First, I'd like to mention that these are just some random questions I thought up about waves. 1. How can you hear sound through a barrier and why is it muffled when you hear it this way? I know waves are transmitted through materials, so I guess I'm really only asking why the sound is muffled when you hear it through a barrier. 2. Kind of part 2 of my first question, do waves diffract when they are transmitted through a barrier? 3. When waves travel, high frequency waves tend to be more directional because they have a high wavelength, and so they don't spread out much when passing through an aperture. This also explains why low wavelength waves are not as directional, they are not so straight-forward and linear when passing through an aperture any more. Is this right? And also, the waves are at the most circular when the wavelength of a wave is a bout he same size as an aperture. Is all that right? My last topic sort of answered my last question, but I just want to confirm everything. Oh, and I think there was error, this might already accidentally be on another board here, but I meant to have this thread here.Thanks in advance.