Ok, First of all what distro are you using?
Second of all, go to terminal and type in:
then type in your root password, then
and go through this easy wizard.
if you don't have sndconfig, then go to
http://www.rpmfind.net and get it from there.
Third of all go to KDE Control Center and go to sound & mutlimedia.
there go to Sound System and disable "Enable the sound system". jsut tick it so the box is unchecked.
now go to XMMS (if you use it ) and go to its preferences. Now go to Audio I/O plugins and in Output Plugin, make sure you have OSS driver [libOSS.so].
Now you should be able to play sounds.
Hope that helps