I haven't used my microphone in Firefox in years. I tried today, logged into Google Voice, which tells me it can't access the microphone. I set permissions in Firefox's settings. I turned up all the mic settings in alsamixer. I tried https://mdn.github.io/web-dictaphone/ , recommended in another thread here, and it doesn't record either. I can use the microphone outside X, with sox's rec. I also can't record a new greeting in Google Voice. Firefox 100.0.2 , Linux, Slackware 64-bit, all packages updated this morning.