Currently media-libs/libvorbis does not provide the 32 kbps Vorbis encoding. As far as I know aoTuV modification lets one encode the audiofiles with 32kbps bitrate, which sometimes is indispensable. So maybe it is worth adding the aoTuV modification to libvorbis? Reproducible: Always
It has been in Portage behind USE flag before, but it was too old and no longer applied to current libvorbis: http://bugs.gentoo.org/show_bug.cgi?id=275436#c2
*** This bug has been marked as a duplicate of bug 275436 ***