It seems like every learner goes at a different pace. This means that in multi-learner households, you’ll generally have at least one learner who is faster than another. The general consensus is that you don’t want to hold back your fastest learner. So add words at the pace of your fastest learner. If one of your other learners seems to be frustrated by too many buttons, you can always create a second, smaller soundboard to the side for that learner. If you have one learner who is pushy or protective of the buttons, you might also want to create separate boards for your learners or you can try to make sure that the other learners get time alone with you and the soundboard without your pushier learner around.