1. Reboot your iPhone 5.
2. Make sure that the mute switch on the left side of your iPhone is in the UP position.
3. Make sure the volume is adjusted accordingly.
4. Go to Settings - Sounds and make sure that you actually have alert tones set.
5. As stated above, go to Settings - Notification Center and then go through each item to make sure the alert type is set accordingly.
Email and Facebook notifications working but not text notifications. My phone reset during the night Jan 1, 2016. I've tried all these suggestions and still not working. Was there an update that could have caused this? Must fix before work Monday.