20+ Low Front Lax Unrounded Vowel. Varies with degree of advancement of the vowel. Back vowels have a low f2 frequency;
Monophthongs are vowels pronounced by the fixed speech organs with stable vowel.
Low central (or front) unrounded vowel. Vowels can be categorized according to whether they are rounded or unrounded. Tense vowels are produced when the organs of speech are tense. A monophthong, short, lax, unrounded, front, low/open vowel phoneme of the wide variety.