Comment 6 for bug 1353013

I'm having this issue too in xubuntu 14.04.1. It often happens when I'm using Alsa, and it is random, sometimes audio works well but then all of a sudden it gets this repeated popping/crackling sound.

When in the normal audio, top shows pulseaudio with 3~5% of CPU usage and pavucontrol with 9~10%, and pavucontrol is like the attach picture.