I found that fiddling with the sound settings (i.e. switching between alsa and pulseaudio and playing the test sound until the crackling disappears) helps: the noise would disappear until next restart.
The ath5k related periodic noise is unrelated to the absence of the crackling noise while playing music. -- Crackling noise after update to pulseaudio https://bugs.launchpad.net/bugs/301755 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs