When this vibration reaches an ear, it is translated into what we recognize as a sound. Sound vibration must travel through matter. This is typically air. When you say, Hello, to a friend, the air parts (called molecules) vibrate in small waves which travel to the friend and they hear the word Hello..
Continental crust is actually much thicker than oceanic crust. This is because Continental crust has been formed over a much longer period of time, and especially so due to sea-floor spreading (as new crust is constantly produced).
The continental crust is made mostly of rocks with a composition similar to granite (a light-colored rock you would expect to find in the Sierra Nevada), whereas the oceanic crust is made mostly of rocks with a composition of basalt (a dark-colored rock, like the rocks that make up the Hawaiian volcanoes).oth oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. This is partly why the continents are at a higher elevation than the ocean floor.