Is there a way to indicate which Firefox tab is making sounds?

I am essentially asking for a Firefox equivalent to the Chrome extension called MuteTab - a way to identify which tabs are making sounds and then mute them accordingly.

Is there a such extension for Firefox? Any other ideas?

This would be especially helpful with websites that sit in the background and then sneak up on you and start making sounds, like with ads. You would have to go through all 100 tabs to find the guilty one and terminate it.

I have noticed that the forum section at Tom's Hardware can start playing embedded videos and make disturbing sound this way when you are not currently viewing tab it's on, even though you have not refreshed the page (although it looks like they automatically refresh the page for you after a given time).

Flashmute and Flashblock are mentioned as alternatives. But they don't really work the same way as MuteTab. Even Mozillazine mentions these tools for in-browser muting of tabs. Trying to download Flashmute only results in Cannot GET /flashmute.aspx. I don't think it's maintained anymore. And Flashblock completely blocks Flash content.

Sources:

• http://geeknizer.com/identify-browser-tab-with-sound/
• http://lifehacker.com/5826592/mutetab-quickly-finds-and-silences-noisy-browser-tabs
• http://www.makeuseof.com/tag/mute-sound-webpages-embedded-audio-flash/
• http://kb.mozillazine.org/Muting_browser

I would suggest avoiding the issue altogether by preventing video/music from automatically playing. Here are three things you can do (together or separately) to help prevent auto playing video/sound.

1. Install AdBlock Plus, which will block most advertisements including those that automatically start playing video/sound.

2. Go to about:config and set media.autoplay.enabled to false. This supposedly stops HTML5 media from autoplaying, though I couldn't find any references to it in the about:config entries on MozillaZine Knowledge Base.

3. Go to about:config and set plugins.click_to_play to true. As you can see, it stopped Youtube from auto-playing this annoying video.
   
   

Track https://bugzilla.mozilla.org/show_bug.cgi?id=486262 for Firefox's response.
Also see http://blog.ffextensionguru.com/2014/01/31/why-firefox-wont-have-a-noisy-tabs-feature/ for an opinion on why this may never happen.
https://addons.mozilla.org/en-US/firefox/addon/click-to-play-per-element/ is a little add-on that can be helpful in avoiding the surprise-sound tab issue.

You can now download the Muter add-on (currently for PC only). Once installed it adds a mute button into the add-on bar in the lower right corner. For Chrome use extension MuteTab.

See: Which Tab In Firefox is Playing Sound?