This trick works for all browsers installed on the computer.
If you to have any (music, sound effects, etc..) for Flash animations, you can install the small program :Flashmute.
After downloading, simply install an icon appears in the taskbar (the program runs every time Windows starts).
It is possible to hide the icon by right-clicking on it and selecting the appropriate option.
This software can be wrongly detected as infectious by your antivirus. This explanation comes from the fact that the software is grafted to the browser and captures the sounds emitted by other plugins (Quicktime, Flash, Silverlight ...) > this is the role of this software, but it is considered as a suspicious behavior by antivirus, therefore emit some warning.