Welcome,
Sure, my answer on Stack Overflow explained this:
FliteController is asynchronous and any new utterance will override the previous one, which means that if you start two utterances almost simultaneously as in your example, you will only hear the second one. What you want to do is to wait for OpenEarsEventsObserver’s fliteDidFinishSpeaking method to know that the first (or the nth) speech utterance is complete so you can begin the next one.
Do you have specific questions about my explanation that I can answer?