Humans use the same basic biological apparatus to make noises as chimps, lungs, throat, voice box, tongue and lips. So why are we the only ones that articulate words, talk on the phone and sing songs? Through evolution humans have developed a longer throat and smaller mouth better suited to shaping sounds, furthermore we have developed a flexibility in our mouths unique to us that allows us to make a wide range of very specific sounds.
When we talk we produce small controlled bursts of air that are pushed through our larynx, or voice box. The larynx is made of cartilage and muscle, there are two folds of mucus membrane stretched across the top, these are the vocal cords. When air is pushed through the folds vibrate, producing sound. We change the pitch of our voices by tightening the cords, and loosen them to make a lower sound.
Producing sentences is a very complex process, it involves a collaboration between the throat, tongue and lips to emit specific consonants and vowel sounds.
‘Speech is the most complex motor activity that a person acquires except from maybe violinists or acrobats etc. It takes about 10 years for children to get to the level of adults. ‘
–Dr. Philip Lieberman
If you look back at human evolution, after we diverge from an early ape ancestor, the shape of our vocal track changed. Our mouths got smaller, we developed more flexible tongues and our necks got longer. Our larynx got pulled down into the throat, the extension was a way to make room for all of this vocal equipment. This very important development in the human body came at a price. As a result, when humans eat the food must pass by the larynx to get to the Oesophagus, this can sometimes get mixed up and this is why people choke to death.
One of the main differences between humans and chimps when it comes to the production of language is breath control, humans can control their breath to a very high degree, whereas chimps can only produce short bursts of air.