Comment 12 for bug 1906741

I have the same issue on Xubuntu 20.04. I find that just exiting Firefox completely and relaunching it resolves the audio problem on other applications and stays fixed, even after relaunching Firefox, unless I go to a website that causes the issue to start again. So, it seems to be very website specific for triggering it. One website that always triggered it was, strangely enough, www.subway.com. I was in a live meeting with MS Teams (standalone application, not web-based) at the same time, but not 100% sure that MS Teams factored into it except that the audio of the meeting got scrambled up until I exited Firefox. If I went back to that website again, it would happen again.

Unlike the other commenters, I don't even have a webcam on this PC at the moment, so I don't think it's webcam related. But, I do have some other hardware in common with the previous poster -- specifically Radeon and Starship/Matisse Audio. At the time of the incident, the audio (of both MS Teams and Firefox) was playing on the Starship/Matisse Audio port. But based on all of the comments here, it doesn't seem to be sound/video card specific, as I'm seeing both Nvidia vs Radeon and Intel vs AMD throughout this thread.

$ lspci | grep Audio
2d:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Baffin HDMI/DP Audio [Radeon RX 550 640SP / RX 560/560X]
2f:00.4 Audio device: Advanced Micro Devices, Inc. [AMD] Starship/Matisse HD Audio Controller

$ uname -a
Linux sylvester 5.4.0-73-generic #82-Ubuntu SMP Wed Apr 14 17:39:42 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

$ dpkg -l | grep firefox
ii firefox 88.0.1+build1-0ubuntu0.20.04.2 amd64 Safe and easy web browser from Mozilla
ii firefox-locale-en 88.0.1+build1-0ubuntu0.20.04.2 amd64 English language pack for Firefox

$ sudo lshw -C sound
  *-multimedia
       description: Audio device
       product: Baffin HDMI/DP Audio [Radeon RX 550 640SP / RX 560/560X]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0.1
       bus info: pci@0000:2d:00.1
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi bus_master cap_list
       configuration: driver=snd_hda_intel latency=0
       resources: irq:116 memory:fce60000-fce63fff
  *-usb:2
       description: Audio device
       product: Plantronics .Audio 478 USB
       vendor: Plantronics
       physical id: 3
       bus info: usb@5:2.1.3
       version: 2.43
       capabilities: usb-2.00 audio-control
       configuration: driver=usbhid maxpower=120mA speed=12Mbit/s
  *-multimedia
       description: Audio device
       product: Starship/Matisse HD Audio Controller
       vendor: Advanced Micro Devices, Inc. [AMD]
       physical id: 0.4
       bus info: pci@0000:2f:00.4
       version: 00
       width: 32 bits
       clock: 33MHz
       capabilities: pm pciexpress msi bus_master cap_list
       configuration: driver=snd_hda_intel latency=0
       resources: irq:118 memory:fcd00000-fcd07fff