golinux@??? wrote on 03/08/2017 11:33 AM:
<snip>
> "From Firefox 52 onwards, pulseaudio is a hard requirement for sound on linux. Alsa is unsupported and alsa code will be removed in Firefox 54." (from - https://bugzilla.mozilla.org/show_bug.c ... 47056#c178 )

Seamonkey used to be a thing: http://www.seamonkey-project.org/
I thought it had been killed off years ago but seems to have had a release in December of 2016. Sound works out of the box with ALSA.