I can understand the landlord's position as well here, having lived next to a screaming baby and under two toddlers, who spent most of their days bouncing cannon balls, playing with their pet hippos (I guess, from the sound of it) and holding yelling competitions. The landlord is simply worried about having the rest of the house calling him daily complaining about the noise - kids will make noise, after all, and there's little you can do about it..