A vowel is a linguistic sound articulated with the outgoing voiced airstream and without any obstruction in the throat or the mouth. CHAPTER 3.

Classification of Vowels

The acoustic quality of vowel sounds can be varied by (i) raising different parts of the tongue to different heights, (ii) by rounding or not rounding the lips, and (iii) by keeping the nasal passage closed or open. Thus you can have high, mid, low, front and back vowels, and rounded and unrounded vowels, all of which may be either oral or nasalised. The vowels articulated in the inner part of the vowel space are known as centralised vowels and the other vowels are contrastively known as peripheral vowels. CHAPTER 3.