Contact changes tracking problem in android

I am 开发者_如何学JAVAusing a content observer to listen to contact changes in android 2.x (ContactsContract.Contacts.CONTENT_URI). My problem is ContactObserver's onChange gets called even when I make a phone call. How can i skip these and listen only to address book changes?

Change the Uri to ContactsContract.RawContacts.CONTENT_URI or ContactsContract.Data.CONTENT_URI