/s_useOpenAL 0
/snd_restart
^^ That goes into game console, if s_useOpenAL is 0 already, change it to 1 instead. Also don't install tremulous source package but install tremulous-bin, download new client executable from
TJW's site and use that one instead.
Tremulous in Portage is horribly outdated and compiling it makes no sense. 3 out 5 files you compile are never used, the other two are horribly outdated, buggy, both have security issues (buffer overflow in client, multiple DoS vulnerabilities in server), lack some features and custom CFLAGS forced by ebuild creator usually break things (eg. it's not safe to compile ioq3 for i686). I've submitted a bug report, simple patch and new ebuild to Gentoo Bugzilla more than a year ago but it was rejected it because "it was too compilcated" (I wonder how complicated it is compared to say kdelibs) and "they'll wait for next release". That was a year ago. 1.2.0 isn't out and I'm pretty sure it'll take another year before it gets released.
So please go and bump
this bugreport.