working on tech that could translate animal communication to human language through the use of AI. This tech could hit the market in as little as 10 years.