I don't mind people yelping or screaming in fright over voice. It's a zombie server so it just builds onto the atmosphere. Jojo will do this sometimes, as will I, and when I hear people do it I'll look over at the radar while laughing.
I hate when people argue on voice, though. I'll mute people a lot for arguing over silly things or getting on people's cases for no reason. I'll admit Jojo has argued on voice a few times but it's usually been instigated.
Anyway, while admins should be maintaining order, we can't be singling people out. There are a few regulars I wish I could always mute but for the most part they're just enjoying themselves and not annoying anyone else, so I won't. The same tolerance should be given to kids like Jojo as well.