Quiz Questions - Mandatory to listen to audio

I have a number of quizzes in my training (storyline). Currently, whether the question is answered right or wrong, I have it triggered for there to be an explanation read of why it is right or wrong, these are layers in the slide. There is also audio reading the script. However, when I run through the training slides, you can click the continue arrow before the audio on the "correct" or "incorrect" layer is finished. How can I make it mandatory to listen to the whole audio before clicking the continue arrow?