No sound from Firefox using onboard audio
I cannot get any audio from my laptop speakers using Firefox. The behavior literally changed from one day to the next. It worked yesterday, it doesn't today. System sounds and other programs work fine, it's exclusively a Firefox issue. I changed the setting to allow video/audio in autoplay, and some other sites have suggested lowering the security.sandbox level to 2. I really don't want to do that unless it's my only option. Now, when I move my laptop from my "normal" external/USB sound card and use it somewhere else, I have no audio. I've also checked that the correct source is being used and is not muted. Absolutely confuzzled.