Apple has built many accessibility features into OS X, and VoiceOver is one of the most prominent. In iOS 5, there are also many preferences that can be activated to make notifications more accessible for the hearing impaired.
We recently received a call from a parent who was assisting his child with an iPhone whose flash LED was always going off. He thought this indicated an impending failure of the device or that something seriously wrong with the unit.
With Small Dog’s assistance over the phone, we found out the culprit behind this behavior—the youngster, possibly unknowingly, had found the accessibility menu for iOS and turned on the LED flash for Alerts. Over the phone, we were able to guide him through how to resolve the issue: Go to Settings, tap General, then look in Accessibility. Turn off “LED Flash for Alerts.”
The Apple guide to accessibility features across all Apple products can be found here.