Articulatory and physiological aspect of speech sounds.

To analyse a speech sound physiologycally and articulatorily some data on the articulatory mechanism and its work should be introduced. Speech is impossible without the following mechanisms:

The power mechanism

The vibrator mechanism

The resonator mechanism

The obstructor mechanism

The picture!!!

The power mechanism consists of the diaphragm, the lungs, the bronchi, the windpipe (or trachea), the glottis, the larynx, the mouth cavity, and the nasal cavity.

The vibrator mechanism (or the voice producing mechanism) consists of the vocal cords. They have two horisontal folds of elastic tissue. They may be opened or closed (completely or incompletely). The pitch of the voice is controlled mostly by the tension of the vocal cords. Voice produced by the vocal cords vibration is then modified by the shape and volume of the air passege. Two more sources participate in the production of speech sounds: 1) the turbulent noise, which results from some constriction in the flow of air, 2) the impulse wave, which is formed when the complete obstruction of the flow of air in the mouth cavity is suddenly broken. These sources of speech sounds may work separately or simultaneously. For example: 1) the vocal cords produce vibrations in the articulation of vowel sounds, 2) the turbulent noise helps to produce voiceless constrictive consonants, such as /f, s, ∫/, 3) the impulse source helps to produce voiceless plosive consonants, such as /p, t, k/. The Tow sources – vocal and turbulent participate in the production of voiced constrictive consonants, such as /v, z, ى/. The vocal and impulse sources participate in the production of voiced plosive consonants /b, d, g//

The resonator mechanism consists of the pharynx, the larynx, the mouth cavity, and the nasal cavity.

The obstructor mechanism consists of the tongue – picture!!! – blade with the tip, front, back or dorsum – the lips, the teeth, the soft palate with the uvula, the hard palate and the alveolar ridge.

The four mechanisms work simultaneously and that each sppech sound is the result of the simultaneous work of all of them.

From the lungs the air goes along the bronchial tubes and then into the trachea, at the top of which there is the larynx (a man’s larynx is bigger then that of a woman and can be seen as a projecting lump) with the vocal cords. The vocal cords are two elastic folds which can be kept apart of brought together. The opening between them is called glottis – it’s when we breathe out. If the tense vocal cords are brought together, the air stream forcing an opening makes them vibrate and we hear some voice. If you pronouce a voiced Russian consonant /з/ you can feel the vibrations with your fingers. You won’t hear them if you pronounce a voiceless sound /c/. The vocal cords vibrate about 130 times per minute for a man’s voice and about 230 times per second for a woman’s. Variations in speed (or frequency) of the vibration produce changes of pitch: the higher the frequency the higher the pitch. Longer and larger vocal cords produce slower vibrations – lower frequency and lower pitch. That’s why voices of men are much deeper in pitch then those od women.

There’s one more state of the vocal cords: when they are brought close together and then opened suddenly by the air stream. There comes a sort of coughing noise, a kind of the click of the cords. This sound is called the glottal stop.

The area above the glottis is called the supra-glottal vocal tract. On coming out of the larynx the air stream passes through the pharynx. And the pharynx extends to the soft palate, which directs the air stream either to the nasal cavity ot to the mouth cavity – the two function as the principal resonators. The two cavities are separated by the hard palate, the soft palate (or velum) and the uvula – the very end of the soft palate. The soft palate can move. When we breathe through the nose the soft palate is in its lowered position and is pressed agains the back of the tongue – it’s called velar closure and it’s the position for the nasal sounds /m, n, ŋ/. If you nip your nose you can’t pronounce these sounds. When the soft palate is raised, the uvula forms a full contact with the back wall of the pharynx and the anasal cavity is blocked – velic closure. The air stream goes trough the mouth cavity – this is the most typical position of the soft palate for most of the sounds of many languages. There are sounds having both velic and velar closures: /k, g/.

The soft palate is the furthest part of the palate from the teeth. Most of the palate is hard and is fixed. It’s divided into two sections: the hard palate itself (the highest part of the palate) and the teeth ridge, or alveolar ridge (the part immediately behind the front upper teeth). This ridge is very important in English as many consonants are formed with the tongue touching it or put close to it.

Then, the lower teeth are not very important in making speech sounds, while the upper teeth take part in the production of many of them /f, v/.

And the most important organ of speech is the tongue. It is divided into four sections. The part which lies opposite to the soft palate is called the back of the tongue. The part facing the hard palate is called the front. The one lying under the teeth ridge is called the blade and its extremity is known as the tip of the tongue. By the central part of the tongue we mean the area where the front and back meet. The edges of the tongue are called the rims. The tongue may lie flat or move in the horizontal or vertical directions. Plus it can change its shape (the sides sometimes curve up forming a groove). The ability of the etongue to move diminishes towards the its back.

The last but not the least: the lips. They take up various positions: brought firmly together or kept apart neutral, or rounded, or protruded forward.

So, all the above mentioned organs of speech are classified into active (movable and taking an active part in sound formation) – you tell me which ones (the vocal cords, the tongue, the lips, the soft palate with the uvula,the lower jaw, the lungs) and passive – you tell me (the teeth, the teeth ridge, the hard palate, the walls of the resonators, the back wall of the pharynx).

There are three articulatory criteria on which the articulatory differencies between the vowels, consonants and sonorants depend:

• the presence or absence of an articulatory obstruction to the air stream in the larynx or in the supra-glottal cavities;

• the concentrated or diffused character of the muscular tension;

• the force of exhalation.

On the basis of these criteria consonants are defined as sounds in the production of which:

• there is an articulatory obstruction to the air stream (complete or incomplete, or combination of the two /t∫, dى/, or intermittent);

• muscular tension is concentrated in the place of the obstruction;

• the exhaling force is rather strong.

Vowels are sounds in the production of which:

• there is no articulatory obstruction to the air stream;

• the muscular tension is diffused more or less throughout the supra-glottal part of the speech apparatus;

• the exhaling force is rather weak.

Sonorants are the sounds intermediate between noise consonants and vowels:

• the obstruction is complete or incomplete, but not narrow enough to produce noise;

• the muscular tension is concentrated in the place of obstruction;

• but the exhaling force is rather waek (/m, n, ŋ, l, w, r, j/).