Volume issues

[chickengiblets]

I just got on the computer after my brother, so I'm not completely sure what he did, but when I go to the volume button thing, it's stuck on full volume, but then when I listen to something, no volume even comes out! As you can tell, I'm completely unintelligent when it comes to technology, so can anyone please help??

 

[Satcomer]

Go to System Preferences (in your Dock)->Sound. Then in Sound go to the 'Output' mini-tab and set the volume and output source there.