Firefox - No sound in Firefox - How to fix it

This article identifies several causes (and solutions) of No Sound in Firefox. We assume that you can play sounds on your computer; but when you're in Firefox and on a page which is playing sound--no sound is heard.

If you're looking for Internet Explorer-like sounds when you browse web pages, try the Navigational Sounds extension.

Plug-ins

Most web page sounds are made through plug-ins. For these sounds to work, you need to have the correct plug-in installed. If a plug-in isn't installed, you'll normally see a puzzle piece icon and Firefox will show a yellow bar telling you that you need to install the plug-in.
For help installing a specific plug-in, search for that plug-in on this site.

Plug-in volume controls

Some plug-ins have their own volume controls. Check for a volume control directly on the plug-in or in the right-clickCtrl+click menu.

Flash based videos or media lack sound

If you're only having trouble with Flash-based audio (such as YouTube) but other media (such as Quicktime movies), you may have an issue specifically with Flash.

Windows:

Windows Vista volume mixer

1. Open Firefox and visit a site that should play sound.
2. Click the volume icon in the Windows task bar.
3. Click Mixer. The Volume Mixer window will appear.
4. Make sure the Firefox slider isn't at the bottom.