Comment 61 for bug 696841

Kubuntu 17.10, VLC 2.2.6 here. I encountered a slightly different variant of this issue.

In my case audio files (mp3) would always start playing muted in vlc. When I clicked the mute control in the lower right corner of the VLC application it would correctly unmute and play this file. As soon as another file would start playing vlc would then revert to muted.

I tried the various solutions mentioned on this thread and found that switching the output module to ALSA, selecting any of the two PulseAudio devices available and then restarting VLC reproducibly fixes the issue.

Switching the output module back to PulseAudio and restarting VLC reproducibly makes the erratic behavior described above appear again.