While neat, I’m not expecting Wanikani to make this into a listening comprehension app, because, it’s an app about reading.
Initially, it will be hard to recognize spoken words and that’s because it’s a different language skill-set separate from your reading abilities.
I suggest you work on listening comprehension specifically, by taking up the habit of listening to podcasts, anime, Japanese news, JP Dramas or whatever you happen to like. 
Eventually, you’ll start to recognize more and more words and you’ll just know what they mean. You can do it! 
You might find something you’re into here