Ik heb hier wel iets, ooit van een site geplukt. Ik heb hiermee een poging gedaan om het geluid van 2 programma's tegelijkertijd af te spelen. Is mij niet gelukt, maar wellicht lukt het jou wel

"You might want to play a game and listen to music on your favorite music player at the same time. To do this successfully, you will have to use ALSA since it supports this feature the best. On all the music players I know of, you can configure the sound engine, to any module that is available.
The setting is usually found under something like Tools >>> Configure >>> Player Engines.
For games, it is a bit more tricky since there is not always a way to configure the player engine directly. Most games, however, do support the OSS. ALSA has an OSS module that allows OSS applications to use the ALSA driver.
To do this you will need the alsa-oss package
Code:
sudo apt-get install alsa-oss
After doing this step, it is very easy to use alsa-oss. In the shell, you can type 'aoss' then the name of the program name you want to use with alsa-oss."
oja, het is wel engels... Maar wellicht bedoelde je zoiets als dit.