I am so deaf I cannot use a regular telephone at all. But I consider the iPhone a mini computer that allows me to be in contact with friends and family using text messages. And Verizon gave me a data only plan. My problem: I receive constant voice calls from several unrecognized numbers several times each day (no voicemail left as I have had that turned off) that drive both me and the vibrator alert crazy! Is there a way to turn OFF the voice call alert ONLY while leaving the other alerts/notifications alerts intact? (I see no option under SETTINGS/SOUNDS for NO Ringtone.)