Q: I can't use siri on my iphone5s

Okay, so I got an Iphone 5s (iOs7) and I can't seem to find where the option to turn siri on is. I checked and restrictions are off, and my default language is English. It's nowhere under settings. Even holding down the home button only brings up voice control. I was wondering if anyone knew how to fix this or if they had luck in a similar situation?