Here are the differences. (1) 聞かない・・・ 　 You intentionally do not listen to someone. You do not even want to listen. (2) 聞けない You are probably deaf, so you are not able to listen. It is not about your intention, but your disability. (3) 聞こえない The lecturer probably talks really far from you, then it's just hard for you to catch lecturer's voice. Does this make sense for you??

聞かない　 not listen 聞けない cannot listen 聞こえない　inaudible