We all know that cussing, swearing & pornographic speech are prohibited just like gossip & Lashon HaRa, but Rav Kook explains why the Talmud doesn't allow us even to hear negative speech without rebuking. In addition to thought, speech, and action, Rav Kook adds that hearing is super-significant, e.g. one who deafens someone must pay damages not just for his ears, but for his entire body because learning, tradition, and kabbala are transmitted thru hearing. He adds that "if you're not part of the solution, you're part of the problem". Rebuke is not just for the sinner but for the "rebuker" himself (prevents being influenced), and for society and really all mankind.