Why can't I hear audio books on my new phone?

[AC Question]

I have just upgraded from the Samsung Galaxy S4 to the S6 and reinstalled the Audible app. But when I try to play an audio book I can't hear anything (with and without headphones). I can see it's playing on the screen but no sound is coming out. I've obviously checked the volume is not on mute. Any ideas what the problem could be???

 

[B. Diddy]

Welcome to Android Central! Do other sounds work normally?