I delete the ogg files in my project as @Joannesalfa said and the audio works fine on Iphone4 Iphone5 Ipad2 and mini Ipad , but as it says in the "Disadvantages" section of the Ashley's tutorial "Making an iOS web app with Construct 2":
- Audio won't play until the first touch. However, this is not usually very important and can be easily worked around with a "touch to begin" screen that plays a sound when you touch it.
By the way... I saw your capx and looks very creative... hope when it's finished can be posted to watch it in the Scirra arcade.