Hello, I'm having the same issue with sound. I cannot get the "Audio" play to work - no music and no sound effects.
Working on my first app and exported as HTML5 for Intel XDK to test on my iPhone 6 running iOS 9.2 for a test and I noticed there isn't any sound.
Maybe an issue with the files being .OGG?
I would export using Cordova but I received errors when trying to import to Intel XDK stating that I was using an old version of Cordova which I assume is because the plugin for Construct 2 is outdated?
I will explore the the Cordova error on another thread but I wanted to let everyone know about the iOS 9.2 sound issue I was having.