I've spent a ton of time looking in all the settings.. no notification pops up. I've read other threads telling me to turn of NFC and Wi-Fi notification. Not sure if it has to do with connecting to new cell towers? I've spent time in almost all the settings menus.. Not sure if it has to do with S-Voice, but it doesn't seem like it. I'm wondering if it has to do with Verizon bloat. This is actually my dads phone, so figuring out the culprit may be a little tougher. I've heard it randomly and he says it happens a lot when he leaves the house.