I have tried as you suggested, but unfortunately this does not provide a solution.
I have tried every value between 4.5 and 1.5 for vadThreshold; but this does not change anything. For values above 4.1 it never perceives my word, and for values below 4.2 it properly perceives my word, but only in very quiet surroundings.
Maybe you misinterpreted the issue in my original post, but the problem is not that it reacts to music; the problem is that it never perceives/reacts to my word anymore once I introduce very soft background noise (for example music, or wind, or anything else; music was just an example/easy to reproduce); so it does not react to the music and it also does not react to my voice/the trigger-word.
In summary: without any background noise (for example very soft music) my trigger-word is detected (almost) every time; however, as soon as I introduce a very soft background noise (for example music playing from an iPhone 3 feet away on very low volume), the iPad/OpenEars becomes completely deaf and never detects my trigger-word anymore, regardless of how loud or close I get.
I do not have this issue when I try the exact same thing with a Raspberry Pi with Pocketsphinx (see opening post); even when I move the iPhone playing music much closer to the mic and turn up the volume, my trigger-word is still detected when I say it.