Muting IE windows?

Is it possible to mute the individual windows of IE or any internet browser? I wanted to do this when I was playing a game and I wanted to mute the music and replace it with my own. No big deal if the answer is no.

Most websites provide a mute option for their pages. I guess you've looked for a mute control on the game website. Also, the volume control in the tray has a mixer display with volume controls for each application. So perhaps you could turn off the volume for the browser app but keep the volume on for the app that supplies your music.