You can turn silent mode on to quiet your device's notifications. When your device is in silent mode, it will not make a sound to notify you of incoming notifications. You can set it to vibrate to alert you to incoming notifications.
Step 1 of 4:
From the Home screen, drag down the Notification panel.
Step 2 of 4:
Tap the Sound icon.
Step 3 of 4:
Tap the Vibrate icon.
Note: You can also use the Volume buttons to lower the volume to silent.