Human speech is a social phenomenon, not a biological one. By nature, humans have no organs of speech. But there is a speech apparatus - a set of organs necessary for the production of speech.
The human speech apparatus consists of organs, each of which has its own biological functions. For the production of speech sounds, the same conditions are necessary as for the production of sounds in general: a driving force, a body whose movements will give noises and tones, a resonator for the formation of the timbre of sounds. The source of production of most of the sounds of speech (driving force) is the air stream, which is pushed out of the lungs through the bronchi, trachea. Then through the pharynx and the mouth or nose outward. It turns out that the human speech apparatus resembles a wind instrument. Which consists of furs (in humans, they are the lungs), a tongue or other body capable of rhythmic vibrations, giving a tone (in humans, these are the vocal cords in the larynx), and a resonator (the cavity of the pharynx, nose and mouth). But the capabilities of the human speech apparatus are much greater than any instrument, as evidenced by a person's ability to onomatopoeia.
The entire speech apparatus is divided into three parts. Anything below the larynx. The larynx itself. Above the larynx. The lower part consists of the lungs, bronchi and trachea. It pumps the exhaled stream of air necessary for the formation of sounds using the muscles of the diaphragm. In the lower part of the speech apparatus, speech sounds cannot be formed.
The middle part - the larynx, consists of two cartilages that form the skeleton of the larynx. Inside it, in the form of a curtain, converging in halves to the middle, muscular films are stretched. The central edges of the curtain are called the vocal cords, which are highly elastic and muscular. They can stretch and shorten, move apart, or be tense or relaxed.
Sounds are generated at the top of the vocal apparatus. The cartilage of the epiglottis is located in the pharyngeal cavity; it branches into two cavities: nasal and oral. The palate separates these two cavities, its anterior part is hard, and the posterior part is soft, otherwise it is called the palatine curtain and ends with a small uvula. When the soft palate is raised and the uvula is leaning against the back of the throat, air flows through the mouth and mouth sounds are produced. When the soft palate is lowered and the uvula is pushed forward, air exits through the nostrils. Nasal sounds are produced.
The volume of the nasal cavity cannot change, so a nasal timbre is obtained, for example, the sounds "m", "n". Due to the presence of movable organs: lips, tongue, soft palate, the oral cavity can change its volume and shape. The tongue is the most mobile organ in the speech apparatus. It can rise to one level or another without forming a closure with the palate, blocking the oral cavity. This creates all kinds of resonance conditions that are necessary for the pronunciation of vowel sounds. This is also facilitated by the lowering and raising of the movable lower jaw.
