The loudest cheer

Mom started bringing Tony to library for story time. When every story finishes, Tony gives the loudest cheer in the whole time. The loud 'Yeah' always put him into center of attention of the whole room. It is hard to teach him what is the right volume to use, as dad cheers pretty loud when he watchs sports. How to tell a one and half year old watching sports is different from listening story? Maybe we just live with it.