Firefox versions 58 and 59 may be unable to play or record sound on some Linux distributions and desktop environments.

About this issue

If the PulseAudio service, which manages audio hardware, is not already running then Firefox will fail to start it due to sandboxing. Most desktop environments start PulseAudio when you log in and ensure that it remains running, and some newer distributions use systemd to manage restarting it, but if neither of these applies then this problem can occur.

What you can do

If you are affected, try one of these workarounds:

• Run pulseaudio --start --exit-idle-time=-1 from a terminal.
• More advanced: Add that command to a script that's run at login (for example, .xinitrc if you use startx).
• Update Firefox to the latest release.