Comment 17 for bug 1297790

This started happening for me when I upgraded from Trusty to Utopic. And yes, it is a bug, not a feature. Previous versions of Ubuntu always did The Right Thing without asking (admittedly, I've never tried to use a mic/headset, maybe that would have failed before).

I understand that there are technical subtleties here, but at the very least, the popup window shouldn't appear every time the device is plugged in. If there's no way to remember individual devices, there should be a checkbox or something for "assume this answer until I go into the sound settings and say otherwise." If you're worried that people will forget the checkbox and rage on the forums about their microphones not working, maybe add a small bubble on the corner next to the volume icon reminding people they can change, or a menu option in the sound icon dropdown to change settings. Whatever is done shouldn't steal focus from other applications, shouldn't block the view of the center of the screen, and shouldn't require user action under most circumstances.