Problem:  The Phone rings but there are no click noises when you type a text message.  You can't hear Siri talk.  You can't hear music playing.  But you can hear it all when you use the earbuds.   You have checked the volume controls and mute but everything is on.

Solution:  The phone might be stuck in headphone mode. To fix this, plug your earbuds into your phone then unplug the earbuds.  Do this about ten times.