eah, that's pretty much it.
I believe he was saying that きかない will be interpreted as negative volition (will/do not listen) as opposed to a negated passive* (will/do not hear), probably because where we use "hear" Japanese tends to use 聞こえる. But that's a guess.
*I mean that as a lexical passive and not a morphological passive. I.e., you listen to thing of your own will, but you just naturally hear them as they resonate in your ears whether you want them to or not. The passivity is in the word, not the inflection/conjugation, in other words (i.e., it's not a (ら)れる form).