Open-mid front rounded vowel
The open-mid front rounded vowel, or low-mid front rounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents the sound is . The symbol œ is a lowercase ligature of the letters o and e. The sound , a small capital version of the ligature, is used for a distinct vowel sound: the open front rounded vowel. Open-mid front compressed vowel. The open-mid front compressed vowel is typically transcribed in IPA simply as , which is the convention used in this article . There is no dedicated IPA diacritic for compression. However, the compression of the lips can be shown by the letter as (simultaneous and labial compression) or ( modified with labial compression). The spread-lip diacritic may also be used with a rounded vowel letter as an "ad hoc" symbol, but 'spread' technically means unrounded. Occurrence. Because front rounded vowels are assumed to have compression, and few descriptions cover the distinction, some of the following may actually have protrusion. Open-mid front protruded vowel. 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 .