from that comment:
Please help spread the word that when there is no sound, this is a Duolingo issue. There is nothing that the forum participants or even the Esperanto course team can do about it. Support supposedly knows, but it may be helpful for learners to continue to file bug reports so that they know it continues to be an issue and that people care about this.
To file a bug report, go to support.duolingo.com
The audio sounds like he's saying, "Kiel vi volas manĝi?" (How do you want to eat?) Which is a valid question, depending on the circumstance it's used in (as is the case with many of these phrases)
Other than brute force memorizing that this particular one wants "Kiam", I'm not going to get it... This is the third time I've made the exact same error for the exact same reason.
I can see why this one is difficult, but to me it was clear that he was saying "kiam". I could believe "kion" - but not "kiel." Sometimes using a different device or headphones or speakers helps... otherwise just consider it ear training.