Did you try opening the mixer on Windows and move Firefox’s (separate) audio slider to 0? Or did you already use this or any other method instead? In other words, what action is ignored after restarting Firefox? Did you previously use an add-on for this (such as Muter) which is no longer supported in Quantum? In that case, you could have a look at e.g. Mute Tab or a similar named one, or perform a search for mute on addons.mozilla.org.

In the windows mixer, there is a slider and a mute button. In the past, I always set the slider to zero, and also set the mute button to mute on the firefox control. Both of those settings revert to full volume and unmuted each time I launch firefox. And that never happened until recently.

I need to rely on those settings remaining unchanged to be sure that nothing cuts in on my recordings.

You can try to set this pref to 0 on the about:config page (default = 1.0):

• media.default_volume = 0

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config

Thank you for responding. I actually asked the wrong question, which you answered correctly. What I was hoping to do is be able to do is to turn on or off the firefox web page audio by using the windows audio control, and have that windows audio control setting stay the same even after closing and restarting firefox. So if I set it to "mute", it stays muted, and if I set it to "unmuted" it stays on until I change it back, regardless of closing and relaunching firefox. I tried other settings (i.e. "2.0", or "3.0") but I don't know what other settings will do, and they didn't seem to affect anything. And now I've noticed that even though the windows audio control for firefox is set to mute, some websites (newsweek, for example) still auto-play audio on the page anyway, even when I set the about:config setting you showed me to "0", and the windows audio control is holding its "mute" setting. This gets more annoying the more I learn about it. Any other suggestions?

@ffredd, give a link to the problem site and let others with FF try it out to see if they can mute the audio as well to see what might work.

For most websites with audio there is a speaker icon on the tab you can toggle on or off. https://support.mozilla.org/en-US/kb/mute-sound-firefox-tabs

Get external sound speakers with power button on the speaker.

Please let us know if this solved your issue or if need further assistance.

Thank you, everyone for responding to my question. It appears now that firefox has made the decision to prevent me from controlling web page audio with the windows audio control in the system tray. I need to find a different browser after using firefox / netscape for decades now. Pkshadow: I remember that a few years ago the speaker control on the tab was a problem, but I haven't seen it for a long time, until just recently. The problem with that is that by the time the icon shows up, the sound is already playing, ruining my recording. The reason this is so irritating is that for the last few years this hasn't been an issue, ever. This was just a very foolish decision by the firefox developers, and it makes firefox absolutely useless to me. As a FORMER devotee to the mozilla products going back to 1996, this means that for the first time in my use of the internet, I am turning my back on mozilla. Everything worked perfectly until recently, and now it doesn't. Mozilla needs to change it back, and give me back the control I had.

ffredd said

After using firefox for years, and turning the browser sound off permanently, firefox now turns the sound back on every time I load firefox. It screws up recordings I make if I browse the internet while recording. Totally messed up, you guys! I need to be able to permanently turn off web page audio.

If I recall I been to pages where they load and audio shows up there is a small Speaker icon on the tab and if you click on it you can mute it. FF itself can't disable those Audio since it comes from the site itself. I can example load YouTube and on each tabs I see a Speaker Icon and if I click on it it mutes. So unless you can give a link for others to see what shows up this would lead me to surmise is a Site issue not a FF problem since FF doesn't have access to those site restrictions.