Getting Sound to Work on Firefox and Flash with Linux Ubuntu

Getting sound to work with Flash on Firefox can be quite frustrating using Linux Ubuntu. The usual problem is that although sound does work for the system, there is no sound for flash players (Adobe) on Firefox (e.g., Youtube), although there is usually video.

For starters you can check to ensure the sound configuration is correct for your ALSA mixer, by running in the terminal:
sudo alsaconf

If that doesn't work, you can also try running the following in your terminal, which works for some:
mv ~/.asoundrc .asoundrc.old mv ~/.asoundrc.asoundconf ~/.asoundrc.asoundconf.old

Or, you could try the following in the terminal:
sudo apt-get alsa-oss sudo gedit /etc/firefox/firefoxrc

and then include the line
FIREFOX_DSP="aoss"
within that opened file.

If all else fails (which did for me), go into the Linux repositories and install (or reinstall, if already installed) all ALSA and Flash related software. Do a search for the terms alsa and flash (including the latest Adobe flash player). Install (or reinstall) all related packages you find, just in case. And hopefully, that gets your sound working for flash players in Firefox.

If that still doesn't work, the only thing I would recommend is using another browser, but oftentimes if it doesn't work for Firefox, it isn't going to work with another Linux browser like Epiphany either. So your best bet is to run Internet Explorer using Wine, and that typically works.