Annoying issue with Linux sound
If you insist to reuse the sound device, you have to restart the sound service. This is /etc/init.d/alsasound on Suse Linux. Restarting the sound service will cause termination of locking process (through SIGIO or SIGPIPE I imagine) and release the sound device. After which (in gnome) add back the volume control applet to the application tray in lower right corner.