My system automatically upgraded to the latest version of Firefox 26 on Windows 7 and since it upgraded, I cannot hear any audio files -- either mp3 or ogg. If I try to simply open an mp3 file in Firefox, I see a player and watch the progress of the playback, but I hear nothing.
I believe I've been through every article in Firefox support about playing audio and video and what to do if you don't hear an mp3 in Firefox. None of it has changed anything.
I found the Firefox options for MP3 that give me the choice of "Always Ask", "Use QuickTime Plugin 7.7.4' and "Use Windows Media Player (default)" and have tried both QuickTime Plugin choice and Windows Media Player choice and it has no affect. I SEE the playback, but don't hear it. I use the volume slider in the playback window, but it has no affect. I can hear these mp3 files when I play them in IE or Chrome, so what is the matter?
mp3 files used to play for me. But in the last few days I believe both Firefox and QuickTime versions have upgraded and now I can't get it to work.
Are there particular sites where you have this issue?
If you have any interest in exploring this further:
We had a different thread where the user wanted to add a volume control on MP3s played in Firefox's native MP3 player (this was removed because it was buggy and hasn't been added back yet). I created a script to add a volume control, which could be inserted into the page using a button on the bookmarks toolbar ("bookmarklet"). The volume control starts with the current volume level, which normally is 100%.
I mention this because... if you are having problems on a page where the MP3 player is visible, you could insert the button and see whether the player is starting from 0 instead of 100%. This could indicate a problem in how the site is setting up the audio, or in how Firefox is handling a site's script.