Speech production occurs through the compression of the lung volume that makes the air flow audible due to the vibration of the larynx. Various modifications, such as respiration, phonation, and articulation, transform this sound into speech. In respiration, the energy comes from the lungs while in phonation, the vocal folds convert energy into audible sound. In articulation, the articulators change the intelligible speech (Ladefoged 5).The airstream comprises of the air making the sound while the phonation process includes the vocal cords’ movements in the glottis to produce a sound. On the other hand, the oro-nasal process entails the modification of the flow of air from the glottis, lips, and nose (vocal track). Speech is an important factor in communication. Although speech occurs naturally, the sound production is a complex process. Therefore, the paper will explore the principles behind speech production.
The respiratory system plays a vital role in voice production because it acts as the power source. It provides the air supply necessary to trigger the sound waves. The vocal cords in the larynx move close together obstructing the airflow from the trachea during exhalation. As a result, pressure increases and creates resistance. However, air overcomes the resistance due to the closed vocal cords and passes it. In this process, the vocal folds vibrate creating waves in the air that produces a sound. Afterward, the rush passes the folds. Thus, pressure drops triggering the vocal folds to shut again (Mahendru 50).
The most significant way of categorizing sounds through the use of phonetic features is the source of air. In fact, it shows where the air comes from and how the vocal organs modify it to make a sound. The airstream is the most critical in producing sounds for most world languages (Ladefoged 5). The pulmonic egressive airstream which is the manipulation of the air in the vocal tract that the lungs are exhaling is responsible for the uttered words. The glottalic airstream mechanism involves the closure of the glottis to stop the air (Redford 133).
The process of the glottis preventing air is known as the glottal stop. It is a pulmonic egressive sound as air stays in the lungs. The vocal cords close completely to make sure that no air leaks from the lungs for a brief moment; thus, there is the compression of the air in the pharynx. The glottal stop produces some exclamations in English. When the glottis rises, it pushes the air outward to create ejective sounds. These sounds produce the Caucasus, Native American, and Afro-Asiatic languages (Redford 133). Conversely, when the glottis lowers, it creates a vacuum in the mouth, thus producing an implosive consonant sound. The Swahili language and most of the East African dialects have these implosives. The velaric airstream mechanism, which is common mainly for the Southwest African languages, occurs when the back of the tongue seals air from the lungs to create a relative vacuum. The tongue ratifies the air in the mouth through the backward and downward movement.
The phonation process occurs in the larynx that houses the vocal folds. The gap between the vocal folds is the glottis. When producing sound, the vocal cords can be in various positions. The muscles in the glottis move in such a manner that they affect the sound. The effect of the vocal cords is known as the phonation process (Redford 133). When the glottis closes leaving a narrow opening, the vocal folds vibrate to produce voiced sounds. Alternatively, when it is wide open, there is a reduction of vibration in the vocal cords, which results in voiceless sounds. Specifically, the primary cartilages in this process are the cricoid, thyroid, and the arytenoid cartilages. They rotate and tilt affecting the vocal folds that stretch across the larynx separating the trachea and the pharynx. The air pressure in the vocal folds is under both aerodynamic and elastic forces (Ladefoged 5).
The oro-nasal process is associated with distinguishing the nasal consonants from other sounds. In this process, the vocal tract consists of the oral, nasal, and pharyngeal cavities. The boundaries and surfaces of these cavities are the organs of speech. After the air has gone through the pharynx and the larynx, it goes into the nasal or oral cavity. The part responsible for that selection is the velum.
Articulation is the last step of production. It occurs when the shape of the vocal tract changes modifying the sound the larynx produces. The differences in shape happen when the velum opens or closes due to the movements of the jaw, lips, or tongue. Articulation concerns individual pronunciations and sounds. It focuses on intonation, stress, and rhythm of the syllables producing the word. In articulation, a person changes the sounds from the vocal folds using the tongue, lips, and teeth in recognizable patterns (Mahendru 50).
To conclude, a speech sound is the result of air obstruction and its modification in the vocal tract. It involves three processes: the airstream, the phonation, and the oro-nasal ones. Humans use their tongues, lips, teeth, and other parts of the speech mechanism uniquely. The speech starts with breathing; then formation, which is the vibration of the vocal cords, occurs. Next, the constituents of the oro-nasal process, the nose, mouth, and throat cavities, amplify the sounds. The final stage is articulation, where an individual modifies the sound with their teeth, lips, and tongue in recognizable patterns.