Milo’s note is humorous, because while it makes sense in a valley where things are silent, it’s still an unexpected way to request entry. Though the Soundkeeper is perhaps right that silence can be beautiful, she’s also missing an important point here: that the silence after the storm, for instance, is only beautiful because it contrasts so greatly with the noisy storm that came before it. And clearly, she understands that she needs sound, or she wouldn’t be calling herself to check in.