Comment 6 for bug 1302306

In my case only the standard user is affected. The administrator still has the sound.

I found out that the administrator has:
$ cat .asoundrc
pcm.pulse {
    type pulse
}

ctl.pulse {
    type pulse
}

pcm.!default {
    type pulse
}
ctl.!default {
    type pulse
}

After copying it to the standard user and restarting pulseaudio -k, the sound device appeared.