Having configured the kernel in the previous stage, you can now fire up the audio controller of your choice (aumix, alsamixer, kmix or gnome-alsamixer) and adjust the volumes to your liking. In my experience, the alsaconf utility will have set the volume to zero and muted levels to start out and following a reboot.
After you have everything configured to your liking, you should store the settings with the command:
1. /usr/sbin/alsactl store
That will enable you change the settings all you want after saving them, and always be able to fall back to a known good setup. Run it again if you make further changes that you wish to save.
Some distributions don't automatically save and restore the configuration over a reboot. For those that don't, the easiest way to make sure this happens is to append a line to the local startup script (often in /etc/rc.d/rc.local):
1. echo "/usr/sbin/alsactl restore" >> /etc/rc.d/rc.local
A simple way to test whether or not you've got sound is to use ALSA's aplay utility, like so:
$ /usr/bin/aplay /usr/share/sounds/startup3.wav