For some reason, the sounds for ringers, and alerts/notifications on my mother's iPhone appear to not be playing anymore. Even though the ringer volume in settings is turned up almost to the max, the phone still only vibrates when receiving a call. And when the phone is placed onto it's charging dock, instead of BEEP ing like it normally does, it simply vibrates.
Interestingly, when I fiddle with the ringer volume slider in settings, the test ringtone plays just fine, and music audio can also be played through the built in speaker.
What's going on?