Roundedness

Lip formation during the articulation of a vowel In phonetics, vowel roundedness is the rounding of the lips, or lack thereof, during the articulation of a vowel. It is the degree and kind of labialization of a vowel. In the International Phonetic Alphabet vowel chart, rounded vowels are the ones that appear on the right in each bulleted pair of letters, and the corresponding unrounded vowels are the ones on the left, with [a] (when central) and the unpaired vowels [ɐ] and [ə] being neutral or unspecified. In most dialects of English, the vowel with the greatest degree of rounding is /u/, as in the word too, though some languages have significantly greater rounding of their /u/ vowel. The contrary articulation to rounded is spread lips, in which the corners of the mouth are pulled away from each other but the lips remain fairly close together. In English, as in most languages, the vowel with the greatest lip-spreading is /i/, as in the word see. When a (back) rounded vowel is pronounced, the lips form a circular opening that is typically wider or smaller according to how open or close the vowel is, while unrounded vowels are pronounced with the lips either spread or relaxed (neut