Forced to use pulse audio with firefox
I use Ubuntu and was not pleasantly surprised that to use Firefox I am forced to use Pulse Audio. I avoid using that sound system because of problems with latency, static noises, and bloat. I found Pale Moon which has direct support for ALSA. It's too bad Mozilla did not bother to warn of the change. Until I used Chrome, and eventually saw the message in Firefox to use Pulse, I thought my sound system crashed. I have removed Firefox and am using Pale Moon or Google Chrome.
Alla svar (1)
Alsa support was dropped starting Firefox 52.0 and later. Some Linux distros may have delayed this change with their own third-party Firefox packages.
You could compile Firefox yourself with --disable-pulseaudio --enable-alsa
Keep in mind that if you do this you will not get updates from Mozilla as it will be a third-party build.
Bug 1247056 - Require PulseAudio to play sound on Linux