The physical hardware switch located in the top-right corner of the iPad and iPad mini has had a somewhat checkered past; while it now defaults to being a mute button, when the original iPad was first released with iOS 3.2 the button was actually used only as an orientation lock, a behaviour that remained in place until iOS 4.2 permanently changed it back to a mute function and then iOS 4.3 gave users a choice. Out of the box, the button works in the same way as on the iPhone and iPod touch—muting all alert sounds such as mail and calendar notifications. Unlike the iPhone and iPod touch, however, you can actually reassign the function of this button to an orientation lock, useful for using your iPad to read or watch videos when lying on your side in bed, for example. To do this, simply go into the Settings app on your iPad, choose General and look for the section labelled “Use Side Switch to” and choose your preferred function. A button can also be found on the multitasking/widget bar that will automatically be set to the other option, so if you choose to reassign the Lock Rotation function to the switch, the widget bar will contain a Mute button.
Keep in mind as well that the “Mute” option—regardless of whether it’s assigned to the switch or the button bar—mutes alert sounds, which are separate from other sounds such as music and video playback. Similarly, turning down the volume using the buttons on the side of the iPad will not silence alerts such as push notifications, calendar alarms and new incoming mail messages.