http://superuser.com/questions/133181/how-to-disable-browser-audio Works in windows machines on a per application basis.
Again - for windows - but firefox specific http://improvefirefox.com/turn-off-sounds-in-firefox/
On a mac, you're stuck with F8 (I imagine) :)
This is a little bit different kind of game. The goal is to make objects in the room disappear by lining them up with the matching color in the background. Some objects will change the background color as they disappear, which will help you eliminate other objects. There are a couple levels where you have to disappear things against the right piece of background and in the right order.
It's also an app for Apple and Android. The app has different levels and more philosophical rambling text. I think the app version is easier because it doesn't seem to have the "get the right order" conundrums.
It's on iTunes and Google Play . The first game is free, the other two are $1.99 each if purchased individually, or $2.99 if you get both.