They are representing the two kinds of loud, one is of personality, and one of volume.
I wonder if there is a positive feedback loop here with the chances of going into critical mass.
Creating a black hole and !$%*!$% the perpetrators into it.
(One can only dream)
Loud Howard and Topper are definitely among my favorite recurring characters. Although, sadly, Loud Howard doesn't work nearly as well in a comics medium - he's much better suited to animation where he can actually be heard.