We all know that parrots can imitate human language, and some have even seen elephants, seals or whales make “voices” like humans, so why can’t our close relatives speak like humans?
Chimpanzees are the most similar primates to humans. Most of them live in the forests of Africa. They like to live in groups of dozens of them. They have a very complex organizational structure and are generally used to hunting in groups.
There is a lot of evidence that they are the closest animal to humans and the most intelligent animal in existence today outside of humans.
A large number of research data show that they can use 66 different movements to communicate with each other, and the trained chimpanzees can not only master certain techniques, sign language, but also use the keyboard to learn some simple vocabulary, and even surpass them in practical ability. two-year-old child.
But no matter what they are or what kind of training they have, chimpanzees have never been able to speak aloud in human language, which has become a major topic for scientists studying chimpanzees.
“They haven’t developed or evolved language,” says evolutionary biologist Mark Bykov of the University of Colorado Boulder.
At the same time, American scientists also found that chimpanzees, like humans, can laugh when they are tickled, but unlike humans, they can breathe while laughing, which sounds like the sound of chainsaws running, while humans are talking or Breathing is temporarily stopped while laughing.
This is because the vocal organs of chimpanzees are different from those of humans, so the laughter of chimpanzees is a bit strange.
In addition, because chimpanzees and humans control vocalization differently, it is difficult to make some complex vowels and consonants like humans.
At the same time, because their vocal cords are relatively rigid, they cannot control the various parts of the diaphragm and muscles related to vocalization as well as humans, and can only instinctively make some roars or “grunts”.
So the physical reason is one of the factors that prevents them from speaking like humans.
Although chimpanzees’ physical structure prevents them from adjusting their vocalizations in the same way as humans, it is possible if they have cognitive and thinking skills and continuous training.
Scientists believe that the key to their inability to speak is that the nervous system of the brain cannot control airflow very well. Humans can speak by breaking through this limitation, but chimpanzees have no such ability.
The reason why parrots can speak, the secret lies in its special physiological structure – syrinx and tongue.
Although they can speak, the parrot’s vocal tract is different from the human vocal fold. The parrot’s vocal tract is called the vocal tract, which is located at the junction of the trachea and the bronchi. Three pairs of deformed bronchi form together.
Ordinary birds can make sounds of different frequencies and heights, because when the airflow enters the syrinx, it makes different sounds as the wall of the syrinx vibrates.
In addition to the most basic bird characteristics, the parrot’s vocal organ has a more complete structure than ordinary birds. There are four or five pairs of special muscles in its vocal tube that adjust the diameter, sound rate, and tension of the vocal tube— -Sound muscle, under the control of the nervous system, the sound muscle contracts or relaxes and makes a sound.
The syrinx is also very similar to the human vocal cord structure, except that the human vocal cord is 20 cm from the throat to the end of the tongue, which is a right angle, while the parrot’s syrinx is 15 cm from the end of the tongue, which is an obtuse angle that is close to a right angle. And this angle is the key to determining the syllable and tone of pronunciation. The closer to the right angle, the stronger the sense of syllable and tone of the pronunciation.
Therefore, language is unique to humans. The reason why parrots can learn tongue is because it has a syrinx that is similar to human larynx and vocal cords.