Human speech is just a miracle. When speaking, we synchronously engage about 100 muscles of the chest, neck, jaws, tongue and lips. Each muscle is a bundle of hundreds and thousands of muscle fibers. More neurons are used to control this entire economy than when walking or running. One motor neuron can drive 2, 000 muscle fibers in the gastrocnemius muscle. In contrast, the neurons that control the vocal cords control only one or two muscle fibers.
Each spoken word or simple phrase is characterized by one "pattern" of muscle movement. All the information you need to say the phrase "Good afternoon!" located in the speech area of the brain. However, this is not a hard program. If, for example, you injured your tongue or underwent a dental operation, the program changes to pronounce this phrase as accurately as possible under the new conditions.
The common word "Hello" can mean many things. The tone of the voice shows that the person is satisfied, bored, in a hurry, angry, sad, scared, angry. The intensity of the voice when pronouncing a phrase also matters - it can indicate irony, affection, support or ridicule. The meaning of this simple expression can change in a split second due to the complex coordination of all speech muscles.
A person can pronounce up to 14 sounds per second, while individual elements of the vocal apparatus - tongue, lips, jaws can move no more than two to four times per second.
Our ancestors had a primitive conversational system, including vocal, tactile and visual actions, similar to "communication" among animals. Speech appeared when a person got the opportunity to represent objects with the help of symbols and the desire to share this knowledge with fellow tribesmen. The first symbolic language appeared, according to scientists, two and a half million years ago, when Homo Habilis (dexterous man) began to make stone tools.
This activity played a key role in the development of human communication. The accuracy of speech intelligibility has gotten better and better, reaching almost the present level in Homo Sapiens 150 thousand years ago. The mouth, nose and pharynx have gradually evolved into a complex system where air is transformed into vowels and consonants through the movement of the tongue and lips. Moreover, the emergence of grammar and syntax was the result of an evolutionary process that began precisely with the simplest words and expressions.