How to Disable the iPhone Volume
The Apple iPhone is a combination iPod, cell phone, Internet browser and email device. The iPhone has a volume control button that lets you turn off the ringer and reduce the volume. This is a handy feature when going to movies or other places where silence is golden.
Turn the iPhone to its side and find the volume button and the ringer control switch. This switch is just above the volume control.
Push the ringer control switch down toward the bottom of the iPhone until you see an orange tab at the switch housing. The ringer and volume is now off.
Turn the iPhone on and look for an icon of a bell with a line through it indicating that the ringer and volume is off, and the iPhone is in silent mode. Note that if you have the vibration turned on, the iPhone will vibrate instead of ring.