iPod touch (4th Generation) Audio Only Working When Changing Volume

My Algebra teacher's daughter's iPod Touch is having a problem with the audio.  It seems to only make sound when you change the volume within the settings app inside iOS.  The volume rocker/buttons do not work (but they do work when headphones are plugged in).  I think it might be on mute deep down in the setting, but I can't seem to find a setting that would suggest so.

 

Thanks in advance for your help

Hm...that is strange. Double check to see if it is up-to-date and have her turn it off and turn it back on. If that doesn't work, back it up then restore it. If that doesn't work, call Apple support.