i would say something is wrong in that commode of yours. it should not buzz. normal sounds of a crapper are a whoooosh with a gurggle at end , then a gentle hissing that stops after a minute or two, with silence following
janet could you relate more details like when does it "buzz", out of nowhere?, in the middle of day ?or nite? or random?, during flush? after flush? while refilling? also what commode you got? old? new? one piece(tank and bowl 1 thing) ? 2 piece(seperate tank and bowl)? brand name? is it well maintained>? and if i were to ask you to open the tank and look inside during a cycle are you up to the task? are you handy and own tools?
there are many possibilites and rather than sending you down the garden path i would or someone here will answer hopefuly correctly with advice that will rid you ofyour "buzz"while not sending you on a wild goose chase or totally confuseing you with allo sorts of ideas and advice that has nothing to do with your buzzing
be more exact please so no time or effort is wasted