Is there any rule in MMA about how loud you can scream? I couldn't find one. Makes me wonder if this could be a useful technique. Say you are in half guard and you cup your mouth around your opponents ear and belt out a sound that could cause hearing lose and/or some discomfort to your opponent giving you enough time to execute a move while your opponent reels in pain from your sonic blast? Are there any examples of people using screams as a weapon in combat sports?