To turn off Do Not Disturb on an iPhone then swipe down from the top-right corner of the screen for the Control Center then Look for the moon icon that shows Do Not Disturb is on. Tap moon symbol to turn off. If the iPhone has a Home button then swipe up from the bottom of the screen. also go to Settings, then Do Not Disturb, and turn off the switch. That process will stop your phone from silencing calls and notifications.