Catford notes that most languages with rounded front and back vowels use distinct types of labialization, protruded back vowels and compressed front vowels. However, a few, such as
Scandinavian languages, have protruded front vowels. One Scandinavian language, Swedish, even contrasts the two types of rounding in front vowels (see
near-close front rounded vowel, with Swedish examples of both types of rounding). As there are no diacritics in the IPA to distinguish protruded and compressed rounding, an old diacritic for labialization, , will be used here as an
ad hoc symbol for protruded front vowels. Another possible transcription is or (an open-mid front vowel modified by endolabialization), but it could be misread as a diphthong. Acoustically, the sound is "between" the more typical compressed open-mid front vowel and the unrounded open-mid front vowel .
Features Occurrence ==Notes==