Can i self monitor an adt alarm system?

We just purchased a home that has an adt system installed. I called to see the cost of activating & she said it will be $40 a month since we do not have a phone line. I thought about buying a self installed alarm that just chimes when someone breaks in since that is the true thing that really scares burglars anyway. Then i wondered can i set my current adt alarm to do this & not use there monitoring service. Just use there system which is already installed?