I've been struggling with this problem for a month now. I've done a factory reset, tested out apps, tested the Wi-Fi widgets and nothing has explained why this happens. Why I switch from 3G/4G to wireless, I either lose the notification sounds immediately or when I go back on the Verizon network. Most times, a reboot or a soft reset doesn't help the problem and I end up uninstalling and reinstalling an app. Is my phone just weird? Has anyone else had this problem and find any solutions? I'm assuming it's a conflict between the radio signal and the speakers, although I still get calls to ring through. Any help would be greatly appreciated!