Dell laptop headphone jack does not work when playing audio and video in Firefox 27

Question

My problem is similar to the one posted in this thread: https://support.mozilla.org/en-US/questions/986978?esab=a&s=laptop+headphones+don%27t+work+with+firefox&r=2&fpa=1&as=s
I believe it has little to nothing to do with extensions.
I have just installed Firefox 27 on the Dell Inspiron 3520 laptop of a friend. She is an unsophisticated user who has a computer for email, simple web browsing, and watching YouTube and other online videos. Because she frequently seems to end up with junk on her machine, I wanted to switch her over to Firefox so I could install ad and script blockers that would hopefully slow down the frequency of adware and malware roosting in her system.
The laptop is a Dell Inspiron 3520 with an Intel celeron CPU (64-bit), running Windows 8. There are standard end-user applications installed (Adobe Reader, VLC Media Player, etc.), but no tweaking utilities, etc. The audio drivers are Cirrus Logic High Definition Audio.
I've been troubleshooting the laptop today trying to track down why the integrated speakers continue to work when the headphones are plugged in, with no sound coming through the headphones. Because I had run a series of virus / malware / adware scans just before installing Firefox, I thought I had mistakenly deleted some system audio files.
It finally became clear after toggling multiple settings, playing with Windows and Dell sound settings, and experimenting, that the headphone audio jack still works as it should in the system itself (for example, playing videos through VLC Media Player) and in Internet Explorer. It is only in Firefox that plugging in the headphones does not send audio through the headphones nor cut out the integrated speakers.
Sometimes there is a silencing of the integrated speakers for a few seconds, but then the audio kicks in again. (I am using YouTube and a certain movie streaming website to test the audio).
However, if the headphones are plugged in before starting the videos, the sound comes through the headphones, but unplugging the headphones, then reinserting them, stimulates problem again. Not only that, but then in YouTube the video will stall and can't be restarted until the page is reloaded.
Again, this is a fresh Firefox install of less than 24 hours, with only Adblock, Adblock Plus Pop-up Addition, Flashblock, and NoScript installed. There are no themes installed and most of the Options are the defaults that are set upon installation.
I have both disabled the add-ons and uninstalled them entirely before testing the headphone funtionality. In both instances the problem persisted. I've also uninstalled and let Windows re-install the Cirrus audio drivers.
Does anyone else have any insight into this problem, and any potential solutions other than "start in Safe Mode" and "reset Firefox"?

Answer 1

Firefox can switch audio devices within ~ a + or - 10 minute period or so (Just a guess). At which point it latches onto the audio device and will never change until the entire process is shutdown (read last paragraph, there is an exception)
Ive had this problem for a few months now, at least. And I switch back and forth from my sound system and my wireless USB headset.
If anything will fix this i believe it would be disabling "Allow applications to take exclusive control of this device" in the properties of your default audio device, but i doubt it. I think this is an issue regarding the code in firefox itself.
I'd like to see this turned into a default feature, being able to disable and enable the ability to stay on whichever device was the default at the time of launch, or to always play on the current default device, even if its changed. That or being able to choose a specific device/devices (WOULD LOVE TO THIS).
Other than that I dont really have a solution, and I kind of doubt anyone will unless its addressed in the next update.
Oh I thought of one solution that doesnt require restarting firefox, disable the current audio device and the sound will automatically switch to the next available device. Or possibly when a new device is introduced?? I havent done much testing on the matter though. This is just my best guess based on my personal experience with firefox.