Now listen again, but this time pay attention to what happens as the sound decays in amplitude. Notice that the high-pitch sound at some point becomes inaudible and all that it heard is the low-pitch sound. The lower panel shows the time-waveform after the high-pitch has faded away. Notice that at this point there is only one visible oscillation corresponding to the low-pitch sound. This demonstrates something important - the principle of superposition. According to the principle of superposition all sounds can be broken down into a combination of simple oscillations. We will have alot more to say about this later. In the meantime check out this next sound.
