Programming Languages, Martials Arts and Computers. The Weblog of Chris Double.
If an application complains that the sound device is locked open you can find out which application that is locking it with lsof. This program lists all open files in the system and which process owns the file. It should be available via most Linux distributions package managers.
$ sudo lsof |grep snd
When using an OpenAL application you can have problems with it not being able to open /dev/dsp or /dev/sound due to it being locked by another device. You can force it to use Alsa to share the source device by adding the following to .openalrc:
(define devices '(alsa))
(define alsa-out-device "plug:dmix")