Audio AirPlay To Your Apple TV

In addition to being able to mirror newer Macs to Apple TV with Mountain Lion, you can also choose to send only your Mac’s audio to Apple TV. Just select it as your sound output in System Preferences, Sound, Output. Or, option+click on the speaker icon in the menu bar and select the Apple TV. This works well if your Apple TV is plugged into a home theater system, and you don’t necessarily need to turn on the TV or projector to use audio.