Silent Mode & Do Not Disturb Mode FAQ
Do Not Disturb Mode
If enabled, you will see a quarter-moon icon in the status bar. The feature is controlled from within the device Settings app, near the top of the list (refer to Do Not Disturb at the main level and also underneath the Notification options).
NOTE: in iOS 7, you can control Do Not Disturb Mode from the Control Center (swipe-up gesture from the bottom of the screen) .
Silent Mode (aka mute)
This is applicable to iPhones and iPads. At this time, iPod Touch devices do not have a Silent Mode. In general, Silent Mode is a mute setting which disables certain system sounds such as alerts and ringers. If you want to hear the sounds associated with alerts you need to disable Silent Mode. However, this is up to you and there are of course many good reasons to keep your device from making noise.
Silent Mode on iPhone
On the iPhone, Silent Mode is controlled by the physical "Ring/Silent switch" which is located on the left side of the phone near the top. When it is in Silent Mode, your phone's ringer is muted as well as all alert sounds. Simply toggle the button to switch between modes.
Silent Mode on iPad
NOTE: in iOS 7, you can control Silent Mode from the Control Center (swipe-up gesture from the bottom of the screen) .
First, try the physical toggle switch next to the volume buttons on the upper right side of the iPad (when holding it in Portrait orientation). If you see a bell icon when you toggle this switch, it is controlling Silent Mode. However, if you see a circle with an arrow, it is setup to lock/unlock screen orientation.
If the physical toggle switch is not setup to control Silent Mode, you will need to access it through the multitasking bar. To do this, double-click the Home button to display the multitasking bar. Then, flick from left to right along the multitasking bar. You will see the mute button on the far-left side. Tap it to toggle Silent Mode on or off.