Roundedness

Roundedness

In phonetics, vowel roundedness refers to the amount of rounding in the lips during the articulation of a vowel. That is, it is vocalic labialization. When pronouncing a rounded vowel, the lips form a circular opening, while unrounded vowels (also called spread vowels) are pronounced with the lips relaxed. In most languages, front vowels tend to be unrounded, while back vowels tend to be rounded. But some languages, such as French and German, distinguish rounded and unrounded front vowels of the same height, while Vietnamese distinguishes rounded and unrounded back vowels of the same height. Gahuku has all unrounded vowels.

In the International Phonetic Alphabet vowel chart, rounded vowels are the ones that appear on the right in each pair of vowels. There are also diacritics, ⟨  ̹  ⟩ (U+0339  ̹ combining right half ring below) and ⟨  ̜  ⟩ (U+031C  ̜ combining left half ring below), to indicate greater and lesser degrees of rounding, respectively. These 'more' and 'less rounded' diacritics are sometimes also used with consonants to indicate degrees of labialization.