Brother you can fixed this problem by going to the Windows "Control Panel", clicking on [Flash Player (32-bit)], then clicking on the [Advanced] TAB at the top, and then clicking on [Delete All] under "Browser Data and Setting" (at the top). This Might solve your sound problem............

Other wise,

1. Delete all the cookies and the temp files from the browsers.
2. Try installing the latest flash player. If the problem still exists then try installing the k-lite codec pack.
3. Click on the below link;

http://download.oldapps.com/K-Lite_Codec_Pack/klcodec330f.exe

1. Install it and then go to: Start > Programs > K-Lite Codec Pack > Configuration > Codec Tweak Tool.
2. Then check the checkbox next to [Registry] Fix non-working system sound and click on next.

Thank You... :)

NIKHIL KURMI, thank you for trying but this is a Linux user and Not on Windows. Please look at the system details, tags and what OS details was mention in OP. There was mention of Ubuntu 14.04 and Linux.

dfrandin, you could ask on http://ubuntuforums.org/

I had a similar issue with openSUSE 13.2 with Flash Player in Firefox/SeaMonkey having no sound after certain updates to audio packages. This was reproducible after installing openSUSE 13.2 a few times in fixing it and then getting updates later. Never did narrow down specific package(s) as I would have reported it.

Make sure you have the latest GStreamer and FFmpeg updates.

Try the Firefox version from the official Mozilla server if you currently use a version from the repositories of your Linux distribution.

• https://www.mozilla.org/en-US/firefox/all/

Ops..! Sorry dear. :( I didn't follow that. Next time i will be careful... :)