My earpiece has a slight hiss on phone calls for the first few seconds when it connects, then it goes away. And it doesnt happen all the time. Anyone else? edit: placed a handful of calls and tested on another iPhone 5. Did the same thing. I thought at first it didnt, but after listening closing, I hear the same hiss early on in a call for a little then it levels out. Could either be the service or maybe the way the noise cancellation ports are picking up noising that needs to be ironed out in an update? I dunno, not very worried about it anymore. Definitely didnt want to swap this phone anyways, its been perfect otherwise. I dont want to test my chances with a replacement.