I could be wrong but I think your carrier has to change that for you. Typically the settings are 3 or 5 rings. You don't have it set to vibrate for the first 2 rings do you?
No I can set it to either ring first or vibrate. I just sometimes don't get to it quick enough before the third ring and then voice mail picks it up.
I will call my carrier to see if they can change it.
Thanks