The central vowels There three central vowels in english ,/a:/,/e/ /N is a short, half-open unrounded central yowel. it is a lax one /a /is a long, half-close and half-open, unrounded tense central yowel e/ is a short, half-open, unrounded lax central vowel. It only occurs in unstressed syllablesThe central Vowels ◼ There three central vowels in English: /ʌ/ , /ə:/ , /ə/ . /ʌ/ is a short, half-open, unrounded central vowel. It is a lax one. /ə:/ is a long, half-close and half-open, unrounded , tense central vowel. /ə/ is a short, half-open, unrounded, lax central vowel. It only occurs in unstressed syllables