If you log your audio elements using the command log("play"), your results file will report a line whenever the audio file is played, indicating its name and when it started playing, this way you can tell which was played first by comparing the timestamps. Another option is to store randomAudios[0] and randomAudios[1] in a couple of global Var elements that you log at the end of your newTrial, following the same method as described on this tutorial page.