Comment 10 for bug 1906741

I can add some information to this bug (or what seems to be a bunch of related audio bugs).

In my case it is related to my sound card, switching to and from the soundcard audio causes the bug to appear and disappear.

Line-Out - Built-in Audio : No bug
Digital Output (S/PDIF) - EMU20k2 [Sound Blaster X-Fi Titanium Series] : Occasionally garbled audio

I've added more info about my hardware devices and drivers:

lspci | grep Audio

    00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
    01:00.1 Audio device: NVIDIA Corporation GP102 HDMI Audio Controller (rev a1)
    03:00.0 Audio device: Creative Labs EMU20k2 [Sound Blaster X-Fi Titanium Series] (rev 04)

sudo lshw -C sound

  *-multimedia
       description: Audio device
       product: GP102 HDMI Audio Controller
       vendor: NVIDIA Corporation
       physical id: 0.1
       bus info: pci@0000:01:00.1
       version: a1
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: driver=snd_hda_intel latency=0
       resources: irq:17 memory:fb080000-fb083fff
  *-usb
       description: Audio device
       product: HD Webcam C615
       vendor: Logitech, Inc.
       physical id: 2
       bus info: usb@1:1.2
       version: 0.11
       serial: 27A1DFD0
       capabilities: usb-2.00 audio-control
       configuration: driver=uvcvideo maxpower=500mA speed=480Mbit/s
  *-multimedia
       description: Audio device
       product: 6 Series/C200 Series Chipset Family High Definition Audio Controller
       vendor: Intel Corporation
       physical id: 1b
       bus info: pci@0000:00:1b.0
       version: 05
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: driver=snd_hda_intel latency=0
       resources: irq:34 memory:f9300000-f9303fff
  *-multimedia
       description: Audio device
       product: EMU20k2 [Sound Blaster X-Fi Titanium Series]
       vendor: Creative Labs
       physical id: 0
       bus info: pci@0000:03:00.0
       version: 04
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: driver=snd_ctxfi latency=0
       resources: irq:17 memory:f9200000-f920ffff memory:f9000000-f91fffff memory:f8000000-f8ffffff