Muting an Application on a Mac
Is it possible to mute just a single application (ex. Safari) on Mac while letting other application's sound continue to run through?
Solution 1:
You could use Audio Hijack Pro:
It's an advanced mixer initially meant for recording an application's audio.
You can adjust the volume of each application separately and also mute them. It's also fully AppleScriptable, so I guess you could associate keyboard shortcuts to mute a given set of apps.
Solution 2:
I tried BackgroundMusic and it works like a charm (and it's free!)