Theory of phonetics

II. Classifications of Consonants.
Consonants are known to have voice and noise combined, while vowels are sounds consisting of voice only. From the articulatory point of view the difference is due to the work of speech organs. In case of vowels no obstruction is made. In case of consonants various obstructions are made. So consonants are characterized by so-called close articulation that is by a complete, partial or intermittent blockage of the air-passage by an organ or organs. The closure is formed in such a way that the air-stream is blocked or hindered or otherwise gives rise to audible friction. As a result consonants are sounds which have noise as their indispensable and most defining characteristic.
Each sound is known to have three aspects: acoustic, articulatory and auditory and therefore can be studied on these levels. To classify consonants we shall take into account such aspects as work of active organs of speech, place of obstruction, manner of producing the noise, type of obstruction the quantity of voice used.
I . According to the active organs of speech and the place of obstruction:
bilabial backlingual(=velar)
[p], [b], [m], [w ] labio-dental [k], [g], [N]
[f], [v] pharyngeal mediolingual
[h] (=palatal)
[j]
Forelingual

apical-alveolar cacuminal palatal-alveolar apical-interdental
[t], [d], [s],[z],[ l], [n] (=post alveolar) [S], [Z], [C], [G] [T], [D]
[r]
Bilabial – lips are closed
Labio-dental - approach of the upper teeth and lower lip.
Pharyngal – incomplete obstruction appears near the pharynx because of the approach of the root of the tongue and back surface of the pharynx.