Articulatory aspect of speech sounds
To analyse a speech sound physiologically and articulatorily some data of the articulatory mechanism and its work should be introduced.
Speech is impossible without the following four mechanisms:
(1) the power mechanism;
(2) the voice production mechanism;
(3) the resonation mechanism;
(4) the obstruction mechanism.
The power mechanism consists of the diaphragm, the lungs, the bronchi, the windpipe (or trachea [tre`ki:a]), the glottis (голосова щілина), the larynx (гортань), the mouth cavity, and the nasal cavity [`kæ-].
The voice production mechanism (the vibration mechanism) consists of the vocal cords, which are in the larynx, or voice box. The vocal cords are two horizontal folds of elastic tissue. They may be opened or closed (completely or incompletely). The pitch of the voice is controlled by the tension of the vocal cords. Voice produced by the vocal cords vibration is modified by the shape and volume of the air passage.
The resonation mechanism consists of the pharynx (глотка), the larynx, the mouth cavity (ротова порожнина), and the nasal cavity (носова порожнина).
The obstruction mechanism consists of the tongue (its parts: blade with the tip, front, back or dorsum); the lips, the teeth, the soft palate with the uvula, the hard palate, the alveolar ridge.
The four mechanisms (the power, the vibration, the resonation and the obstruction mechanisms) work simultaneously and teach speech sound is the result of the simultaneous work of all of them.
When the air from the lungs gets into the larynx, it makes the vocal cords vibrate and produce the sounds of noise, that is, voiced consonants and vowels. The air may pass through the larynx, when the vocal cords do not vibrate and are taken apart. In this case voiceless consonants are produced. When, in the production of consonants, voice prevails over noise, sonorants are produced. The auditory impression of sonorants is that of neither noise, nor voice, therefore some of them are called semi-vowels: /w, j, r/.
Having passed through the vocal cords, the air gets into the pharynx and then, if the soft palate is raised and the way to the nasal cavity is closed, it gets into the mouth cavity. If the soft palate is lowered, and the passage to the stream of air through the mouth cavity is closed, the air passes out of the nasal cavity.
Articulatory differences between vowels, consonants and sonorants depend on the three articulatory criteria. They are:
(1) the presence or absence of an articulatory obstruction to the air stream in the larynx or in the supra-glottal cavities;
(2) the concentrated or diffused character of muscular tension;
(3) the force of exhalation.
On the basis of these criteria, consonantsmay be defined as sounds in the production of which (a) there is an articulatory obstruction to the air stream (complete, incomplete, intermittent (періодичний); (b) muscular tension is concentrated in the place of obstruction; (c) the exhaling force is rather strong.
Vowelsmay be defined as sounds in the production of which (a) there is no articulatory obstruction to the air stream; (b) muscular tension is diffused more or less evenly throughout the supra-glottal part of the speech apparatus [epe`reites]; (c) the exhaling force is rather weak.
Sonorantsare sounds intermediate between noise consonants and vowels because they have features common to both. There is an obstruction, but not narrow enough to produce noise. Muscular tension is concentrated in the place of obstruction, but the exhaling force is rather weak. The English sonorants are: /m, n, η, l, w, r, j/.