Sound okay under root permissions, but not under user

I can execute the following command under root: % speaker-test -Dplug:front -c2 -l3 -twav speaker-test 1.0.23 Playback device is plug:front Stream.

Source: http://forums.opensuse.org/english/get-help-here/multimedia/444083-sound-okay-under-root-permissions-but-not-under-user.html