Open front rounded vowel

The open front rounded vowel, or low front rounded vowel,^[1] is a type of vowel sound that has not been confirmed to be phonetic in any spoken language,^[2] but is occasionally used in phonemic transcriptions for some Germanic languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɶ⟩, a small capital ⟨Œ⟩. It was added to the IPA vowel chart to balance the quadrilateral by filling in the remaining gap for a rounded equivalent of [a].^[3]

While the IPA chart lists this vowel as the rounded equivalent of [a], studies of formant acoustics suggest it is closer to the rounded homologue of [æ].^{[citation needed]}

A phoneme transcribed with ⟨ɶ⟩ is reported for the Amstetten dialect of Bavarian; however, it is phonetically open-mid [œ], pairing with unrounded phonemic /æ/ (phonetic [ɛ]).^[4] Similarly, certain studies of Danish^[5][6] and Swedish^[7] use ⟨ɶ⟩ to transcribe a phoneme that is phonetically open-mid [œ] or near-open [œ̞] (depending on the analysis), where phonemic /œ/ is phonetically raised closer to mid [œ̝].^[6][8] In Maastrichtian Limburgish, the vowel transcribed with ⟨ɶː⟩ in the Mestreechter Taol dictionary^[9] is phonetically centralized, with a height between open-mid [œ̈ː] and near-open [œ̞̈ː]; phonologically, it is the long counterpart of /œ/.^[10]

Some phoneticians, such as Geoffrey K. Pullum, have argued that the co-occurrence of a fully open articulation with rounded lips is a phonetic impossibility. Following the 1989 Kiel Convention, Pullum wrote the following semi-jocular remark:

The [ɶ] symbol for Cardinal 12 survived – the unusable in pursuit of the unspeakable, as Oscar Wilde might have said, since Cardinal 12 is an unpronounceable contradiction in terms with jaws fully open and lips rounded. Perhaps one day it can be acoustically synthesized so we can hear it uttered as nature never intended.^[11]