This seams a little bit tricky to me.
I have SUSE 12.1 and sound is working fine. I attached the “Sennheiser USB Headphone PC36” and tried to use it, the youtube uses always the internal sound card. First I thought I need a sound driver, reading the Sennheiser web site I found out, that no driver should be needed, because the PC36 ships with its own sound card.
So I retried configuration, I put the Sennheiser at the first place, tested it, and it works !!! The configuration item in the task bar changed also. Anyway the browser does not use the Sennheiser, but the internal sound card only.
The problem is, how to tell an application which sound card to use ?
This seems a problem of ALSA …
Thank you very much for any advice …