#Articulatory classification of speech sounds.
Classification of vowels: 1. According to the horizontal movement of the tongue: front (i:, e, æ); front-retracted (i); mixed (з:, schwa-vowel); back-advanced (u, /, o); back (u:, o:). 2. According to the vertical movement of the tongue: close/high (i:, i, u:, u); mid (e, schwa-vowel, з:); open/low (æ, a:, /, o:, o).
3. According to the position of lips: rounded/labialized (o, o:, u, u:); unrounded/unlabialized (all the rest). 4. According to the degree of muscular tension: tense (all long vowels); lax (all short vowels). 5. According to the force of articulation at the end of the vowel: free - weakens at the end (long monophthongs, diphthongs, unstressed short vowels); checked - no weakening, are pronounced abruptly, are followed by a consonant (stressed short vowels). 6. According to the stability of articulation: monophthongs; diphthongs; triphthongs; diphthongized (i:, u:). 7. According to the length/duration: long; short.
Classification of consonants: 1. According to the type of obstruction and the manner of production of noise: occlusives (stops/plosives - p, b, k, g, t, d; nasal sonorants - m, n, nasal n); constrictives (fricatives - f, v, s, z, ш, ж, dental; oral sonorants - l, j, r, w); occlusive-constrictives/affricates (дж, ч). 2. According to the active speech organ which causes an obstruction: labial (bilabial - b, p, m, w; labio-dental - f, v); lingual (backlingual - k, g, nasal n; mediolingual - j; forelingual - t, d, s, z, n, dental, r); pharyngeal/glottal (h). 3. According to the place of obstruction: dental; alveolar (t, d, n, s, z, l); post-alveolar (r); palatal (j); palato-alveolar (ш, ж, ч, дж); velar (nasal n). 4. According to the presence/absence of voice: voiced; voiceless. 5. According to the force of articulation: fortis (all voiceless); lenis (all voiced). 6. According to the position of the soft palate: oral; nasal.