Incoming call ring sounds like basketball buzzer?

My 5s started sounding like the buzzer at the end of a basketball game intermittently with incoming calls - just a constant loud buzz. Then the screen started going (only 1.5 years old and not abused). I just got a 6s Monday from Verizon. Link to Microsoft Sync in my car for phone calls, and the 6s started doing the same thing last night! Am I getting bad phones from Verizon or is Microsoft killing my iPhones?