One possible way to narrow this down would be trying to record sound via the microphone. You could try recording with Audacity and if you have the issue with that, depending on the size of the file, attach it to the bug.
-- Sound card noise during VoIP https://launchpad.net/bugs/82324 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
