I mean, here youare in a land literally surrounded by mountains, and the major special trait is your ability to scream loudly and make things occur. So wouldnt those things echo off mountains? Could you Unrelenting Force yourself? I just think its kinda strange that hey have absolutely no echo, even in the form of harmless sound

Well, because they aren't really shouts, when you use Th'um you basicly says fu*k you reality, You are my [censored], and reality listens