In June 2011, the IPA Council received a formal request from William Barry and Juergen Trouvain to vote on the adoption of a standard IPA symbol for the central open (unrounded) vowel. This request followed publication in 2008, in JIPA 38(2), of their paper 'Do we need a symbol for a central open vowel?', along with response papers in JIPA 39(2) by Daniel Recasens and Martin Ball, and a further response from Barry and Trouvain, in JIPA 39(3).
The Council debated the issue by e-mail in 2011 and took a vote in June-July 2011. That vote was positive but not conclusive: with only 15 of 30 members voting, the vote was 8 in favor, 7 against. The Executive then decided to bring the issue again to the new Council that would begin its term in August, in hopes of a more decisive vote. Thus in Fall 2011 discussion was re-opened, and after extensive discussion the following resolution, deemed most likely of all the options that had been discussed to be supported, was put to the Council for a vote in December 2011:
I agree with the adoption of [A] (small-cap A) as the IPA symbol for the central open vowel, to be placed on the IPA chart under 'Other symbols'.
With all 30 members of the Council voting this time, 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. No further resolutions were proposed to follow up on this issue at this time.