I was reading this thread, plus the linked bug submission because I was having similar problems to what people were reporting here.
-My game had glitchy sound on iOS (iPhone5, iOS 9.3.2). On first load the menu music wouldnt start, despite having a touch event prior (to go from a title screen to the menus).
-If I force-closed my game and restarted, the problem above would always occur. But if I just quit out of the app, then come back to it (without force-closing) the music would play as it should at the correct times in menus and cutscenes etc.
-Also my sound effects sounded very 'clipped' or low quality, compared to Android devices.
I was using C2 stable r227. I upgraded to C2 Beta r230 and re-exported for XDK.
This seemed to fix the problem of the music not playing in the menus on first start.
So some fix in C2 from r227 and r230 seemed to help my music play on starting the app.
My sound effects still sound very clipped tho.
Just posting in case this is helpful to anyone.