And I find (spkrman57) Ron's description is right on the money - that these waveforms all ride on top of each other. In fact, every signal can be reduced to a composite collection of sine waves. It can also be viewed as a holistic single wave shape. Both are accurate ways to describe a signal. But one is a "forest view" and the other is a "tree view." The "forest view" is the one that we "hear" - Maybe you could say it's the illusion we percieve. We don't hear the individual pressures or sines and only hear the whole, which requires time and space to develop within.