I've got 2 floppy eared dogs and we've never had a problem

*knocks on wood*
I've told the story before and I'll tell it again.
My parents adopted a Mastiff X from the humane society who had chronic yeast infections. At least once every month for a week he stunk and they had to hold him down and give him ear drops.
They moved up a step in food and they *magically* stopped. Hasn't had an infection in months now.
It is possible that this could affect her hearing if you let it continue without treating it.
I agree witch cshellenburger, get a diagnoses, fix the problem now and change the food.