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Keating, Patricia A., IPA Council votes against new IPA symbol, Journal of the International Phonetic Association, 2012, 42 (2): 245 [2014-04-06], doi:10.1017/S0025100312000114, (原始内容存档于2012-11-11), with only 15 of 30 members voting [by email], the vote was 8 in favor, 7 against. [...] With all 30 members of the Council voting [again six months later], the resolution was defeated: 17 no, 12 yes, 1 abstention. The IPA will therefore not be adding a symbol for this vowel to the alphabet or chart.
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延伸阅读
Barry, William; Trouvain, Jürgen, Do we need a symbol for a central open vowel?, Journal of the International Phonetic Association, 2008, 38 (3): 349–357