Apple Events Crowds

I just watched the iPhone 5 keynote and everytime I see an apple event video I wonder: are those press guys really that excited to scream and whistle or are there always some apple employees in the crowd to "enhance" the experience? I mean I would understand if developers are excited about new features so I'm not talking about wwdc here - but at the event yesterday I would assume that there are mostly people of the press and I can't really imagine them getting that excited.

So maybe somebody who attended one of these events could clear things up for me.