Hi strat0si,

It could be a couple of things. You might have accidentally muted audio for Firefox. The article Knowledge Base article What to do if Firefox won't play any sounds will show you how to check.

If that doesn't work, you should look at Fix common audio and video issues. This will show you how to troubleshoot any plugin/extension issues that might be impacting your system.

Hopefully this helps!

thanks for your answer i have update all plugins but i have the same problem .I have this problem only with firefox not with other browsner and the audio is not muted .Sorry for my english