upgraded Ubuntu to 8.10 Intrepid Ibex and sound in Firefox 3.0.3 went out on my YouTube videos. The fix is to install extra piece of software from the multiverse repository:
System > Administration > Synaptic Package Manager
flashplugin-nonfree-extrasound
Adobe Flash Player platform support library for Esound and OSS
This is an open Source extension library for the Adobe Flash Player
that enables support for otherwise unsupported sound systems. It
provides the libflashsupport.so plugin. The sound system to use is
automatically detected:* It first tries to detect Esound,
* Next, it checks for OSS.If all of the above failed, it falls back to the ALSA driver that’s
built directly into FlashPlayer 9.For PulseAudio support, see flashplugin-nonfree-pulse.
Dude:
http://onlyubuntu.blogspot.com/2008/11/fix-for-no-sound-issue-in-ubuntu-810.html
That did the job for me, NOTHING else seemed to work so I was glad this did.
sudo killall pulseaudio
sudo alsa force-reload
(Hit the reset confirmation)
and then go to System>Preferences>Sound and change everything to ALSA
Voila, thanks to that guy, woot!
You also can try this:
jemunt.blogspot.com